need new tires. should i stay with same size?

[540doug]

98 540i with m-sport rims . the tires are currently front 245 35 18 and rear 265 35 18. should i keep the same sizes. i was wondering if i could put someting with a little more sidewall loke a 40 series or 45. new england roads are not that fun. would a taller side wall fit?

[Jim@tirerack]

The only way to do a taller tie is to change the wheels to 17".

[nowbimmin]

holy misdirected information. You could have almost any tire size that you want (only limited to manufacturer).
Have a look at the tirerack.com website. You can choose what tire size you want.
I haven't found it yet, but this site should have a tire size calculator.
c'mon now Jim
sounds like you're trying to sell this guy some wheels that he doesn't need

[danfreek]

If you're increasing your sidewall size on your tyres without changing the rim size, then your rolling radius will be larger, and that effectively alters your final drive ratio. Your speedo will also be very innacurate.

To increase sidewall, you need smaller tyres.

But in answer to the OP's question, yes, increasing your sidewall will effectively soften the suspension. Ride will improve, handling will not be as good (less responsive).

[Jim@tirerack]

Sure you can pick any size you want. I answered what he would need to do to keep the car correct. You can't just pick a size because you want something taller. You would change the gear ratio, speedometer and odometer and they would probably rub.

[98M3_4]

Biggest issue would be proper fitment without rubbing

[98M3_4]

holy misdirected information. You could have almost any tire size that you want (only limited to manufacturer).
Have a look at the tirerack.com website. You can choose what tire size you want.
I haven't found it yet, but this site should have a tire size calculator.
c'mon now Jim
sounds like you're trying to sell this guy some wheels that he doesn't need

C'mon now

[nowbimmin]

I'm wondering if he could get away with a 255/40 up front and a 275/40 in the back. I beleive that is the way it would go if you were trying to atleast stay as close as possible to the same dimensions. But that is a pretty fat tire combo as is. It should effectively soften up the ride if possible. If anyone knows of a tire calculator we could use that. And then do some research to figure out how fat of a tire he could stuff without rubbing.

[Jim@tirerack]

Anything wider that the 265/35R18 is probably going to rub on the fender. The M5 has the fender lips rolled so they can run the 275/35R18. If you go with a taller tireyou are also going to have some rubbing issues as well as the other problems I stated.

[BimmerDawg]

the tires are currently front 245 35 18 and rear 265 35 18. should i keep the same sizes. i was wondering if i could put someting with a little more sidewall loke a 40 series or 45. new england roads are not that fun. would a taller side wall fit?

The only way to do a taller tie is to change the wheels to 17".

OE for that car was a 235/40 and 265/35...the 245/35 is WAY too short.

Run a 245/40 and 275/35/18 and all will be right in the world.

You're welcome!

[Jim@tirerack]

I agree but be careful with the 275/35R18 in the rear. They will hit on most cars without the fender lips rolled.