Rear Tires

[J.P]

Bit of a numpty question, but is there any other reason why the width of the rear tyres is so big - I have followed a few Porsche's and am always amazed at this point.
I can understand about the need for wide tyres and power delivery, but I have owned M3's and a Tuscan, and the rears come nowhere near as wide.
Is it more to do with the engine config i.e at the rear, and therefore there is a neccessity to have wide tyres for extra lateral grip due to the potential of tail happy driving.

Just always wondered thats all..

James..

Appols - can't seem to spell tyres - doh..

Edited by J.P on Wednesday 16th August 12:35

[domster]

A lot of it is to do with weight distribution, I think. The fat rear tyres help support the heavy rear mass, (up to 70/30 on a 911) as well as contain it when that mass starts to want to step out sideways.

[sinly]

Don't know about why, but certainly noticed when come to buy some new boots for the rear...not only size, but specific N rating...and been advised not to mix front/rear brands, which means Pilot sports and not so cheap especially as just the spare/winter set

[johnfm]

Dom's on the mark - rear weight bias, though its much more 60/40 than 70/30!!

Edited by domster on Wednesday 16th August 14:00

[Andrew D]

Nah, it's to look cool, that's all!

You're correct, it's to do with the weight. The contact patch has to deliver the load of both the engine drive and the inertia of the rear end to the ground.

[sidicks]

johnfm said:

Dom's on the mark - rear weight bias, though its much more 60/40 than 70/30!!

I'm guessing my weight in the driver's seat helps to get closer to 50:50 ??!!

[domster]

johnfm said:

Dom's on the mark - rear weight bias, though its much more 60/40 than 70/30!!

Agreed, but would love to know distribution of a 930... they must be close to 70/30!!!

[nbetts]

and whilst we are on the subject of rear tyres - I must say that the Porsche 911 (996 & 997) are the least satisfying cars I have ever owned for leaving a number 11 tread mark when being a bit of a hooligan....

What I mean is with all that traction, when you do get them to break traction it is a most unpleasent experience and the car really fights the spin. The wheel thumps around in the arch and the whole car shudders....

Trouble is it looks so nice and relaxed on the TV...

[fieldl]

295 profile rears are

[Andrew D]

nbetts said:

and whilst we are on the subject of rear tyres - I must say that the Porsche 911 (996 & 997) are the least satisfying cars I have ever owned for leaving a number 11 tread mark when being a bit of a hooligan....

It's probably the car LEAST suited to leaving rubber, what with all the weight over the wheels to stop them spinning.

Z4M Coupe, that's what you want for 11's! Loads of power, no weight over the wheels whatsoever!