2Sxy4YoMama

I went to Tirerack and they recommended the 225/45, but when I do the tire calculation, 235/40 the closest to factory size. In addition, a lot of the members are running on 225/40,but I do not like how it looks and leaning more towards 225/45. Which ones to get?

• 225/45
• 235/40
• 225/40

CLpower

the 45 series will give you a better cushion and if you like it go for it, the difference really isn't that great compared to the 40 series. So get what you like.

SinnedTL

what kind of offset is your wheels with what width....this can help us more in deciding what you should get...

rondog

iTrader: (1)

go with 40 series, they look better, and you stay closer to the overall diameter of the OEM wheels and tires, which means alot in terms of gauge accuracy. you will notice that the ride is a little rigid, but then again it handles better. hope that helps

BoostedM3

I run on 235/40/18s and haven't had problems with scratching yet. They also look better than 225s IMO.

4pumpedCL

I'm running 215/35/19s at 45psi and the ride isn't too harsh. 235/40/18s shouldn't feel much firmer than stock. I'd go for them.

Chris

i depends on the width of your rim... if you have 7.5'' like me... i think you should go with 225... 235 would be more for a 8'' rim. but for sure get the 40 series tire... 45 would be too big lookin

you should've made this post a poll... it would've probably helped you more

BiazonR

I would go with 235/40/18, but if really want to shine get
19"s 235/35/19 w/ AVS sport tires

BLUETYPES

i would to know if u all forget about the load rating for your car, because i think all of the tires that were mention are lower than the factory requirements

BiazonR

That is true but If you put a bigger tire it won't fit. Load rate on
factory 1433 max each tire. Mine 1372 each tire still good because
the car is 3500 lbs. 60/40 weight ratio, you need 2100 lbs. to the front 1372x2=2744 so it's fine

EricL

I haven't looked up every 225/40-18, but the bulk of the tires have a rating of 88 SL. IMO -- this is starting to get a bit low

The XL tires will generally bump the load rating up to 92 in the 225/40-18. The Toyo T1s and the Nitto 555 in the 225/40-18 have a 92 XL rating.

(AS a note, they used to indicate the XL/reinforced casing with a "*" on the Toyo site *and* now they don't. )

EricL

(Are you sure you don’t mean 1356lbs, 91 rating???)

I have a feeling your tires are XL rated, so 60 lbs a tire is not going to make that big a deal (just my opinion).

I guess 60/40 is close enough to the spec. However, the big issue comes when the car is filled to its max gross weight of 4365lbs (USA Type-S -- data from Helms 2001 CL/CLS Manual).

The other issue concerns the meaning of XL -- the stock Michelin tires support that 1433 lbs MAX WEIGHT at 35 PSI. If you look on tire rack and pick a Bridgestone, Pirelli, etc in a SL, you will see that the pressure is rated at the MAX Pressure. So, the question is -- what is the load rating at the pressure in the tire!

Example -- the 235/45-17 Toyos say they have a max pressure of 44 on the new web site, but this is incorrect. The tires support the 97 load rating at 44 PSI, but take a max pressure of 50 PSI (there is a little round dot on the tire with the increased pressure shown inside).

So, if you are only running 32 PSI on SL tires with a load rating of 88@44 PSI, they will need to have 44 PSI in them to support the 1235 lbs!!!


So, just to be clear, the stock tires support the full load of 1433 lbs at 35PSI, but can take 40 PSI max.

-

I’ll redo the calc with 4300 lbs with 60/40 f/rear weight bias:

4300 * .6 = 2580 lbs 2580/2 = 1290 lbs per front tire (car at full load).

Now, the 88 tire that some folks are running supports 1235lbs, where 1290 is needed! In addition the car can go 147 MPH and that means there is a lot of drag force on the tires at speed with additional heating.

Moral of the story – if you have 88 rated tires, don’t pack the car up and don’t drive too fast..

EricL

IMO -- If you don't want to get Toyos or Nittos (or other XL tires), you would probably do well to stick with a 225/45-18 or 235/40-18. The 225/45-18 run about 2% slow, but have a better load rating in most of the "hot" tires.