# Litchfield recommended tyre sizes but...



## FKPhoto (Dec 20, 2020)

Would the standard size tyres be better for handling and traction for street driving?

My 2015 stage II car squirms and jumps around all over the place under load. Someone on a fb group posted the below. Can I have opinions please.

"When I bought my GTR it had 305 rears and 275 fronts PS4S fitted. It jumped around all over the place when pushed hard. They had been fitted with a previous owner recommended by Litchfield. I did a lot of research around the tyre sizes and choices. The Michelin PS4S is a great tyre and I contacted Michelin direct and also NISSAN for their opinions. Whilst the 305 and 265 tyres appear to have a less percentage tyre equivalence differential there are two issues. Michelin doesn’t support this size tyre being fitted to the standard wheels as the rear is out of the size specification for the rim. This effects the outer diameter of the tyre. Nissan also comment that the design of the differential is optimised using the standard tyre size. However they don’t insist on run flat tyres and also recommend Michelin as an option. I fitted standard size Michelin PS4S and it transformed the handling of the car."


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## dazzabb (Oct 29, 2016)

FKPhoto said:


> Would the standard size tyres be better for handling and traction for street driving?
> 
> My 2015 stage II car squirms and jumps around all over the place under load. Someone on a fb group posted the below. Can I have opinions please.
> 
> "When I bought my GTR it had 305 rears and 265 fronts PS4S fitted. It jumped around all over the place when pushed hard. They had been fitted with a previous owner recommended by Litchfield. I did a lot of research around the tyre sizes and choices. The Michelin PS4S is a great tyre and I contacted Michelin direct and also NISSAN for their opinions. Whilst the 305 and 265 tyres appear to have a less percentage tyre equivalence differential there are two issues. Michelin doesn’t support this size tyre being fitted to the standard wheels as the rear is out of the size specification for the rim. This effects the outer diameter of the tyre. Nissan also comment that the design of the differential is optimised using the standard tyre size. However they don’t insist on run flat tyres and also recommend Michelin as an option. I fitted standard size Michelin PS4S and it transformed the handling of the car."


The issues I had with the bigger tyres were twofold, they tram line alot more than the OEM, where I am in rural N.Yorks that makes quite a difference due to poor road surfaces and I got a heap more stone chips from the bigger rubber in a much shorter period of time.

I have now gone back to OEM, not as good on the track for sure, but IMO better on the road.


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## snuffy (Mar 26, 2014)

FKPhoto said:


> Would the standard size tyres be better for handling and traction for street driving?


I go for Avenue driving as opposed to Street driving - it's much more sedate !


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## FKPhoto (Dec 20, 2020)

snuffy said:


> I go for Avenue driving as opposed to Street driving - it's much more sedate !


That's great thanks


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## harry007 (Feb 5, 2020)

Funny I should read this. I am also struggling for better grip once I went with Litchfield setup. Glad to know I'm not alone on this opinion. I do feel oem GT600 tyres were better.


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## FKPhoto (Dec 20, 2020)

harry007 said:


> Funny I should read this. I am also struggling for better grip once I went with Litchfield setup. Glad to know I'm not alone on this opinion. I do feel oem GT600 tyres were better.


What are you experiencing exactly and when? For me on a straight dry road when I floor it in second or first I can feel the tyres fight and the back end squirms around some before it settles. I bought the car with the Litchfield setup so can't compare to oem wheel setup.


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## Tin (Aug 15, 2010)

What sort of tyre pressures are you using on the MPS4Ss? I've used this combo quite a bit and not had any issues.. with this colder weather, pressures tend to be higher up when cold 32-33psi.. 

Also to add, geometry alignment will also affect rear end grip, when was the last time a geo was done?


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## FKPhoto (Dec 20, 2020)

Tin said:


> What sort of tyre pressures are you using on the MPS4Ss? I've used this combo quite a bit and not had any issues.. with this colder weather, pressures tend to be higher up when cold 32-33psi..
> 
> Also to add, geometry alignment will also affect rear end grip, when was the last time a geo was done?


I picked the car up only a few days ago, don't know if the geo has been done. Here there are no places for a proper setup, just the regular hunter wheel alignment places, which i assume is quite different? Pressure I'm yet to check. Its warmer here around 20 degrees most days, what kind of pressures should I be running?


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## harry007 (Feb 5, 2020)

FKPhoto said:


> What are you experiencing exactly and when? For me on a straight dry road when I floor it in second or first I can feel the tyres fight and the back end squirms around some before it settles. I bought the car with the Litchfield setup so can't compare to oem wheel setup.


