Front Tyre Sizes - The Unofficial BMW M5 Messageboard (m5board.com)

IvanDias · 21st October 2001, 13:26

I see on the E39 site, that several people have taken the huge 275 tyres from the rear, added Dinan or other 10mm ish spacers and bolted them on the front.

This apparently helps reduce some of the cars understeer tendancy.

If I got another pair of the 9" rears from the back of my M5 3.6 1990, could I do a similar thing?
I have not tried it or measured yet with one of my tyres on the car already, this is just a "thinks aloud". Has anyone done it already ?

So - 9" Rears 255/17 to replace 235/17 on the front.

1. Would they be OK if no spacers were used?

2. Would the wheel steering clearances be OK with spacers if required?

3. If you can use 265 at the rear instead of 255, could I use 265 on the front?

4. Any problems or issues I have not thought about?

Ta,

Ivan.

IvanDias · 25th October 2001, 20:44

No replies?

All of you out there with 235 fronts?

Ok, so what can you and can`t you put on the rear?

Several people say 265 don`t rub, but 275 need wheelarch mods.

Who out there has is an expert on this. 17" preferred, but advice on 18 and up is wecome.

Nene · 25th October 2001, 23:32

Ivan-
Dinan supposedly runs 255 on the front of their car with their wheels (special offset). As for the rear, they run 275. I haven't tried it, but it must be possible. Personally, I'm gonna go with the 19" Hamann wheels once I save up. They are 8.5" in the front and 10" in the rear. I haven't explored all the tire options yet, but I know a 235/265 combo is very good.

Hope this helps,
Nene

C_O_L · 26th October 2001, 22:31

Adding larger front tyre sizes will not cure an understeer problem! all it will do is unbalance the car and make it oversteer!! what's worse!
BMW didn't spend millions of deutchmarks on developing the M5 so people could just improve by swapping rears for fronts!!!!
The price of 3.8 suspension should give you some clue as to where the 3.6 understeer problem lies!

As for understeer on the V8 many manufacturers are now building idiot proof handing into their cars! it's a lot safer to have a understeerer than any oversteerer! especially for the uninitiated!!!!!!!!!!!!!!