tire size equivalents

[mrr23]

here's a quick list of tire sizes for the f-body. with these tire sizes, there is no need to recalibrate the PCM because they are all the real close to the factory height.

245/50-16 = 25.7"
245/45-17 = 25.7"
275/40-17 = 25.7"
315/35-17 = 25.7"
245/40-18 = 25.7"
275/35-18 = 25.6"
285/35-18 = 25.9"
315/30-18 = 25.5"
335/30-18 = 25.9"
245/35-19 = 25.8"
285/30-19 = 25.7"
295/25-20 = 25.7"


what you do is shorten the sidewall of the tire to accomodate the larger diameter wheel. all will be same height, just in different widths. then, depending on the offset and width of the wheels you buy, will determine if you need to 'clearance' the inner fenderwell or not. then, depending on how much you lower the car, and offset/width of the wheel, will determine if it will hit the outer fenderlip.

[wabmorgan]

So, how tall is a p285/35-18???

I ask becase I think I would rather be a little taller than shorter.

[mrr23]

25.9" tall. you can go to tirerack.com and find all these answers.

[uwilluz]

i was told there was no need to reprogram the pcm unless you had 5mph difference over stock which would effect your abs. that would allow a few more tire sizes. last year i ran 235 40 17 fronts and 275 40 17 rears with no problem. 265 40 17 fronts this year, no problems

[mrr23]

i put my 26" ET streets on my black car with some worn down 245/50-16 tires on the front. so, guessing they were about 25.5" tall. ABS light came on and when braking it activated the ABS system. pain at 120 mph after going through the traps at the track.

[PaganEgyptian]

26" is factory hieght for the V-6 side of the house.
though you can use the V-8 size option.

215/60R16 = 26.1" * not recommended due to wide wheel sizes on 98+, ok on pre 98's with 16x7 wheels
235/55R16 = 26.1"
255/50R16 = 26.1"
285/40R17 = 26.1"

Optional fitment
225/60R16 = 26.6" * good as snow tires and extended highway use for +mpg's
245/50R16 = 25.7"
245/45R17 = 25.7"
275/40R17 = 25.7"
315/35R17 = 25.7"
335/35R17 = 26.1" * drag only on an 11" wheel

[2000silvervette]

I've got a c5 coupe with 275/40/18 on back, I'd like to put some dot drag radials on the factory wheels, I've found some nitto 555 r in 285/35/18, will they go on and ride good, or are they not going to match the wheels. running a 13.0 now hoping to get in to the high 12s with good traction at launch, running stock run flats now, and I've looked a some factory size falkens, but would rather have the street legal drag tires.

[mrr23]

wil lbe about 1/2" shorter. will go on the wheel.

[2000silvervette]

Sounds like they'll work alright, I believe I can live with them being a little shorter, thanx for the info.

[Y2KPewterSS]

On my new CCW wheels I am planning to go with 18x10s up front and 18x11s out back. For the rear tires I am going to be using 295/35/18s which are 26.1" in diameter. I am considering 2 different sizes for the front, either 275/35/18 which is 25.6" or a 255/40/18 which is a 26".

My question is, if I use the 275s up front would the .5" diameter difference affect the ABS or anything else?

TIA
Preston

[mrr23]

.5" is iffy. most likely won't. do they make a 265/40-18 in the brand you are looking to get? it is 26.3" tall.

[Y2KPewterSS]

.5" is iffy. most likely won't. do they make a 265/40-18 in the brand you are looking to get? it is 26.3" tall.

Negative, its either the 255/40 or a 275/35. I could go with the 255/40s and only be off .1". Going that route would save me $60 as well, just not sure how the 255s would look

[doberman 152]

mrr23, were abouts in o-town i'm in kissimmee?

[mrr23]

i just moved to ocoee. so, about 30 minutes away.

[doberman 152]

i got friends there and APK

[mrr23]

i have two fellow club members in kissimmee as well.

[tinindian990]

So if you want to run radically different tire diameters front/rear can the PCM be programmed to compensate? What's the best software to do that?

[mrr23]

So if you want to run radically different tire diameters front/rear can the PCM be programmed to compensate? What's the best software to do that?

none that i'm aware of. all you can do is take the fuse out for your ABS, so it won't activate on you.

[tinindian990]

none that i'm aware of. all you can do is take the fuse out for your ABS, so it won't activate on you.

Ok thanks. At least there's a way to get around it.

[joker]

how do you feel about 295-35-18's all around ?