So I'm getting to the end of the life of my stock Bridgestones (Coupe Sport) and have been looking into what to do next. My tire choice is pretty much settled, PSS, but deciding what sizes to go has been trickier.

I would love to upgrade to some wider shoes for increased traction and I know a lot of people on here change to 245/40/19 & 275/35/19 however I'm not wild about this for a couple of reasons:

1) It increases the stagger. I know our cars are set up to have a bit, but having too much stagger induces under-steer. I'd really like to keep the stagger at most 20mm (stock stagger).

2) The stretch of the tires are pretty different. See the attached PDF for details, but basically the rears will look much more square than the fronts.

3) Our cars (stock) have front tire diameters 0.3 inches larger than the rears. Going with 245/40/19 & 275/35/19 reduces this to a 0.1 inch difference. I'd like to minimize this weight shift.


My question is, has anyone gone with 255/40/19 & 275/35/19? This would keep the front wheels the same diameter, shrink the rear by only .1 inch, and preserves the 20mm stock stagger. Furthermore, the difference in tire stretch would be even less than stock and drastically less than 245/40/19 & 275/35/19.


Anyone see any issues or downsides to this? Is 255mm too wide for front tires?

As a side note, I have 4WAS, I won't have any issues running 275s in the rear will I?

 

Since you're not AWD you can run the 255s in front. Here's a cool tire reference and if you scroll way down there's a rim size calculator where you enter the tire size and it gives you the acceptable rim width range for a specific tire size
Car Bibles : The Wheel and Tyre Bible Page 4 of 4
An 8.5-10" rim is OK for the 255s.
It's too bad the stagger is so minimal on the coupe 19s really kind of defeats the purpose of the stagger

 

Thanks for the reply! So you don't think I'll have any steering issues with the wider tires in front?

I actually like the minimal stagger we have, too much stagger often can induce understeer. It's part of the reason I didn't want to increase the stagger by doing 245m in front with 275mm in rear.

 

I was mainly referring to just a 1/2" difference from F to R, from a visual standpoint there's not much difference, A 245/40/19 & 265/35/19 would be a more natural fit on the 8.5/9" set but the 265 is about .4" smaller and about 1.5% different in diameter but if you don't mind a bit more speedometer error that fit might be more what you're looking for.

 

my person recommendation is to match the rev/mile of the specific tire's youre going to get. I believe the stock S Bridgestones and Non-S Dunlops are around 777. The diameter measurements makes sense in an ideal environment but it doesn't account for the construction of the tire, sidewall bend, etc (pretty much physics). http://www.tirerack.com/tires/tirete...jsp?techid=203

Here's something I wrote Tire Width - Nissan 370Z Forum

if you're going with the PSS, they should be 245/40/19 and 285/35/19, I believe.
- I dont think you're going to be about to fit 285 safely on a 9" rim width. 275 should be fine in the rear.
- 245 should be ideal in the front.

 

So the 255s would be 769 R/Mi while the 275s would be 783 R/Mi. Do you know what the stock tires are?

As for the 245s in front, I don't really want to increase my stagger to 30mm and I'd like to stay closer to stock front/rear hight difference. Do you think handling will be hurt running 255mm fronts on an 8.5 inch wheel as opposed to running the 245s?

 

Here's the OEM specs
http://www.tirerack.com/tires/tires....lar=&tab=Specs
774F 777R R/Mi
Proximity to OEM would favor the 245/285 combo and like Jujubii mentioned the 285s should be on 9.5-11" rims for proper mount.
That's a good point about the Rev/Mile as some tires can be quite different in that regard, even within their own brand. Especially if you're running borderline sizes on an AWD where being a bit loose w/ the numbers can come back to bite you.

 

Hmm, thanks a ton for the advice guys. I'm leaning strongly towards the 245/40/19,front and 265/35/19 rear.

At 75 mph I'll lose about 1 mph on the spedo, no big deal. I keep stock front rear size difference and gain a fair bit of traction. Plus those sizes seem about ideal for our stock wheel widths.

 

If anything it would be a bit tougher to steer no?

 

I have a 2011x , I am looking to buy a set of wheels, If I go 19x8.5 squared can i run 255/40/19 all around? calculator says the difference is only -.06% in diameter. I understand the tire will be stretched a little, but the Mich pss and bridgestone s4 say they can fit that rim. Are there any reasons I can not run this setup?

 

It would work, but 245 all around would likely be better in terms of steering response.

 

I have 2011x to and I run 255/40/19 on all four corners with out any issues. My wheels are 19x9. And with 8.5 wheel don't worry about any stretch. I don't have any with 9" wheels.

 

I don't see any issues with a 255/40-19 up front on a 2wd coupe. The fronts will be 1/2" taller than the 275 rears which is why most use the 245s as they are within two tenths of an inch of each other.