Michelin Pilot Sports in 265/40/17 and 315/30/18 - fitment issues?

[badddrx7]

I am getting a set of OEM Z06 wheels back from Powder Coating in the near future and want to buy another set of tires to mount on them. I'll remove my Chromies and stock Supertires and store them, run the new ones for awhile and maybe switch back. Does anyone know for sure if I will have any issues running or mounting these tires on STOCK oem Z wheels ? How about issues with ABS or anything ? Like to hear from those who are actually running them.

thanks, Tom

[Mark Olson]

I have been running the 255/40/17 and 295/35/18 and have had no issues, as of tomarrow the rears well be 315/30/18 with the same size fronts. the fronts are 25.1in tall and the 315s are 26.1 I dont expect any troubles. ( I'm running the Pilot Sport Cups)

[badddrx7]

I have researched and researched and everywhere points to the 315/30/18 on the rear with a stock Z06 18x10.5 wheel. The front, well I not so sure of, sticking with the 265/40/17 Pilot will yield the same diameter.

Surely someone is running this combo, or close to it. Speak out if you are, or have comments.

Tom

[RocketSled]

I did a lot of research when I upgraded tires this summer. There are may factors to consider. Click my sig, below. At the bottom of the page is a spreadsheet link. Click it and run the file. It'll tell you if a given front/rear tire size combo will be a problem for TC or AH.

I settled on 315/30-18 in the rear and 285/30-18 up front. No problems whatsoever.

I think 315s are about as wide as you can fit without contact. Some guys are running 335s, but having been under my car with the 315s, I can't image there's much if any clearance for 335s. 345s require modifications, wider fender flares or tubbing.

[badddrx7]

Thanks RocketSled, I do not have Excel installed on my computer, could you run the calculation if you have time and see if the following will work with AH, TC, etc.

315/30/18 rear
265/40/17 front


Or what will work on the front, with stock Z wheels

Thanks, Tom

[Mark Olson]

Just install my tires yesterday and had no problems with TA or AH, I will be driving to Phoenix on Friday on my tires (Michelin Pilot Sport Cups) 315/30/18 on the rear and 255/40/17 front.

[DT04R]

Hey bad -

The 315-30/18 has an overall height of 94.50mm (this is the whole wheel/tire)

The 265-40/17 has an overall height of 106.00mm

The spreadsheet shows a delta of -2.6% in red, which is supposed to indicate too much variance front-to-rear.

FYI, switching to a 275/35-17 front (which would help to remove a little udersteer, especially with the meaty 315 rear) is a delta of only 0.4% (it has an overall height of 96.25

Hope that helps!

DOH! Had to edit this - I've been thinking about an 18" front, and the 275-35/18 is pretty common, but I don't think that's a common fitment for 17", so here's the info for a 265-35/17 (which is available in a Michelin Pilot):

92.75 height with a front-to-rear delta (still using the 315 rear) of 1.5% (which is not highlighted red,)

[badddrx7]

I was going with a 265/40/17 front ( not 35 ) and 315/30/18 rear. The front is the same as stock, which they say they have in Pilot Sports.

So will I be ok on the calculation with the above tire sizes ?

Thanks, Tom

[DT04R]

Hey Tom -

I just quoted my original post - you might have missed (with all the numbers) that the first part had the specific tires you had asked about

Originally posted by DT04R
Hey bad -

The 315-30/18 has an overall height of 94.50mm (this is the whole wheel/tire)

The 265-40/17 has an overall height of 106.00mm

The spreadsheet shows a delta of -2.6% in red, which is supposed to indicate too much variance front-to-rear.

[Tomasy]

I am also thinking about an upgrade in tires. Thanks to all for the comments and info on this thread. This is the kind of info that makes this forum so helpful.

[madvette]

I just ordered two 315 30 18 BFG Drag Radials too put on my stock rear wheels to drag race some. I was just going to leave the 18" HRE 547R's on the front with the 265 35 18 tires on them. Will this cause any problems? 18" front and 18" rears? If it causes any problems then I'll just put the two stock front wheels and tires back on. I was just trying two not go thru the extra trouble of removing the front wheels. I'll put the HRE'S back on after a couple of runs. I have the 18" front and 19" rear's. Thanks

[G-Z06]

can anyone take a pic of the 295's and the 315's side by side?

This would be a huge help for me.

Dont want to spend alot of money if it isnt that big of a difference.

[DT04R]

The other thing to keep in mind (though if you measure the exact same brand/model tire I guess it doesn't matter)...

...but the section width (as indicated by that first number, 295) while it's 295mm vs. say a tire that's 315mm wide, the point they start measuring is not consistent across brands (likely not even across models).

So where a 295/35-18 from company a might start measuring further up the sidewall, company b might put more of that 295mm as width/contact area. That's why you may have heard people say "yeah, but they make a really wide 295", which sounds odd since 295mm = 295mm!

I hear this about BFG's, that they're a little wider than Michelin's or Goodyears. I'm about to replace tires, and I'm going with the BFG G-Force KDs in factory 295/35 rears, and upsizing the front a little to 275/40s (which should reduce the understeer a touch I believe). These are supposed to be incredibly sticky (moreso than the F1 SC's) not fade as much under stress, though at a penalty of slighty worse wear and wet weather grip than the F1's (but I recently decided to stick with stock wheels for street and track events, so I'm going with as aggressive street tire as I can )

Seeya -

DT

Originally posted by GarettO
can anyone take a pic of the 295's and the 315's side by side?

This would be a huge help for me.

Dont want to spend alot of money if it isnt that big of a difference.

[G-Z06]

so 34mm = inch correct?

so these dont even appear to be an inch wider then 295's ?

I really want an aggressive look out the back. Granted I only have 10.5'' rims. But what is the widest possible tire I can fit on these?

[DT04R]

2.54cm = 25.40mm = 1 inch

So a 295 is roughly 11.6 "

DT