PDA

View Full Version : Bigger wheels



nikgallagher
Wednesday 30th March 2005, 11:19
Aesthetics aside, are there any benefits to adding bigger diameter wheels to your car? Seems to be plenty of cons though: Usually unsprung mass is increased giving poorer ride quality, speedo goes out of calibration, acceleration is reduced, and suspension working space is reduced (rubbing etc.), not to mention increased tyre costs.

Bracer
Wednesday 30th March 2005, 11:32
Grip for one :eclipsee_

Which is something the T5's are lacking :mgshoot:

mraldonnelly
Wednesday 30th March 2005, 11:38
Aesthetics aside, are there any benefits to adding bigger diameter wheels to your car? Seems to be plenty of cons though: Usually unsprung mass is increased giving poorer ride quality, speedo goes out of calibration, acceleration is reduced, and suspension working space is reduced (rubbing etc.), not to mention increased tyre costs.

Hi Nik,

Diameter no, width yes. Unfortunately it isn't always possible to increase the width without increasing the diameter. I have just fitted new shape V70 wheels which are fitted with 225/45/17 tyres. This means that the diameter is about 3% bigger. Obviously my speedo wil misread (only slightly though) but they are not that accurate anyway.

I get very slight rubbing on full lock but it really is only slight. However, I think I am going to take them off and stick 'em on eBay. They look soooo much better than the original wheels and fill the arches quite nicely indeed but I would rather not have to worry about the rubbing however slight.

If I could fit 205/40/17 tyres then there'd be no problem but apparently these are too thin for the wheel :frown: .

Regards

Andy

nikgallagher
Wednesday 30th March 2005, 11:38
Increased grip would only come with widening the tyres though wouldn't it? I'm talking more about the diameter of the wheels.

mraldonnelly
Wednesday 30th March 2005, 11:59
Increased grip would only come with widening the tyres though wouldn't it? I'm talking more about the diameter of the wheels.

The benefit of a larger WHEEL diameter is that if you can fit a tyre which keeps the overall WHEEL + TYRE diameter the same then you have less sidewall thus less flexing of the sidewall under hard (or even mild) cornering.

For example, a 16" wheel with 205/50/16 tyres has an overall diameter of 611mm. A 17" wheel with 205/45/17 tyres has an overall diameter of 616mm. A ver minor difference but the difference in cornering will be greatly improved.

My new 17" wheels with 225/45/17 tyres has an overall diameter of 634mm. Still not a huge increase but more than I would like. If only I could get hold of 225/40/17 tyres then I'd have a near identical overall diameter but with greatly increased width. Unfortunately though I can't find 225's with a 40 profile anywhere which I guess means they will be very pricey.

Regards

Andy