Pretty much what your describing, except its worse in wet/ damp conditions. The Dunlop GT600 provided much less drama. Granted its a harsher and louder ride with the Dunlops.

However with the Michelins its quieten downed things a lot. But the stability and general grip is not better than the oem setup. Im currently running 33psi all around. I found this to be the most common pressure people were running. Suits me for now. 

Next tweak for me will be, Whiteline/eibach anti rolls bars.

Thanks
H


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## cotter (Mar 19, 2020)

I've ran oem 4s sizes and now on nearly square set up 285/295, but like Tin said never had a problem putting power down from standard to 700bhp, have also watched plenty videos of higher horsepower cars putting the power down no problem on 4s. Possibly need a good GEO done.


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## Tin (Aug 15, 2010)

FKPhoto said:


> I picked the car up only a few days ago, don't know if the geo has been done. Here there are no places for a proper setup, just the regular hunter wheel alignment places, which i assume is quite different? Pressure I'm yet to check. Its warmer here around 20 degrees most days, what kind of pressures should I be running?


Start with 32psi (cold) and go from there.. 
geo via hunter alignment machine is fine, aslong as the database is upto date with the latest Nissan GTR specs.. Fast road setup with around -1.5degs camber around is a good base.


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## FKPhoto (Dec 20, 2020)

Tin said:


> Start with 32psi (cold) and go from there..
> geo via hunter alignment machine is fine, aslong as the database is upto date with the latest Nissan GTR specs.. Fast road setup with around -1.5degs camber around is a good base.


I read somewhere there is no adjustment ability on the camber?


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## IanJ (Aug 9, 2018)

I'm about to replace the awful OEM Dunlop RF's (they are 3/4 worn and tramline badly), am replacing with PS4S (N0) - and ws going to opt for the Litchfield larger sizes !!, now I'm not sure 
Standard road driving, fast road, decent surfaces mostly.
So whats the recommendation ??? Litchfield size or OEM size ??? dont want to waste a grand on the wrong size
Car is 2015 std power.


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## PaulcbaGtr (Apr 11, 2020)

IanJ said:


> I'm about to replace the awful OEM Dunlop RF's (they are 3/4 worn and tramline badly), am replacing with PS4S (N0) - and ws going to opt for the Litchfield larger sizes !!, now I'm not sure
> Standard road driving, fast road, decent surfaces mostly.
> So whats the recommendation ??? Litchfield size or OEM size ??? dont want to waste a grand on the wrong size
> Car is 2015 std power.


Yes interesting reading this.
Just wondering reading this and it may have no relivance whatsoever,but with the bigger tyres would this active the traction control more readily ? Thing of going oem tyres as Nissan intended the car for next time.


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## cotter (Mar 19, 2020)

FKPhoto said:


> I read somewhere there is no adjustment ability on the camber?


This is definitely wrong mate, not sure where you reading all this.


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## snuffy (Mar 26, 2014)

IanJ said:


> I'm about to replace the awful OEM Dunlop RF's (they are 3/4 worn and tramline badly), am replacing with PS4S (N0) - and ws going to opt for the Litchfield larger sizes !!, now I'm not sure
> Standard road driving, fast road, decent surfaces mostly.
> So whats the recommendation ??? Litchfield size or OEM size ??? dont want to waste a grand on the wrong size
> Car is 2015 std power.


Well, for the last 2 or 3 years (as I recall, might well be longer), the consensus on this forum for alternative tyre sizes has been the 305/265 option. And no one (as far as I can remember at least) has had anything negative to say about said sizes.

Indeed, after reading that most people were opting 305/265 MP4S, that's what I fitted about 2 years. And they are fine, they feel better than the standard size (i can't really explain what I mean by feel better !) to me.


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## cotter (Mar 19, 2020)

snuffy said:


> Well, for the last 2 or 3 years (as I recall, might well be longer), the consensus on this forum for alternative tyre sizes has been the 305/265 option. And no one (as far as I can remember at least) has had anything negative to say about said sizes.
> 
> Indeed, after reading that most people were opting 305/265 MP4S, that's what I fitted about 2 years. And they are fine, they feel better than the standard size (i can't really explain what I mean by feel better !) to me.


Exactly this, i've many friends running 305/265 and big power very happy, some use r888 but still bigger sizes. I reckon if you put your foot down and the GTR don't pull straight you have another problem.


