Speedtoys

If I use a say, 35 profile tire in the rear, is there any reason why I shound/need/have to stay with a 35 up front?

Say:

285/35/18 rear (11" wheel)
245/45/10 front (8" wheel)

?

928mac

From what I have been told, no

z driver 88t

Always been my understanding that it's best to match the outer diameter as close as you can rather than the profile. For example, the outher diameter of a 245/45 16 on the rear is within 0.3 inches of 225/50 16 on the front. If I were to try a 245/50 16 on the rear it's almost an inch taller.
You can check the specs of most size combinations on Tire Rack's website.

anonymousagain

No.

Especially with wider rears, you'll want a lower profile than the fronts to keep "similar" diameter...but not required. eg, 'Vette's come from the factory with different size, profile and overall diameter.

No HTwo O

My 993 Turbo is 295/30/18 rear and 235/40/18 front. OEM was 285/30/18 and 225/40/18.

hacker-pschorr

My commute to work is mostly left hand turns so I actually have taller profile tires on the ride side of my cars.

No HTwo O

How do you get home?

hacker-pschorr

Very carefully.

No HTwo O

^How many shares of Packer stock did you buy this week?

T_MaX

I say, go make your day!

jon928se

For cars with ABS

1 You need to keep the same (ish) overall diameter both front and rear. Alternatively defined as keeping the sidewall height approx the same (if the rims are the same diameter)

2 You do know that the 35 or 45 means the height of the tyre (sidewall height if you like) is 35% or 45% or the width of the tyre.

35% of 285 = 99.75mm =3.9"
45% of 245 = 110.25mm = 4.33" = too big

a better option would be 245/40
40% of 245 = 98mm = 3.85" near enough to 3.9"

3 In the absence of any other consideration ideally you want to keep the diameter (2x sidewall height + wheel diam) about the same as the original wheels to make the speedo read correctly.

245/40/16 = 24.67" dia = original
285/30/18 = 24.72" dia = orig + 0.21%
245/35/18 = 24.74" dia = orig + 0.29%
245/40/18 = 26.67" dia = orig + 8.1%

PS corrected your typo 245/45/10 would cool on a Mini Cooper (original 1960's mini not BMW version)

Jerry Feather

In Reverse?

hacker-pschorr

danglerb

Could be an issue with ABS type stuff, but otherwise in what way do front and rear tires interact, pretty much none I can think of. Right and Left on the rear you have the differential or maybe a solid axle, so same diameter is required.

S4ordie

Not the experience Jwise and I have. We both run 17 inch wheels/tires on the front, 18 inch on the rear. The tires have almost identical OD. I run 255/295 (F/R) for an excellent ride and handling combination.