Wider wheels or wider track
Discussion
I saw a Vauxhall Tigra yesterday and at first i thought he had wide wheels then i realised they where the correct size wheels but where sticking out more so he either had spacers on or the wheels had come off a different model.
It got me thinking, if car manufacturers get the wheel size correct taking into account grip, ecomomy, mileage, cost, etc,then why do people put wider wheels on?.
If its for looks thats fine but if it to give the car more grip are they not compromising something else?.
I borrowed my sons car on 2 occasions, firstly when it had 205 on and then again after he had fitted 225 (with correct wheels). The first time i managed 45mpg, the second time it only did 37mpg.
My question is. If a cars track was 72 inches and you increased it by 3.6 inches that being 5% would your cornering speed be increased without losing on mpg as apposed to if you increased your tyre size from say 185 to 195, that being about 5%.
If you increased your tyre size you might lose mpg as in my sons case.
If you increase the track of a vehicle have you lowered the center of gravity and so improved its handling.
Last question.
If your car had 185x60x14 wheels would a good swop be 175x50(or 55)x15 then fit a 20mm spacer, would you then end up with a similar amount of grip but with better economy?.
>> Edited by slowly slowly on Wednesday 29th March 18:10
It got me thinking, if car manufacturers get the wheel size correct taking into account grip, ecomomy, mileage, cost, etc,then why do people put wider wheels on?.
If its for looks thats fine but if it to give the car more grip are they not compromising something else?.
I borrowed my sons car on 2 occasions, firstly when it had 205 on and then again after he had fitted 225 (with correct wheels). The first time i managed 45mpg, the second time it only did 37mpg.
My question is. If a cars track was 72 inches and you increased it by 3.6 inches that being 5% would your cornering speed be increased without losing on mpg as apposed to if you increased your tyre size from say 185 to 195, that being about 5%.
If you increased your tyre size you might lose mpg as in my sons case.
If you increase the track of a vehicle have you lowered the center of gravity and so improved its handling.
Last question.
If your car had 185x60x14 wheels would a good swop be 175x50(or 55)x15 then fit a 20mm spacer, would you then end up with a similar amount of grip but with better economy?.
>> Edited by slowly slowly on Wednesday 29th March 18:10
Wider tyres can mean more grip, but as there's a greater contact area, it can also mean they are more difficult to get up to operating temperature.
Wheel spacers I really don't like! Unless the offset of the wheels is changed to keep the track the same (and that goes for wider wheels too) then spacers will alter the whole geometry of the suspension and could easily lead to unpleasant handling vices.
Because they increase the track, they will also increase the load on wheel bearings, wheel studs/bolts, etc. and cause premature and unexpected failure.
In either case going too wide will end up with the tyres fouling bodywork and reducing steering lock.
Wheel spacers I really don't like! Unless the offset of the wheels is changed to keep the track the same (and that goes for wider wheels too) then spacers will alter the whole geometry of the suspension and could easily lead to unpleasant handling vices.
Because they increase the track, they will also increase the load on wheel bearings, wheel studs/bolts, etc. and cause premature and unexpected failure.
In either case going too wide will end up with the tyres fouling bodywork and reducing steering lock.
Spacing the wheels out means there will be less weight transfer in cornering so fractionally better grip. It also means the steering offsets will be wrong so you will get more kick-back , torque steer and tramlining and the wheel bearings will wear out faster.
Fitting wider tyres without changing the offset means you will get slightly more rolling resistance and drag (so worse economy), the steering will feel slightly more direct (less deflection in the tyre) and you will get slightly more grip before the tyre starts to slide, but you will get less feedback through the steering telling you that the tyre is about to slide, and once it has started to slide the grip will fall off more suddenly.
Fitting wider tyres without changing the offset means you will get slightly more rolling resistance and drag (so worse economy), the steering will feel slightly more direct (less deflection in the tyre) and you will get slightly more grip before the tyre starts to slide, but you will get less feedback through the steering telling you that the tyre is about to slide, and once it has started to slide the grip will fall off more suddenly.
TripleS said:
Pardon my ignorance, but could someone just explain what 'tramlining' means?
I have assumed it is where a car is sensitive to small longitudinal ridges in a road surface, making it wander off course slightly.
Best wishes all,
Dave.
You assumed correctly. You notice it most when drving on roads where you get a seem where they have been dug up and repaired. The car tends to pull towards and then follow the seem.
>> Edited by ckyuk on Thursday 30th March 15:01
ckyuk said:
Pardon my ignorance, but could someone just explain what 'tramlining' means?
I have assumed it is where a car is sensitive to small longitudinal ridges in a road surface, making it wander off course slightly.
Best wishes all,
Dave.
You assumed correctly. You notice it most when drving on roads where you get a seem where they have been dug up and repaired. The car tends to pull towards and then follow the seem.
>> Edited by ckyuk on Thursday 30th March 15:01
OK thanks for that. Obviously a bit of a nuisance but not as bad as crossing real tram lines....on a push bike....in wet weather! Talk about getting stuck in a groove...
Best wishes all,
Dave.
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