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## cotter (Mar 19, 2020)

And while we're on the subject of oem sizes on 4s tyres i had to change mine as it was affecting the ETS, the rolling radius is not the same from run flats to 4s, hence i took the 285 put on the front and 295 on the rear which was checked by AC on live logging checking wheel speed now spot on. Best to take advice from the experts rather than somebody who read something


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## snuffy (Mar 26, 2014)

cotter said:


> And while we're on the subject of oem sizes on 4s tyres i had to change mine as it was affecting the ETS, the rolling radius is not the same from run flats to 4s, hence i took the 285 put on the front and 295 on the rear which was checked by AC on live logging checking wheel speed now spot on. Best to take advice from the experts rather than somebody who read something


Mine's been going to AC for 6 years now and they have never mentioned not fitting the bigger size tyre. And I've just checked my last two Geo setups they did (last one they set it specifically for motorway driving as that's what I mainly do in mine) and it shows that they altered the camber (since I have the before and after readings), so, as you say, it clearly is adjustable.


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## FKPhoto (Dec 20, 2020)

cotter said:


> Exactly this, i've many friends running 305/265 and big power very happy, some use r888 but still bigger sizes. I reckon if you put your foot down and the GTR don't pull straight you have another problem.


It doesn't pull straight as the back end squirms around almost like it's tramlining on a flat road until its well into third when it settles and powers on. I'm new to ownership and always assumed GTR traction on a straight from a roll or launch was planted hence the post. I'll get the alignment checked and take it from there as I know the tyres are good. Thanks


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## PaulcbaGtr (Apr 11, 2020)

FKPhoto said:


> It doesn't pull straight as the back end squirms around almost like it's tramlining on a flat road until its well into third when it settles and powers on. I'm new to ownership and always assumed GTR traction on a straight from a roll or launch was planted hence the post. I'll get the alignment checked and take it from there as I know the tyres are good. Thanks


What power are you running ?


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## FKPhoto (Dec 20, 2020)

PaulcbaGtr said:


> What power are you running ?


Nothing crazy a stage II setup so maybe around 630/40ish


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## PaulcbaGtr (Apr 11, 2020)

FKPhoto said:


> Nothing crazy a stage II setup so maybe around 630/40ish


Ok sorry, you did say at the start.
It shouldnt jump around at the back like that. Iv the same tyres and size as you,but with nearly 800 ft/Ib and mine digs in and accelerates straight. Id be concentrating on suspension conponents/bushes maybe.


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## FKPhoto (Dec 20, 2020)

PaulcbaGtr said:


> Ok sorry, you did say at the start.
> It shouldnt jump around at the back like that. Iv the same tyres and size as you,but with nearly 800 ft/Ib and mine digs in and accelerates straight. Id be concentrating on suspension conponents/bushes maybe.


Yeah I knew this behaviour wasn't right at this power. I'll do alignment with -1.5 camber all round first, check tyre pressures and then see how it goes. Will try in setting RCR and then RRR and test. If it's still out I'll have to check suspension and bushes. I'm loving the car and its a keeper but I don't feel confident in right now. Not like I feel I should.


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## FKPhoto (Dec 20, 2020)

So this is the current settings, seems things are a fair bit out. Having them set to factory settings.


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## FKPhoto (Dec 20, 2020)

These are the factory settings from the hunter.


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## FKPhoto (Dec 20, 2020)

Here are the before and after alignment values. They were unable to adjust the left front caster for some reason and wouldn't make any adjustments outside the factory values (some kind of policy they have here). 

The car pulls more straight and feels more planted, although flooring the pedal in 2nd still induces some tail happy action it corrects fairly quick.


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## r33dgt (Dec 7, 2018)

FKPhoto said:


> Here are the before and after alignment values. They were unable to adjust the left front caster for some reason and wouldn't make any adjustments outside the factory values (some kind of policy they have here).
> 
> The car pulls more straight and feels more planted, although flooring the pedal in 2nd still induces some tail happy action it corrects fairly quick.
> View attachment 265537


Still shouldn't be stepping out in 2nd, assuming the road is dry. Suggest checking out if your ETS is OK and is actually sending power to the front axel. Common symptom if the ETS is bad , you essentially have a RWD GT-R !


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## cotter (Mar 19, 2020)

These are my settings also through hunter machine, there is a few options available in hunter data base for the GTR, these are maximum performance settings, not sure what your guy waffling about


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## FKPhoto (Dec 20, 2020)

r33dgt said:


> Still shouldn't be stepping out in 2nd, assuming the road is dry. Suggest checking out if your ETS is OK and is actually sending power to the front axel. Common symptom if the ETS is bad , you essentially have a RWD GT-R !


Roads are dry indeed. Sorry what is the ETS and how do you check it?


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## cotter (Mar 19, 2020)

FKPhoto said:


> Roads are dry indeed. Sorry what is the ETS and how do you check it?


