rrc715

95 C2
Wheels MY02

Front 8/18 et50
225/40ZR18

Rear 10/18 et65
285/30ZR18

Current tires Sumitomos III
Previous tires Perrelli Rosso

shadow993

Exactly... Looks great and fills up the rear well nicely. When I ran a 265, it had too big of a gap.

TJ993

My Front tires are 235 ON 8 Inch Turbo OEM rims.

NYC993 suggested check Tire rack for sizing for a 7.5 Inch rim. Best to play it safe with the Family on board.

I wanted to try to reduce Pot Hole effect. I went 40 on the Rear height instead of recomended 35. My 4th set of rubber.

My Suspension is STIFF - Not sure 40 height made a difference.
Then wider in the front and rear for DE purposes - Just to experiment.
Learning Slip Angles and Fun stuff as a Newbie

E30M3

Ok here is my dilemma:

I would really like to put the widest tire in the back (285/30R18) but would also like to go with a set of Michelin Super Sports but the largest size they have is a 275/35 R18. How would the 275 look compared to a 285?

Thanks.

ilko

275/35 will be too tall. Get the Michelin PSS in OEM sizes and you'll have a great handling car.

E30M3

I really want a slightly wider than stock size tire in the rear because a 265 size tire just looks too "stretched" in my opinion..

E30M3

I compared a 265/35 R18 vs a 275/35 R18 and found the following results:


265/35 R18(stock size)

Section Width: 10.43 in 265.00 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 9 - 10.5 in
Overall Diameter: 25.30 in 642.70 mm
Sidewall Height: 3.65 in 92.75 mm
Radius: 12.65 in 321.35 mm
Circumference: 79.49 in 2,019.10 mm
Revs per Mile: 822.03/mi
Actual Speed: 62.14 mph 100.00 kph
Speed Variance: -
Diameter Variance: -

275/35 R18

Section Width: 10.83 in 275.00 mm
Rim Diameter: 18 in 457.2 mm
Rim Width Range: 9 - 11 in
Overall Diameter: 25.58 in 649.70 mm
Sidewall Height: 3.79 in 96.25 mm
Radius: 12.79 in 324.85 mm
Circumference: 80.36 in 2,041.09 mm
Revs per Mile: 813.18/mi
Actual Speed: 62.81 mph 101.09 kph
Speed Variance: 1.08% too slow.

red67vert

So we're talking 7mm taller?

E30M3

Yup..

NYC993

Either will be norrower than the rim. I'm running 275 on 11 inch rim so 265 on 10 is not really stretched.

Do you have C4? If you put larger diameter tire in the rear you will remove pre-load form the viscous coupling, if you care for such thing.

E30M3

Interesting..

Yes mine is a C4. What negative or adverse side effect would result, if any, from removing the preload from the V.C?

NYC993

No idea. In theory, slower transfer of torque to front wheels, in practice probably nothing.

95_993

Agree 100% with Ilko.

I am running OEM sizes of PSS on twists. Very balanced, no "stretching"

E30M3

Here is what I am referring to when I mean "Tire Stretch". This is a car in my shop now with a 265/35 R18 tire on a 18x10 Twist wheel..

red67vert

Yep, that's how they look. Does 275 make that much diff.?