top6491

Guys, are BBS RS-GTs (24lbs for a 20x8.5) , and other really lightweight wheels really worth the premium price? I mean, can you notice the difference in normal to spirited driving (not track stuff). Would 3-4 more lbs make much difference? And does the tire you use also make just as much of a difference?

freed0m

I have the BBS RS-GT 20" wrapped in a nice set of Pirelli PZero tires on my M6 at the moment and am very happy with them.

EuroCarFan

Even if you don't track your car, lighter wheels will reduce parasitic power loss to the ground because they have less unsprung weight and reduced rotational mass. Lighter wheels also help in braking and will be easier on your suspension components.

andy545

correct !

I went from 172's to 167's and lost 15lbs from each corner - very noticeable in all respects.

flyingpuck

Less unsprung weight is ALWAYS a good thing!!

EuroCarFan

There's a 15lb difference between the two wheels???

heezy545i

Lighter is always better, but there are diminishing returns and after a point, you're simply paying for style and brand.

It's up to you whether it's worth it, but a few pound difference will likely not make much of a difference for regular driving. And you mentioned it yourself, but tires themselves can differ around 2 pounds depending on the brand.

20s look great on e60s, but lightweight 20s are a bit of an oxymoron. If you're all about performance and handling, 20s would probably not be the first choice.

JetBlack5OC

I wouldn't say that. You correct about handling, 20's are not the first choice. If your tracking a car I wouldn't even go 19's. But who is really tracking a big E60 in the first place.

But when you consider a sub-20lbs 20inch 360 Forged wheel vs a ~30lbs 20inch Rad. Your looking at 40lbs+ less weight, less rotational mass, and unsprung weight. You will definitely feel the difference.

I did not know 360 Forged offers a "race prep" option on their wheels, until a few days ago. Their 20inch wheels are already light in the first place, but with the race prep option it cuts an additional 4lbs. Their 20inch wheels range 20-22lbs, minus another 4lbs, thats just crazy light for a 20inch wheel.

heezy545i

I concur that lighter is better, just that if there isn't a huge discrepancy in weights, than it shouldn't make a difference, especially if that weight savings will be nullified by tire choice. Now a 10lb difference per corner is huge and makes for a totally different scenario.

Personally, I would try to stay clear of 30+ lbs wheels in the first place, especially if you're already going to be paying a premium. On the other hand, if you're going to be saving money, then a slightly heavier wheel might be okay.

Just to point it out, a forged wheel does not always equal a lightweight wheel. In terms of HREs, other than the competition series, these are heavy forged wheels. So if you were buying these rims, it would primarily be for style and brand.

I haven't looked much into it, but depending on how the wheel is manufactured, a heavier wheel may actually hold up to abuse much better. I'm sure Porsche knows what they're doing, but the rear wheels on the 997 GT3 are ~30lbs. There's no doubt they could have gone with a lighter wheel, but there are probably good reasons behind their choice.

Again, I'd prefer a lighter wheel, but for 545/550s these are ~4000lb cars, so saving weight might not make much of a difference. If 1lb of unsprung weight equals roughly 4 lbs of sprung weight, then a 5lb savings per corner would equal ~80lbs of sprung weight. That seems like a pretty significant amount, but consider that running a 1/4 tank of gas saves about 80-90lbs compared to a full tank of gas. Well for myself, I didn't notice a difference in driving dynamics when driving with a 1/4 tank versus a full tank, so I might not notice a difference with slightly lighter or heavier wheels. Of course, I am simplifying things as unsprung mass and rotational mass is different, but in the end a slight weight savings might not be worth the added cost on a heavy car like the e60.

edit: added a few thoughts.

Oh and ECF was gracious enough to let me drive his car. His car felt plenty quick with those "heavy" rads.

JetBlack5OC

Yeah, I was so surprised the other day when EuroCarFan told me his Radenergie's weigh 30lbs. I would have thought such expensive wheels would weigh less.