ETS, IS YOUR AWD, who is your specialist pal, the fact you couldn't adjust front left says something still not right, mine could adjust all the way to max 2 degree camber


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## r33dgt (Dec 7, 2018)

FKPhoto said:


> Roads are dry indeed. Sorry what is the ETS and how do you check it?


The ETS is essentially a clutch pack in the rear gear box which send power to the front diff via a second prop shaft, when requested to do so by the ECU. On your mfd , you can see the torque split between the front and rear wheels, right? This what the ETS is being told to do (not neccessarilly what it is actaully doing) , juggling the power from the rear to the front. When they fail , they typically stop being able to send power to the front diff. There is a procedure to test the unit , putting the car up on a rand , taking out the prop shaft and putting a torque wrench on the ETS unit's output. I'll dig it out.


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## FKPhoto (Dec 20, 2020)

cotter said:


> ETS, IS YOUR AWD, who is your specialist pal, the fact you couldn't adjust front left says something still not right, mine could adjust all the way to max 2 degree camber


Will take it to those that tuned the car and ask them to check it out. I assume there will be some diagnosis stuff they will do to establish if there is an issue there?


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## FKPhoto (Dec 20, 2020)

r33dgt said:


> The ETS is essentially a clutch pack in the rear gear box which send power to the front diff via a second prop shaft, when requested to do so by the ECU. On your mfd , you can see the torque split between the front and rear wheels, right? This what the ETS is being told to do (not neccessarilly what it is actaully doing) , juggling the power from the rear to the front. When they fail , they typically stop being able to send power to the front diff. There is a procedure to test the unit , putting the car up on a rand , taking out the prop shaft and putting a torque wrench on the ETS unit's output. I'll dig it out.


Right will have it checked out. Will be meeting up with few other GTR owners this week and having a drive in their cars and vice versa to get an idea for what it should feel like.


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## r33dgt (Dec 7, 2018)

r33dgt said:


> The ETS is essentially a clutch pack in the rear gear box which send power to the front diff via a second prop shaft, when requested to do so by the ECU. On your mfd , you can see the torque split between the front and rear wheels, right? This what the ETS is being told to do (not neccessarilly what it is actaully doing) , juggling the power from the rear to the front. When they fail , they typically stop being able to send power to the front diff. There is a procedure to test the unit , putting the car up on a rand , taking out the prop shaft and putting a torque wrench on the ETS unit's output. I'll dig it out.


This is the procedure to test (Taken from a post in the DCT Owners Group facebook group). 
Put the car on the lift, remove the FWD shaft at the transmission, put a nut with low torque NM wrench on and turn the awd clutch....if its less then 8nm or more then 25nm, your AWD clutch is toast . Very important is that it has next to zero "free" movement between left/right rotation changes.


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## FKPhoto (Dec 20, 2020)

r33dgt said:


> This is the procedure to test (Taken from a post in the DCT Owners Group facebook group).
> Put the car on the lift, remove the FWD shaft at the transmission, put a nut with low torque NM wrench on and turn the awd clutch....if its less then 8nm or more then 25nm, your AWD clutch is toast . Very important is that it has next to zero "free" movement between left/right rotation changes.


OK thanks for this. I'll take it to them and see what they can do. Regarding tyre size will swapping out then 275 for 265 whilst leaving the rear at 305 make much difference?


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## r33dgt (Dec 7, 2018)

FKPhoto said:


> OK thanks for this. I'll take it to them and see what they can do. Regarding tyre size will swapping out then 275 for 265 whilst leaving the rear at 305 make much difference?


Doubt you'd notice anything when driving normally, but your ETS will def. be happier. If it's not already dead. Fingers crossed. Rolling radius difference between from an rear really needs to be under 1% for it all to work properly.


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## cotter (Mar 19, 2020)

FKPhoto said:


> OK thanks for this. I'll take it to them and see what they can do. Regarding tyre size will swapping out then 275 for 265 whilst leaving the rear at 305 make much difference?


If you read my post above my ets wasn't happy with oem sizes on 4s i bought the car with them on, car would go into limp mode telling me 4wd was overheating because it thought back wheels were slipping as i was over 1 percent on rolling radius. Hopefully 265/305 fells better and your ETS still ok


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## cotter (Mar 19, 2020)

FKPhoto said:


> OK thanks for this. I'll take it to them and see what they can do. Regarding tyre size will swapping out then 275 for 265 whilst leaving the rear at 305 make much difference?


Get them to check your front left adjustment too.


