Another Wheel Thread

Since I've recently bought a few sets of wheels, I thought I'd post the differences. Pics in a minute, but the weights were interesting.

Compomotive TS-17s 17x9 10.6Kg, 17x8 10.1Kg
328 OEM pre-ABS 16x8 11Kg, 17x7 10.5Kg
308 OEM Speedline 16x7 7.4KG

I didn't have a 308 16x8, nor any unshod Superformance ones, but perhaps someone can chime in.

I was surprised by the lightness of the 308 wheel, and the heaviness of the 328 wheel, and pleasantly surprised by the Compo's.

 

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Where did you get the compo's? Is that center cap graphic a sticker?
Interesting weight savings of 7+lbs/wheel with the OEM's. 28Lbs is a lot of rotating/un-sprung weight.

 

Your comparison is a little unfair since it's a 7" wide 308 wheel vs an 8" wide 328 wheel, but (with some hand-waving to account for that) your result matches roughly what we've seen before = the 308 wheel is about 30% Magnesium + 70% Aluminum alloy while the 328 wheel is 100% Aluminum alloy.

 

the earlier the wheel, the more mg content hence lighter..

they made the wheels more durable on the later models

 

...and cheaper...

ciao

 

Good data! I weighed my OEM 16" wheels with tires, and subtracted the published weight of the tires, to get

308 16x7" front 15.4 lbs = 7.0 kg
308 16x8" rear 15.2 lbs = 6.9 kg !!

The mounting boss, or hub face, is thinner on the 8" wheel, perhaps accounting for the lighter weight. Of course, that's assuming that the Michelin published tire weights for their Pilot A/S3 were accurate.

I also measured the set of BBS E50 wheels similarly, wheel+tire then subtracting the weights of the Continental DW tires. The 16x7 and 16x8 BBS E50s were 15.0 lbs each, or 6.8 kg. They have a magnesium centre with aluminum barrels.
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I have a ton of loose wheels...

I suppose I will pile them in the truck and get some info for you...

 

I weighed the 7" 328 wheel as well!

 

And the result was?

 

Just got them off FChat! Not cheap, though, but the previous custodian kept them in brand new condition, and they're a credit to him. The centre caps look like standard resin ones - haven't had a close look yet. I expected them to be heavier, but was surprised at how light they were. I race a Lotus, so unsprung mass is very important, but I don't track the 308 - this was an aesthetic decision, not a performance one.

 

See post #1, but there's a typo; it's not 17x7, it's 16x7 - 10.5 Kg

 

If published tire weights can be believed and if my bathroom scale is accurate (every morning I think it reads too high!), the KN/Superformance reproductions weigh:
Front: 38.5 lbs total - 20 lbs. tire = 18.5 lbs = 8.4kg
Rear: 43 lbs total - 22 lbs. tire = 21 lbs. = 9.5kg

I don't know what a trashed TRX tire weighs, but the wheel and tire together were 39 lbs. So on average the KNs were pretty much a weight neutral swap. Rotating inertia might be a whole 'nuther thing.
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That sounds lighter than I would have expected. I wonder if Superformance publishes the weights?