Do lighter wheels really make a difference?
Discussion
There are three factors to consider:
Given the maths of the above you will be much better off looking harder at the weight of the tyre before looking at the weight of the wheel.
- Reducing dead weight
- Reducing the flywheel effect
- reducing unsprung weight
Given the maths of the above you will be much better off looking harder at the weight of the tyre before looking at the weight of the wheel.
Anything thast reduces the unsprung mass is generally a good thing - the springs and dampers can control less weight more easily and accurately. But the unsprung mass also incudes the hubs, brakes, suspension arms etc. as well as the wheel and tyres so, in percentage terms, sometimes a lighter wheel can have a very small overall effect. As stated here already, it is the wheel/tyre mass combination that is important - a larger diameter wheel will have more 'metal' but less (lower profile) tyre so the difference with a smaller diameter wheel but higher profile tyre can be negligible. However, for equal size wheels then a lighter alloy (providing it is actually lighter) than steel wheel will bring some advantages in the suspension/ride stakes and also in providing more control, and therefore grip, on bumpy corners. As for noticeably improved turn in, I doubt that this is a result of lighter wheels, this is much more likely to be down to tyre type.
However, a larger diameter wheel with lower profile tyre does stiffen up the suspension somewhat as there is generally less flex in the tyre sidewall - and the tyre sidewall does contribute to the suspension. This can have the effect of making the suspension too stiff (even if the wheel/tyre mass is significantly less) - not usually a problem for grip on smooth dry roads (but can make the ride a bit too crashy and firm) but can reduce grip significantly on bumpy wet roads which obviously reduces performance.
In other words, it's not a simple straightforward matter and what is good for one car is not necessarily good for another.
However, a larger diameter wheel with lower profile tyre does stiffen up the suspension somewhat as there is generally less flex in the tyre sidewall - and the tyre sidewall does contribute to the suspension. This can have the effect of making the suspension too stiff (even if the wheel/tyre mass is significantly less) - not usually a problem for grip on smooth dry roads (but can make the ride a bit too crashy and firm) but can reduce grip significantly on bumpy wet roads which obviously reduces performance.
In other words, it's not a simple straightforward matter and what is good for one car is not necessarily good for another.
Edited by Garvin on Saturday 2nd January 10:45
Rollcage said:
B'stard Child said:
Rollcage said:
are lighter than the equivalent steel option - a lot has to do with the design of the alloy.
For really significant weight differences you need forged alloy wheels, as opposed to cast.
Some early Carlton GSIs had a forged alloy on them, and some had the same design ,but cast. the difference in weight was very noticeable, but for cost reasons they didnt appear on many cars.
My favorite subject - all the carlton GSi's fitted with the slabby 5 spoke wheels were forged alloys however there were two versions and one is heavier but not by much - later 10 spokes were cast and a lot heavierFor really significant weight differences you need forged alloy wheels, as opposed to cast.
Some early Carlton GSIs had a forged alloy on them, and some had the same design ,but cast. the difference in weight was very noticeable, but for cost reasons they didnt appear on many cars.
Incidently the 15' steel wheels were lighter than even the 5 spoke forged alloys
Unlike some on here!
Never owned a Manta but it's on the list for one day
B'stard Child said:
Rollcage said:
B'stard Child said:
Rollcage said:
are lighter than the equivalent steel option - a lot has to do with the design of the alloy.
For really significant weight differences you need forged alloy wheels, as opposed to cast.
Some early Carlton GSIs had a forged alloy on them, and some had the same design ,but cast. the difference in weight was very noticeable, but for cost reasons they didnt appear on many cars.
My favorite subject - all the carlton GSi's fitted with the slabby 5 spoke wheels were forged alloys however there were two versions and one is heavier but not by much - later 10 spokes were cast and a lot heavierFor really significant weight differences you need forged alloy wheels, as opposed to cast.
Some early Carlton GSIs had a forged alloy on them, and some had the same design ,but cast. the difference in weight was very noticeable, but for cost reasons they didnt appear on many cars.
Incidently the 15' steel wheels were lighter than even the 5 spoke forged alloys
Unlike some on here!
Never owned a Manta but it's on the list for one day
Rollcage said:
I remember your name from my Autobahnstormer/RMOC/OMOC days Ian! Good to see someone flying the flag. If I could have all my Mantas/Monzas from the mid/late 90's on now, I could probably afford an LC! I think I had four Monza GSEs and a couple of Mantas (including a straight six one) at one point.
I went backwards car wise - started with Senators and Carltons and then an LC but was drawn to a Monza and now have a few (some projects) and a 72 Commodore which is definatly a long term projectBut what the hell they are all six bangers and such a sweet engine
I'm not the only one flying the flag so hopefully there will always be a few Monzas about - I don't think mine wins many fans from the concours brigade now mind
I’ve replaced the factory wheels with a set of very light forged aftermarket wheels made of special strong aviation-grade alloy (by SMW), and I am very pleased with the resulting performance. I saved over 35% as compared with the original cast wheels – and I really feel the difference, especially at cornering. I also noticed that the gas mileage did improve somewhat (though not more than 5% - 8%). So this investment payback will be within a couple of more years, in addition to the enjoyment of better handling.
Marks_Lisnanskis said:
I’ve replaced the factory wheels with a set of very light forged aftermarket wheels made of special strong aviation-grade alloy (by SMW), and I am very pleased with the resulting performance. I saved over 35% as compared with the original cast wheels – and I really feel the difference, especially at cornering. I also noticed that the gas mileage did improve somewhat (though not more than 5% - 8%). So this investment payback will be within a couple of more years, in addition to the enjoyment of better handling.
Good to know. Unfortunately, though I sold the car eight years ago.Gassing Station | General Gassing | Top of Page | What's New | My Stuff