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## FKPhoto (Dec 20, 2020)

r33dgt said:


> The ETS is essentially a clutch pack in the rear gear box which send power to the front diff via a second prop shaft, when requested to do so by the ECU. On your mfd , you can see the torque split between the front and rear wheels, right? This what the ETS is being told to do (not neccessarilly what it is actaully doing) , juggling the power from the rear to the front. When they fail , they typically stop being able to send power to the front diff. There is a procedure to test the unit , putting the car up on a rand , taking out the prop shaft and putting a torque wrench on the ETS unit's output. I'll dig it out.


OK the MFD is the multifunction display right so I should basically select which screen? I can do a recording maybe of it as I put the power down and see what it's doing. I'm hoping the ETS isn't toast, I'll put the 265s on tomorrow and see how it feels.

Would you suggest just going OEM sizes all round period? Car came with volk racing wheels.


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## FKPhoto (Dec 20, 2020)

cotter said:


> Get them to check your front left adjustment too.


Yeah will do


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## cotter (Mar 19, 2020)

FKPhoto said:


> OK the MFD is the multifunction display right so I should basically select which screen? I can do a recording maybe of it as I put the power down and see what it's doing. I'm hoping the ETS isn't toast, I'll put the 265s on tomorrow and see how it feels.
> 
> Would you suggest just going OEM sizes all round period? Car came with volk racing wheels.


If you want oem tyre sizes dont use 4s i had problems as stated above, lots and lots use 265/305 shouldn't be any problems


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## FKPhoto (Dec 20, 2020)

.


cotter said:


> If you want oem tyre sizes dont use 4s i had problems as stated above, lots and lots use 265/305 shouldn't be any problems


OK will change these out tomorrow for 265/35 front and leave the 305/30 rear.

Is there a way I can check myself if my ETS is shagged via the mfd with some pulls on the new tyre setup?


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## cotter (Mar 19, 2020)

FKPhoto said:


> .
> 
> 
> OK will change these out tomorrow for 265/35 front and leave the 305/30 rear.
> ...


NO mate like R33 says it only tells you what ecu is doing not how ets is working, Jack can put mine on ramps and feel ets through front wheels but this is experience, need to use torque wrench for proper reading


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## Simonh (May 24, 2002)

Find a slippy/wet road, turn traction off and boot it, if all 4 wheels spin then the ets is probably fine...


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## FKPhoto (Dec 20, 2020)

r33dgt said:


> Still shouldn't be stepping out in 2nd, assuming the road is dry. Suggest checking out if your ETS is OK and is actually sending power to the front axel. Common symptom if the ETS is bad , you essentially have a RWD GT-R !


Worst case scenario if the ETS is toast, would it be a matter of having to change out the clutch pack essentially for a new unit?



Simonh said:


> Find a slippy/wet road, turn traction off and boot it, if all 4 wheels spin then the ets is probably fine...


No wet roads here mate lol


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## Skint (Oct 11, 2014)

Should’nt they have about 25 lb/ft of preload?


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## FKPhoto (Dec 20, 2020)

Done some reading around regarding how to establish if your ETS clutches are toast. Some info from Jacks Transmissions 

" There are a few ways to check to see if it is still working.

Watch your wheel spin. If you hit the gas in 3rd or 4th gear, do the rear tires spin out of control with no assist whatsoever from the front? If so, then it's bad.
You can also check to see if it's working in a parking lot. Turn the wheel all the way to the stop and try to accelerate. Do you hear scuffing of the tires? If so, the unit is clamping down and working. You should be able to hear and feel no scuffing if you turn sharply while OFF the throttle. If you hear no scuffing while off throttle and scuffing while on throttle, then you are golden!
One last way to check is to see how much preload the system has. You do this by disconnecting the FWD driveshaft from the trans and attaching a torque wrench to the trans output flange. You should see 15-20nm of resistance while turning it. If you are within that range, you should be OK. If you can't turn it at all, then the system is seized. If it turns easily then you either have our 0 preload unit or the clutches are toast."


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## FKPhoto (Dec 20, 2020)

*Update* fitted 265 / 35 PS4S to the front. Car feels better under hard acceleration, I can feel the car pulling more from the front now as opposed to pushing all from the back, hard to explain. Still a little movement when flooring from second but nowhere near close to what is was before the alignment and tyres. 

Going to be taking my friend's GTR for a drive soon as a point of comparison.


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## IanJ (Aug 9, 2018)

Bit confused now then ? I thought this is what you had on the car? or did you have OEM sized PS4s's?? 
What are you running on the rear??


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## FKPhoto (Dec 20, 2020)

IanJ said:


> Bit confused now then ? I thought this is what you had on the car? or did you have OEM sized PS4s's??
> What are you running on the rear??


