Wheels & Tires

[Old smart]

First, I have no problem with the NA, '08, 9-spokers. But I am a little antsy about the front 155/60R-15s in view of ancedotal evidence of copious understeer. Of late now**, I know that there is some-but-negligible difference in wheel offsets between NA '08 fronts and rears. And I know that an OEM 175/55R-15 (a NA rear) will clear the '08 front fender arch, brake disc, and wheelwell. So, I may be inclined to outfit my car with specified, 9-spoke 175s on the front-end also, knowing that the tires to fit are currently available in the US.

**Tx to "Stevilution."

[mfoster]

I've been thinking about doing the same. Only concern I have is the rims on the front are 1 inch narrower (4.5 front versus 5.5 rear)

[Gortok]

Ok...so you go and find some 195's or 205's for the rear...right?

[Old smart]

Originally Posted by mfoster

I've been thinking about doing the same. Only concern I have is the rims on the front are 1 inch narrower (4.5 front versus 5.5 rear)

The idea is to use rear 5.5J-15 rims on the front, with its 175/55R tire. You will have the same rim/tire combination front-and-back like most every other car. Can't do it by just putting the wider tire on the narrower rim.

"Ok...so you go and find some 195's or 205's for the rear...right?"

Nope, 175/55 front-and-back. Otherwise you re-slew the car back toward understeer, but just it beginning at a higher speed. The idea is to knock-down excessive understeer without putting too much rubber on the road.

[Gortok]

So, if you wanna use the same wheel, front and rear...What IS the story with different offsets. I know what offset is, I just wanna know what the stock wheels are...and Why...

[DTB73]

The car is probably engineered that way to counteract the rear-weight bias in order to prevent oversteer (which is much harder for most drivers to control than understeer), although I'd imagine all the electronics should keep things under control. If you go bigger in front, you might also want to go bigger out back too. I wonder what the Brabus has?

[Karl Roth]

Remember the moose test issues in i think 98
"learning from your mistakes is a sign of inteligence learning from others mistakes is genius"...
sounds good let me know how it works for you
karl

[Old smart]

Originally Posted by Gortok

So, if you wanna use the same wheel, front and rear...What IS the story with different offsets. I know what offset is, I just wanna know what the stock wheels are...and Why...

I don't know why, but the front offset is 23.5mm and the rear 22.0mm for a NA 451.

[Old smart]

Originally Posted by DTB73

The car is probably engineered that way to counteract the rear-weight bias in order to prevent oversteer (which is much harder for most drivers to control than understeer), although I'd imagine all the electronics should keep things under control. If you go bigger in front, you might also want to go bigger out back too. I wonder what the Brabus has?

It is as likely that the larger rear tire size is to bear the heavier rear end weight as it is to push understeer to the front. Brabus is 175/50R-16 front and 225/35R-17 rear, more for show than to put that whopping 98PS on the road.

[Gortok]

Originally Posted by fishrdnc

the front offset is 23.5mm and the rear 22.0mm for a NA 451.

Thanks for that

;)