Different Tire sizes

[Evil Result]

I noticed that on the McLaren F1 the size of the front tires is smaller than the rear, is there a reason for this.... like improved handeling, easier steering(has no ps), body design(low hood surface for aerodynamics), or Weight.

and

If you did have smaller tires sizes would it still work with AWD/4x4?

[drdisque]

handling, most RWD sports cars have wider rear tires than front tires. and no, you definitely wouldn't want to do that with FWD

[Evil Result]

Sry..forgot to describe what tire dementions i was talking about, i ment to refer to the diameter of the tire and not the width.

i would think that in a AWD situation, with the front tires being of a smaller diameter you could adjust the front differential ratio to keep drive shaft speeds the same.

[Alastor187]

Originally Posted by Evil Result

I noticed that on the McLaren F1 the size of the front tires is smaller than the rear, is there a reason for this.... like improved handeling, easier steering(has no ps), body design(low hood surface for aerodynamics), or Weight.

and

If you did have smaller tires sizes would it still work with AWD/4x4?

You should provide the source of your information, so we can reply with more than just assumptions. I am guessing that since the rear tires are wider than the fronts, a larger diameter tire with a lower profile can be used to produce approximately the same overall wheel diameter as the fronts.

For example:

Fronts:

17 – 45 – 295 = Overall diameter of 27.45 in.

Rear:

18 – 35 -335 = Overall diameter of 27.23 in.


The overall ODs are not exactly the same but close enough to make a point. Also, a more subtle point is using different tires effects the balance of the vehicle. A lower profile tire will generally have a higher corning stiffness, and wider tires can generate more grip than a narrow tire.

Values came from tire calculator at:

http://www.1010tires.com/TireSizeCalculator.asp

[Evil Result]

McLaren F1 tire sizes

Front: 235/45R17

Rear: 315/45R17

http://www.mclarencars.com/content/s.../f1/whlinf.htm

http://www.conceptcarz.com/folder/ve...ehicleTypeID=0

http://www.supercars.net/cars/1997@$McLaren@$F1g.html

http://www.fantasycars.com/derek/cars/f1.html

[Rufe]

My guess is that the rear tires are larger due to the engine's power.
With half the HP, the wheels would probably be the same size.
The fronts are large enough to get the job done, and the rear tires
needed more contact patch to get the traction down.

No, you don't want to mix sizes (diameters) on AWD, or 4x4.

[Alastor187]

There is a significant overall difference in front and rear wheel diameters. Not sure but it may also have something to do with the underbody aerodynamics. The lower front and higher rear may help to generate the ground effect.