Apologies I was running 275 / 35 front and 305 / 30 rear. I've switched up the fronts to 265 / 35 now still PS4S. Typo on original post but later added I was running 275 front.


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## MAFFA (Dec 5, 2020)

Hi all,

Sorry if I’m being stupid but I’m new to the GT-R game & I see all these tyre sizes flying around that confuse me. The reason for this is that every search I put in for tyre size its:

255/40R20 front
285/35R20 rear

I look on Litchfield & they’re saying 265/305. I’m guessing this is the widest tyre you can fit on an oem wheel whilst still maintaining the correct rolling radius. Therefore giving a bigger contact patch. Obviously this would compromise rude comfort...but then you’ve bought a GT-R not a Bentley.

Just looking at pics of mine that is arriving in Jan & I can see it has 255/40R20 PS4s on the front. 

As this is what looks like the recommended tyre size this isn’t or at least shouldn’t be an issue? The reason I ask is that I keep seeing it quoted on here that the recommend tyre size is 265???


Sent from my iPhone using Tapatalk


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## SKNAM (Nov 30, 2018)

You need to look at the rolling radius, not just the tyre size. The stock tyres are Dunlop runflats and a 255/40 R20 in the Dunlop has a different rolling radius to a 255/40 R20 PS4. Same for rears, different tread depths etc between brands. The difference between the front and rears (rolling radius) is supposed to be kept to a minimum. The 265/35 and 305/30 does this (to an extent).


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## MAFFA (Dec 5, 2020)

SKNAM said:


> You need to look at the rolling radius, not just the tyre size. The stock tyres are Dunlop runflats and a 255/40 R20 in the Dunlop has a different rolling radius to a 255/40 R20 PS4. Same for rears, different tread depths etc between brands. The difference between the front and rears (rolling radius) is supposed to be kept to a minimum. The 265/35 and 305/30 does this (to an extent).


Yeah I get rolling radius etc...but didn’t realise the Dunlop’s & PS4’s differed so much? Cups I understand with less tread. Mmm okay so the Michelin’s that I have are wrong then? Something to discuss with the dealer 


Sent from my iPhone using Tapatalk


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## SKNAM (Nov 30, 2018)

Tyres may be OK, depends on difference between front and rear rolling radius. The american tyre sites usually have rolling radius calculators, not sure about UK sites, don't think I've seen one.

The latest Cup 2s (N2) come with 6.5mm tread, probably about the same as latest Dunlops. The PS4s will undoubtedly have a little bit more tread and will last A LOT longer. They are popular, but I couldn't live with their squirm and the bounciness. Cup2s miles better in that respect and dry grip, but only 4-5k usuable miles in them and not great in the wet.

Swings and roundabouts.....


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## cotter (Mar 19, 2020)

MAFFA said:


> Yeah I get rolling radius etc...but didn’t realise the Dunlop’s & PS4’s differed so much? Cups I understand with less tread. Mmm okay so the Michelin’s that I have are wrong then? Something to discuss with the dealer
> 
> 
> Sent from my iPhone using Tapatalk


I had problems with oem sizes on 4s, my ETS wasn;t happy had to change to 285/295 so i could re use rears as brand new


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## IanJ (Aug 9, 2018)

FKPhoto said:


> *Update* fitted 265 / 35 PS4S to the front. Car feels better under hard acceleration, I can feel the car pulling more from the front now as opposed to pushing all from the back, hard to explain. Still a little movement when flooring from second but nowhere near close to what is was before the alignment and tyres.
> 
> Going to be taking my friend's GTR for a drive soon as a point of comparison.





cotter said:


> I had problems with oem sizes on 4s, my ETS wasn;t happy had to change to 285/295 so i could re use rears as brand new


ok - so maybe a stupid question now but I'm starting to get worried that the GTR is too clever !! if I move away from the OEM Dunlop RF's and move to PS4S's in the Litchfield size - do I (someone) need to do anything clever to the car so that it knows its had new tires ??? or is it just fit balance and drive away (geo was done 200 miles ago). I'm starting to get paranoid now that this vehicle is way to sensitive / clever to start moving away from anything other than standard ! 
Apologies if this is a stupid question - coming from a Focus RS - where you could fit and forget !


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## MAFFA (Dec 5, 2020)

SKNAM said:


> Tyres may be OK, depends on difference between front and rear rolling radius. The american tyre sites usually have rolling radius calculators, not sure about UK sites, don't think I've seen one.
> 
> The latest Cup 2s (N2) come with 6.5mm tread, probably about the same as latest Dunlops. The PS4s will undoubtedly have a little bit more tread and will last A LOT longer. They are popular, but I couldn't live with their squirm and the bounciness. Cup2s miles better in that respect and dry grip, but only 4-5k usuable miles in them and not great in the wet.
> 
> Swings and roundabouts.....


