Tire Height Question???

[PhunkDJti]

if i were to change the height of the wheel, would it be better to make it shorter or taller. ive heard alot of opinions on the effects, but nothing concrete.

i have 17x8.5 wheels for a 96 318ti. (so if i got the recommended size, the tires would be streatched as hell) and i cant decide if i should get 235/40's or 225/45's?
the 235/40's-shorter 225/45- taller

[Dirty_Tool]

check the "brakes wheels and suspension" section at http://bmwtips.com Theres some good info there inc a tire size calculator.

[camnipotent]

I'd go with 235/40-17. It's a wider stance and the shorter sidewall will give you a little better handling. Also, they look better.

[PhunkDJti]

those are the exact reasons i want to get the 235's, but im concerned with the wheel well lip, even with the lip rolled, it looks like its gonna be extremely close, so i dont know

[camnipotent]

Are you worried about rubbing? I have 18's on my 1998 323is and they never rub. They might if I have the car lowered and go over a bump or something, but as of now, I've been perfect.

[dutchbmw]

What's the original seize?

[camnipotent]

The factory original tires for 15" wheels are 205/60.

[dutchbmw]

The original height will be 24.685 inches.

1) With the 235/40 17 tyres the height is 24.402 inches.
2) And with 225/45 17 tyres it is 24.972 inches.

Conclusion: Option 1) has a deviation from 1.15% --> When driving 100 km/h the real speed is 98.85 km/h. The mileage becomes a little more negative. The topspeed decreases because of the width.

Option 2) has a deviation of 1.16% to the other side. Driving 100 km/h is in real 101.16 km/h. The mileage becomes a little more positive (In comparison with option 1). The topspeed is better than with option 1 tyres. Also not unimportant is the more comfortable ride!

Go for option 2.

[Eggrolled211]

I have 225zr17 with 45series...all around it lowered and doesn't rub yet unless I hit a bump at hard turns! Even these 225 are cuttin it close....235's hmmmm definately potential for rubbing IF lowered...just a reference for ya. 40 to 45 series will look great and awesome handling BUT the ride is rough, you can feel everything on the road....whelps can't have both gotta sacrifice one or the other?