Do wheels actually make much of a difference?

[epts2008]

basically as my car stands at the moment it has 15" wheels running 195/65/15 m+s tyres that used to be used on the old 4x4 turbo sierra and I have a set of 17" alloys at work ready to be put on the tyres on these are 225/45/17 2 tyres are dunlop sp sport runflats and the other 2 are goodyear excellence I was planning on running the run flats on the back and the goodyears on the front my car is only the 1.4 16v model was just wondering would running these wheels and tyres actually give me that much of a noticeable handling improvement?
thanks

 

[DannyC87]

yes and no; the bigger wheels will be harder for the car to turn so acceleration will be slower (higher unsprung weight). But having less sidewall movement available due to smaller sidewalls should help the cornering abilities of the car a bit

 

[D.K]

The ride might feel a bit firmer due to the lower profile aswell

 

[Deleted member 19366]

If I was you mate I'd loose the runflats as they weigh twice the weight of a normal tyre and will also give you a harsher ride as there is no play in the side walls and will bring up alot of road noise. Also there is a possibility that the runflats can cause excessive wear on shocks springs and joints(because of their weight) as they are meant to be fitted to cars that have their suspension set up around these tyres.

 

[Ruddmeister]

If you want the handling to improve start with a pair of Anti-roll bars and a front strut brace

Wheels are going to be 90% style on your car 10% handling

Or save the money and put it towards a Cupra

 

[volvic]

run flats and normal tyres on the same car is NOT recommended(except for emergencies). thats not my opinion, its what tyre companies say

the run flats have much stiffer side walls and i imagine it will upset the handling of the car.

 

[Willie]

Yup start from scratch with the tyres and if you want better handling get ARB's upgraded or stiffer suspension

 

[LEE69]

I noticed a huge difference in handling/getting the power down going from 15" to 17" wheels on my old car, suffice to say i opted for 16" in the end as a compromise.

 

[lordgibbness]

For best handling you want wide rubber and a tyre profile between 50% and 35%. Bigger wheels won't make your car handle better, but just add weight.

 

[matt-drummer]

Larger diameter wheels may well weigh more but because the wheel is bigger the tyre sidewall will be smaller, therefore the tyre will be lighter (assuming a similar width). The overall wheel and tyre weight won't change much will it?

It seems that lots of people believe that increasing the wheel diameter somehow makes the outside diameter of the tyre bigger, it doesn't, the aspect ratio of the tyre is changed to keep the rolling radius as near to unchanged as possible.

I defy anyone to notice any acceleration changes due only to a different weight of wheel and tyre, a change in the rolling radius, yes but not an extra kg or two on a wheel.

Big fat low profile tyres may well be great on a circuit but on a bumpy back road more compliant tyres with slighter softer suspension can yield a faster easier to drive car. I found out in my rallying days that too stiffly sprung cars on very low profile tyres can feel very slow and nervous compared to something a little softer on roads similar to many of the smaller roads in this country.

Small sidewalls don't necessarily give the best handling, look at an F1 car for example!

Wider tyres give more grip to an extent but you also have to bear in mind that the smaller the patch of rubber in contact with the ground, the more pressure is exerted through the smaller contact area to the road surface thus aiding grip, very wide tyres behave badly on uneven road sufaces, sometimes narrower is better, look at a rally car set up for snow and ice conditions as an example.

 

[lordgibbness]

Unsprung weight can and does make quite a lot of difference in terms of handling. Yep, you don't want really low profile tyres as they are too stiff and again upsets the handling. Any lower than 35% is just for show in my opinion.

 

[LEE69]

Larger diameter wheels may well weigh more but because the wheel is bigger the tyre sidewall will be smaller, therefore the tyre will be lighter (assuming a similar width). The overall wheel and tyre weight won't change much will it?

It seems that lots of people believe that increasing the wheel diameter somehow makes the outside diameter of the tyre bigger, it doesn't, the aspect ratio of the tyre is changed to keep the rolling radius as near to unchanged as possible.

I defy anyone to notice any acceleration changes due only to a different weight of wheel and tyre, a change in the rolling radius, yes but not an extra kg or two on a wheel.

Big fat low profile tyres may well be great on a circuit but on a bumpy back road more compliant tyres with slighter softer suspension can yield a faster easier to drive car. I found out in my rallying days that too stiffly sprung cars on very low profile tyres can feel very slow and nervous compared to something a little softer on roads similar to many of the smaller roads in this country.

Small sidewalls don't necessarily give the best handling, look at an F1 car for example!

I noticed a huge difference in handling/getting the power down going from 15" to 17" wheels on my old car, suffice to say i opted for 16" in the end as a compromise.

Saves me typing it out again.

 

[epts2008]

right cheers guys thanks for the advice think i might get them run flats off soon then and put a couple of the excellences on them instead as i get the tyres for the price of a pack of biscuits so yeh ill change the run flats to normal. I've found that the change from 195/65/15 to 225/45/17 is exact same wheel diameter but obviously that extra bit of weight from the alloy will weigh it down slightly but will run them and see how it feels
cheers again guys