I love the PS4s on the A45 but I found that out through trial & error & through the research of my forum members. I do know however that tyres work differently depending on what car they’re fitted to so this may be a testing process to find what works.

Has anyone tried the new Goodyear Eagle F1 SuperSport yet? Heard good things but still overshadowed by the PS4s

Think I’ll do a bit more research & get spares in with my tyre guy 


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## cotter (Mar 19, 2020)

IanJ said:


> ok - so maybe a stupid question now but I'm starting to get worried that the GTR is too clever !! if I move away from the OEM Dunlop RF's and move to PS4S's in the Litchfield size - do I (someone) need to do anything clever to the car so that it knows its had new tires ??? or is it just fit balance and drive away (geo was done 200 miles ago). I'm starting to get paranoid now that this vehicle is way to sensitive / clever to start moving away from anything other than standard !
> Apologies if this is a stupid question - coming from a Focus RS - where you could fit and forget !


It will be ok on litchfield sizes, less than 1 percent keeps ets happy


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## Silverspeed (Nov 29, 2009)

How does 295 for rears go with the ETS?


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## cotter (Mar 19, 2020)

Silverspeed said:


> How does 295 for rears go with the ETS?


GOOD AS LONG AS MATCHED WITH CORRECT FRONTS, MINES 285 WHICH IS UNDER 1 PERCENT


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## Silverspeed (Nov 29, 2009)

If fronts are 265 then are they correct matched also?


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## cotter (Mar 19, 2020)

Silverspeed said:


> If fronts are 265 then are they correct matched also?


Are you sure this advice was giving to me from ALEX WURTZ in Germany also backed up by AC Speedtech
285/295


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## Imire1 (Dec 24, 2015)

Silverspeed said:


> If fronts are 265 then are they correct matched also?


 265 fronts 295 rears gives you *The percentage change is 1.24% and the circumferece change is 8.5mm.*


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## Imire1 (Dec 24, 2015)

265 fronts 305 rears *The percentage change is 0.36% and the circumferece change is 2.5mm.

That's from Alloy wheels .com site it lets you compare two tyres. so don't shoot the messenger 

Stu*


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## MAFFA (Dec 5, 2020)

Imire1 said:


> 265 fronts 305 rears *The percentage change is 0.36% and the circumferece change is 2.5mm.
> 
> That's from Alloy wheels .com site it lets you compare two tyres. so don't shoot the messenger
> 
> Stu*


That’s what Litchfield quotes











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## cotter (Mar 19, 2020)

MAFFA said:


> That’s what Litchfield quotes
> 
> 
> 
> ...


Expensive now


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## MAFFA (Dec 5, 2020)

cotter said:


> Expensive now


Yeah. Hopefully my tyre guy can get them a lot cheaper. Was getting PS4S for my A45 AMG at £400 a set when they retail at £600-£650 


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## cotter (Mar 19, 2020)

MAFFA said:


> Yeah. Hopefully my tyre guy can get them a lot cheaper. Was getting PS4S for my A45 AMG at £400 a set when they retail at £600-£650
> 
> 
> Sent from my iPhone using Tapatalk


800 good price now for GTR


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## FKPhoto (Dec 20, 2020)

I paid £520 for a pair of 265/35 ps4s
Previous owner had paid £1200 for a pair of 305/30 rear and 275/35 front PS4S.


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## snuffy (Mar 26, 2014)

My last ones (305/30 and 265/35 PS4S) where £1056 for everything, in Feb 2019.


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## FKPhoto (Dec 20, 2020)

snuffy said:


> My last ones (305/30 and 265/35 PS4S) where £1056 for everything, in Feb 2019.


What I paid is really cheap out here in Qatar, normally pay considerably more.


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## cotter (Mar 19, 2020)

snuffy said:


> My last ones (305/30 and 265/35 PS4S) where £1056 for everything, in Feb 2019.


GIVE US A BELL NEXT TIME, WILL GIVE YOU A CONTACT


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## snuffy (Mar 26, 2014)

cotter said:


> GIVE US A BELL NEXT TIME, WILL GIVE YOU A CONTACT


Thanks, I will. 

As I recall, that was the best I could get at the time from any of the national/well known places.


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## mjr35 (Mar 5, 2013)

I am about to fit a set of Michelin PS4S this week ( 265/40/R20 - F 305/35/R20 - R). Has anyone else fitted these sizes to their R35 ? Mike


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## SKNAM (Nov 30, 2018)

Different profile to the "normal" sizes. Will be interesting to see how you get on. Out of interest, what made you go for those sizes?


