# front tire size



## wd1506 (Dec 30, 2015)

i am coming off a square set up and fitting 305/30/20 rears.
but there seems to be some confusion over what size the fronts tires should be.
please help if you can.


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## terry lloyd (Feb 12, 2014)

just checked mine mpss 305/30/20 rears 275/35/20 fronts


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## wd1506 (Dec 30, 2015)

terry lloyd said:


> just checked mine mpss 305/30/20 rears 275/35/20 fronts


TOP MAN thanks for that.:bowdown1:


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## Chronos (Dec 2, 2013)

terry lloyd said:


> just checked mine mpss 305/30/20 rears 275/35/20 fronts


What he said^^ :smokin:


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## dudersvr (May 7, 2003)

The 888 set is 285/35/20 and 305/30/20, perfect match for the 285 front is 335/30/20 that is identical tyre height but loads run the first combo with no bother as Toyo dont do a 335


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## ACspeedtech (Aug 25, 2011)

dudersvr said:


> The 888 set is 285/35/20 and 305/30/20, perfect match for the 285 front is 335/30/20 that is identical tyre height but loads run the first combo with no bother as Toyo dont do a 335


Exactly right, please do check your sizes on a calculator as there are a lot of setups that will end up overworking the ETS unit and cause transmission problems. Stock is around 0.6-0.7% difference, anything over 1% will start being a little 'active' (you'll see the torque split flicking to AWD on the MFD on part throttle)


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## terry lloyd (Feb 12, 2014)

ACspeedtech said:


> Exactly right, please do check your sizes on a calculator as there are a lot of setups that will end up overworking the ETS unit and cause transmission problems. Stock is around 0.6-0.7% difference, anything over 1% will start being a little 'active' (you'll see the torque split flicking to AWD on the MFD on part throttle)


Good to see a shop getting involved :thumbsup: whats your thoughts on the 305 rears and 275 front set ups


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## Stealth69 (Jan 6, 2005)

terry lloyd said:


> Good to see a shop getting involved :thumbsup: whats your thoughts on the 305 rears and 275 front set ups


that puts them at 1.4% difference........ can't be good right?


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## terry lloyd (Feb 12, 2014)

Stealth69 said:


> that puts them at 1.4% difference........ can't be good right?


Hmmmm thought it was over the 1% thought that was the known size to go for


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## Stealth69 (Jan 6, 2005)

315 would go lovely


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## ACspeedtech (Aug 25, 2011)

To be clear, 'over 1%' will not immediately break it, but it will be a little more active than originally designed. We also see a difference on the model years of cars with the different software versions too.
Best advice is to stick to the minimum tyre size difference you can, if you've non standard tyre sizes, keep an eye on the AWD torque split and check it isn't surging while driving or being overly active on sweeping corners.


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## ACspeedtech (Aug 25, 2011)

Stealth69 said:


> 315 would go lovely


Yep, the 275/35 and 315/30 is good (0.5%), 285/35 and 335/30 is also good (but rather wide, I wouldn't confirm this would clear and defo not on a stock wheel)

Certain model years and software version are a little easier on the differences for sure, just be aware on the torque split when you initially fit non oem sizes.


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## colin41 (Apr 26, 2015)

Am I right in saying a 265-35 x 305-30 combo would be even closer than standard? 
If so I'd sacrifice 10mm on the front for a happier ets unit.

I just checked the new 4s tyre sizes and the 265-35 has a noticeably less load rating.


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## terry lloyd (Feb 12, 2014)

On the MPSS if i remember correctly they either did not do 265 or they did not do them in XL


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## colin41 (Apr 26, 2015)

Michelin Pilot Sport 4 S Press Release - Tyre Reviews
Maybe they do now?


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## Tin (Aug 15, 2010)

terry lloyd said:


> On the MPSS if i remember correctly they either did not do 265 or they did not do them in XL


Yes thats correct, they do them in the cup2 xl size though, 265 & 305.


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## ACspeedtech (Aug 25, 2011)

colin41 said:


> Am I right in saying a 265-35 x 305-30 combo would be even closer than standard?
> If so I'd sacrifice 10mm on the front for a happier ets unit.
> 
> I just checked the new 4s tyre sizes and the 265-35 has a noticeably less load rating.


Yes, those are a very good size combo, I've heard rumours they are bringing a higher load rated 4s out, I think they'll be getting pestered at the Autosport show on Thursday about that.


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## dudersvr (May 7, 2003)

305/30/20 is 27.2" tall, 265/35/20 is 27.3" tall


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## dudersvr (May 7, 2003)

335 rear does clear and still leaves big black lines


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## ACspeedtech (Aug 25, 2011)

Cheers John! 335s on stock wheel with no spacers? Just to confirm for other interested chaps.


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## dudersvr (May 7, 2003)

ACspeedtech said:


> Cheers John! 335s on stock wheel with no spacers? Just to confirm for other interested chaps.


I ran the 335's on my forgelines which are a little wider than stock but I have seen 335's on stock rims, cant comment on spacers as I didnt look that close but ive had 305 on with no clearance issues and low pressure so they would widen a lot on launch.


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## Tin (Aug 15, 2010)

dudersvr said:


> I ran the 335's on my forgelines which are a little wider than stock but I have seen 335's on stock rims, cant comment on spacers as I didnt look that close but ive had 305 on with no clearance issues and low pressure so they would widen a lot on launch.


335s on the stock rear 10.5J rim? that must have been stretched! 

I've seen 345s on a 12J rim which fit nicely and used on track.


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## dudersvr (May 7, 2003)

Tin said:


> 335s on the stock rear 10.5J rim? that must have been stretched!
> 
> I've seen 345s on a 12J rim which fit nicely and used on track.


I think the opposite of stretched dude! If the stock tyre size is 285 a 335 is hardly stretched in fact I would imagine it wobble about like a jelly, my forgelines rears with 305 888 the guy struggled to get them on and the 335 were perfect (for road use) but not as sure footed as dunlops or the 888


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## Tin (Aug 15, 2010)

whoops, yes sorry was thinking about vee dub craze with stretched tyres on wider rims with crazy cambers 

Were the 335 MPSSs? 
R888R 315 fit the 10.5J ok, ideally a 11J is better suited thou


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## dudersvr (May 7, 2003)

Yeah the 335 were MPS ran at about 35 psi not too wobbly but I prefer the Dunlop or 888 for decent roads and track, I did a whole weekend at Dunsfold on the Dunlops and only thing that overtook me was a Radical Id put em not far off the 888 but last about 4 times as long.


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## borat52 (Jan 29, 2006)

MPSS are available in 255/35/20 XL, according to the interweb that makes it a better match for the 305/30/20, but it differs from OEM in that the fronts are smaller than the rears by 0.7% whereas OEM fronts are larger than rears by 0.4%.

Tempted just to change for OEM sizes now.

Any thoughts on running 305/30/20 and 255/35/20?


Also for ref even better sizes:
295/30/20 with 255/35/20
AND
295/35/20 with 255/30/20



The advantage of 295/35/20 is you retain stock speedo readings which are off with 305/30/20 (2mph off at 80mph)


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