SC400-V8

iTrader: (1)

Right now my SC has 16X7.5" 7 spoke chrome alloy like found on the first generation GS/aristo. Next year, Im thinking I want to upgrade to these REALLY nice 18X8" 5 spoke chrome alloy, they come on the 2004 SC430s... you can see them on ebay right now. Should I notice any performance loss due to the bigger wheels? What If i get smaller tires so as not to change the overall diamater of the wheel itself?

BTW, Im not sure if the 18" wheels weigh more than the 16s....

Buttercup

The bigger the rim is usually always heavier than a smaller rim. The width counts too. Not only will the wheel be heavier, but the tire will be too because there needs to be more rubber to withstand the weight because there isn't enough air in the tire. Accleration wouldn't decrease so much, but it will. Steering response would be faster, grip most likely go higher.

Neo

iTrader: (3)

If you are talking about power, then you will lose some performance since you are going to heavier wheels, especially these stock wheels. As for your comment about the tire size and diameter, yes try and retain the stock diameter so it does not throw off anything on your car.

Baby ///M3

I recently upgraded from 16' chrome 1st Gen. GS3 16x7.5 wheels to GS400 17x8 wheels.

However, I did the wheel swap during my transmission so I can't really tell if there's any performance loss or not.

One thing I do know is that when I had the 16' rims, I could burn the tire rubbers if I just step on the gas a little harder. With the 17' Michelin Pilot Sport tires, I can no longer spin the rear tires from a stop.

Jon

Wald GS

iTrader: (1)

My car has had 19's for the past 8 months. When I had stock 16's the acceleration was much easier. WIth 19's there is lag when you floor it compared to 16's...

Lvangundy

Read what this educated man has to say.

Three page forum discussion.

http://www.lextreme.com/forum/viewtopic.php?t=460

Brandon@TR

In general plus sizing is a performance improvement for the vehicle. You will want to try and find a wheel with a reasonable weight and 19 inch is where the plus sizing of the wheel starts to reduce rather then improve the performance of the vehicle.

"One thing I do know is that when I had the 16' rims, I could burn the tire rubbers if I just step on the gas a little harder. With the 17' Michelin Pilot Sport tires, I can no longer spin the rear tires from a stop."

I think this is due to better traction rather then reduced power. You can time yourself in a 1/4 to be sure. Also, the performance benefits of plus sizing are seen in cornering and steering response and to a lesser degree straight line acceleration and braking. I noticed an improvement in every category when I moved to 18 inch from 17 inch stock.

Plus Concept

Buttercup

But sometimes wouldn't too much traction and razor sharp handling become no fun? What I mean is that 20 inch rims need thin tires and it won't distort much so you won't be able to throttle steer. Plus there is little or no warning when you reach the limit of grip.