Can someone tell me, on a rear wheel drive vehicle, what are the cons of wider rear wheels? Does it make steering more difficult?

 

This is a non-MINI question ... as you said ... right?

Do mean just wheels or tires/wheels?

I have
Front: 8.5"J x 19" - 235/35 ZR19
Rear: 10"J x 19" - 265/35 ZR19

Its pretty obvious the rears are bigger than the front. RWD, mid-engined. I see absolutely no cons to this design. In fact some others cars are much more radical OEM as in up to 305s in the rear.

Steering more difficult? Not from what I can tell. In fact, the car "just turns" ... no drama, no excitement ... its just handles ... OEM.

I'm not sure what your looking for. Maybe if the engine was in the front it would make a difference? Mid-engined is balanced just right.

 

On rear engine drag vehicles you often see super wide tires for grip, but the vehicles only go straight, so I was wondering if they then don't turn as well or what the cons are to the wide tire.

 

If the rear tires get too wide compared to the front, or more specifically if the rear has too much grip compared to the front, the car will tend to understreer at the limit. A lot of OEMs do this because it is much safer for the vast majority of drivers, plus people think it looks cool.

On a rear or mid engine car, or really even a front engine car if it has a rear weight bias, the rear tires will probably need to be wider than the fronts so that the lateral grip levels are relatively equal to the front.

Scott
90SM

 

Understeer, that's what I was thinking. So how does one know how wide is too wide? Is it just trial and error?

 

Pretty much. Just as someplace to start, if the car has a rear weight bias, you might try going two sizes wider in the rear than the front (ie 205 front, 225 rear). Many 80's 911s used those sizes from the factory.

For the record, tire width is just one of many ways to change grip at one end of the car relative to the other.

Scott
90SM

 

im running 245/35/19 and 275/35/19's on my G and it's not "too wide."
even have the stillen swaybars set at med up front and med on the rear
and still get plenty of controllable oversteer on demand.

and these are on S03's.

 

A wide flat tire can also be a handful in wet, slippery conditions-especially with a live axle rear like on a Mustang GT- Actually Mustangs will track man hole covers and other things on the surface. It is goo for getting the power down but it also offer a larger,flatter surface for plaining so if you go extra wide you got to watch the throttle when it's wet.