It is generally understood that cars handle better when unsprung weight is reduced. Unsprung weight is the combined weight of the tyre, wheel & suspension. While it is difficult to reduce the weight of the suspension on your car, you can easily reduce the unsprung weight of the wheel & tyre. This can have a noticeable effect on how the car feels as you drive over bumps (notably off-road). The lower the weight, the easier the suspension can follow the terrain and the less disruption it will cause to the car. This is particularly noticeable on a VW Beetle as the car, suspension and wheel/tyre were lightweight from the start. Adding larger wheels & tyres, and beefing up the suspension can more than double the unsprung weight, & reduce the effectiveness of the suspension.
You can benefit greatly by choosing wheels & tyres wisely. A standard VW wheel weighs 12lbs, and a 165R15 tyre weighs 17lbs, total 29lbs. In contrast a typical buggy 8×15 star wheel weighs 21lbs, plus a 48lb Yokohama 31×10.5R15 tyre, total 69lbs! That is 40lbs more, or over twice the weight of the standard set. This has a definate negative effect on the suspensions ability to work well.
If you still want a 31″ tall tyre, you could choose a lighter one, such as an Armstrong at 40lbs, and combine it with a 10lb Centreline wheel for a total of 50lbs. This saves 19lbs per wheel/tyre combination. Besides being easier on the buggy, a 19lb change at each rear wheel is something you can actually feel when you drive it. In addition, due to the increased rotational inertia, the car will accelerate & brake quicker. If you want to reduce even more, go to a 30×9.50R15 or a 235/75R15 instead and drop the combined weight to as low as 40lbs. Next time you’re looking for tyres or wheels, check the weight before you buy. If the brochure doesn’t list the weight, take a set of bathroom scales with you. You will find an amazing weight range.
