Help,

I've been searching TireRack.com and other tires sites for days now. I'm trying to find an alternative for the super expensive 19" Potenza's. My problem is that I'm not sure what sizes I can use without messing up the look or function of the car. Finally to my question, can I use the 225/35/19 on the front and the 245/35/19 on the back of the 05 6MT coupe? There seems to be several less expensive choices in this size range, whereas the OEM 40 series tires seem to be limited to just the super pricey.

Thanks!

 

you got pm

 

I would be interested to know this as well. I will be replacing my OEM tires (at least rears) within the next 4k miles or so. I was wondering what sizes I could use etc. I would like to go with something like Toyo or PS2 but I cant find them in the OEM size. Thanks

 

i would be interested in this as well

 

yes yes me interested too.... however knowing our cars have a staggered set up... i dont think the above would work... but will appericiate any expert responses..

also this post will be moved soon... the moderators love doing that!

 

selling my 19" oem tires here:
https://g35driver.com/forums/archived-sales/88763-fs-oem-19-bridgestone-potenza-re050a-tires.html

 

I called TireRack and they said the following.

Some safe, and appropriate matching f/r sizes for your G35 follow:
245/35R19 f
275/35R19 r
-or-
255/35R19 f
285/35R19 r

The 225/35-19 in the front have insufficient load capacity, so not applicable...
Ironically the prices for these alternatives are higher.

 

I think the best set-up would be 245/35/19 in the front and 265/35 in the rear. This would keep the overall aspect ratio correct and would fit the rims prefectly. I don't know why they wouldn't have suggested this one--this is the most logical choice and what I would be running if the 04 rims were 0.5 inches wider in the back.

 

I'm not ready for tire replacement yet, but I have been looking into it. The best value for me would be the BFG g-force T/A KDW2. They've got pretty good overall ratings with a 300 treadwear and a relatively low prices. The rear 245/40YR19s are available for $241. I spec'd out a different size in the front, a 235/35YR19 for $168. The stock Bridgestone's RE050A in a 245/40YR19 have an overall diameter of 26.9", and the fronts in 225/40YR19 have an overall diameter of 25.1". I read on one of the forums that you need to maintain at least a 1" stagger to keep VDC from triggering. If I went with a 235/35YR19 fronts and a 245/40YR19 rears, the overall diameters would be 25.5" for the front and 26.8" for the rears, giving me 1.3" of stagger. I'm sure they designed in some tolerance as not all tires wear evenly.

 

It looks like 225/35YR19s have an overall diameter of 25.2", within .1" of the OEM tires, so I would think you could go with those if you want closest to stock. I wanted a wider front tire to help get rid of some of the understeer without resorting to changing out bushings and sway bars.

 

I thought this was wierd that the 225/40YR19s would have a smaller diameter than a 35 series. Well, after looking at the spec for that tire on the Bridgestone web site, they listed 26.1" where Tirerack listed 25.1". I would tend to believe Bridgestone's specs more than Tireracks spec for the same tire. Bridgestone does list the same 26.9" for their 245/40YR19s, so that's the same as Tirerack's. If that's the case, there's only .8" of stagger. The closes size that BFG has for that diameter that will fit an 8" wheel is 245/35YR19s which has a 25.8" diameter.

 

Seriously with the prices so expensive for oem Potenza, I rather buy a new set of rims

 

I don't know why you would go with a 235 up front and a 245 in the rear.

In general, when you change tire sizes, if you go two sizes up in width and 1 size down in profile, you will be as close as possible to your current set-up in terms of aspect ratio and front/rear stagger. A 235/35 is going to have even less sidewall than you have now and make for an even rougher ride.


Also, tire height is very dependent upon the rim that the tire is mounted on when it is determined. The wider the rim, the more spread out the tire will be and the lower its overall height.

Lot's to consider

 

Ref original post- PS2s come in stock size. Ref larger sizes, rim width (8") is not within spec for anything larger than a 245, according to tire co spec sheets. Squeezing a 265 on the stock rim, it'll look like a doughnut, and sidewall will be compromised, resulting in rollover, and loss of contact patch and thus, crappy handling.

If I was buying wider wheels, though, I'd go with a 245/265 combo or 245/255 combo to rid some of the understeer.

Spending 50 large ($CDN) on a sports/GT car, but not willing to spend money on a good "car/planet interface"? Struggle to understand the logic of that one. I've ranted on this before, so I'll jump off my soapbox now.

Aspect is not fully the issue- best, easiest way to get a good match is to go into the PDF chart for the tire you're interested in and find "revs per mile". This is the actual rolling circumference, precisely measured, vice the simple method of calculating circumference from the width and aspect. For our coupes, ~780 in back/ ~798 in front, whether you have the 17, 18 or 19 inch option. Cross check that with appropriate rim widths. True enough, finding pairs outside the stock sizes is challenging (i.e. a 235 front option is tough to match to something in back for 19s). Link is for PS2 spec sheet so that you can see what I'm referring to (revs/mile 778/797 for stock size PS2)

http://www.michelinman.ca/assets/pdf...otsportps2.pdf

Unless you use the stock wheels, for '04 and beyond, TPMS sensors are relatively expensive, and like on my winter set-up, without them, you can get a lot of false indications, which are irritating. The worst thing for the TPMS is to change the stance of the car i.e. mismatching front and back. Going a little wider in front and a lot wider in back, for example, would do this. To avoid this, make changes where the "percentage change" front and back are the same, not the absolute change.

Hope all this helps.

Cheers,
D