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## MAFFA (Dec 5, 2020)

snuffy said:


> My last ones (305/30 and 265/35 PS4S) where £1056 for everything, in Feb 2019.


I asked my tyre guy & he can get me a set in that size for £650 . Feel a lot better about tyre replacement day now 

Thankfully running my old car club I made a LOT of contacts


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## adz87kc (Jan 8, 2018)

MAFFA said:


> I asked my tyre guy & he can get me a set in that size for £650 . Feel a lot better about tyre replacement day now
> 
> Thankfully running my old car club I made a LOT of contacts
> 
> ...


That's a great price.
I paid £856 delivered for N0 spec tyres.


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## mjr35 (Mar 5, 2013)

SKNAM said:


> Different profile to the "normal" sizes. Will be interesting to see how you get on. Out of interest, what made you go for those sizes?


Thanks I will let you know. I was keen to see if anyone amongst the group had put the same boots on ?

Why i went for those sizes ? 
Not sure if your definition of normal sizes is OEM Sizing or 265/35-305/30 
1. Wanted a bit more Tyre width within the Guards vs OEM (without spacers)
2. I needed to at least maintain the OEM Ride height Tyre Diameter (OEM Dunlop - 711mm / PS4S 265/35-305/30 - 690mm / PS4S 265/40-305/35 - 721mm) 
3. Ensure Circumference Difference Front : Rear is minimal (OEM Dunlop 0.69% / PS4S 265/35-305/30 - 0.37% / PS4S 265/40-305/35 0.27%)

Michelin Australia has only just started to make PS4S 305/35/R20 available.


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## MAFFA (Dec 5, 2020)

adz87kc said:


> That's a great price.
> I paid £856 delivered for N0 spec tyres.


Yes he always does me right. I was getting a set of 4 for the A45 for £400 when they were £600-£650.

I’ve a guy for brakes as well when I need them which will also help 


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## Mozzer 09 black edition (Sep 28, 2020)

MAFFA said:


> Yes he always does me right. I was getting a set of 4 for the A45 for £400 when they were £600-£650.
> 
> I’ve a guy for brakes as well when I need them which will also help
> 
> ...


Are you giving out the details as could do with a set myself, best I’ve found is £800.


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## MAFFA (Dec 5, 2020)

Mozzer 09 black edition said:


> Are you giving out the details as could do with a set myself, best I’ve found is £800.


Unfortunately not at the moment. He offered me mates rates on the A45 & is doing the same on the GTR. With the A45 tyres it did lead to him getting more & more as the size was pretty common & fit the Golf R, Focus RS etc... so ended up being quite lucrative. 

Only down side was you had to collect from West Sussex. Not an issue for me as that’s where I live.

I’ll speak to him when I get a set to see if he would consider branching out 


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## GTRBAI (Jan 17, 2021)

Hi everyone, if going with 285/35R20 in the front and 295 in the rear. What should be the height? 35 or 30R 20?


Thank you


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## mjr35 (Mar 5, 2013)

GTRBAI said:


> Hi everyone, if going with 285/35R20 in the front and 295 in the rear. What should be the height? 35 or 30R 20?
> 
> 
> Thank you


I would think 295/35R20 in rear. I was told not to exceed 1% Circumference difference front to rear.


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## MAFFA (Dec 5, 2020)

Mozzer 09 black edition said:


> Are you giving out the details as could do with a set myself, best I’ve found is £800.


I believe there’s a set for sale on here unless they’ve gone now but I think they were £750


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## MAFFA (Dec 5, 2020)

Mozzer 09 black edition said:


> Are you giving out the details as could do with a set myself, best I’ve found is £800.


Brand new Michelin PS4S 265/35 R20 front and 305/30 R20 rear








Brand new Michelin PS4S 265/35 R20 front and 305/30 R20 rear


I've got a full set of PS4s that I bought from Steve sitting in my garage and don't think I'll need them for another 3 months. Anyone want them at below my cost price, then I'll buy a new set when I need them. £750, located in Surrey.




r.tapatalk.com






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## GTRBAI (Jan 17, 2021)

mjr35 said:


> I would think 295/35R20 in rear. I was told not to exceed 1% Circumference difference front to rear.
> 
> View attachment 265930


Thank you for this MJR35


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## Mozzer 09 black edition (Sep 28, 2020)

MAFFA said:


> Brand new Michelin PS4S 265/35 R20 front and 305/30 R20 rear
> 
> 
> 
> ...


Awesome, cheers for this


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