Dave DC

Does bigger rim size mean more speed or less? Or are those 18, 19 and 20 inch rims only for looks?

TLMugen

My take on your question is: when you say speed, I assume you mean acceleration; top speed probably isn’t an issue and I assume that you’ll keep the overall tire diameter the same as stock.
You’ll probably experience slower acceleration with the very large size wheels you mention because since more of the wheel’s weight is further out from the center, it’ll take a lot more torque to overcome the wheel’s increased rotational inertia to get it turning. You can mitigate this by getting the lightest wheel possible but of course that comes at an increase in cost. Braking may also be affected for the same reason, bigger brakes are a good idea. Heavier wheels also mean more unsprung weight which you want to reduce whenever possible partly because the car’s handling will be affected.
Take into account that the aforementioned items may be experienced only if you drive hard, probably under “normal” street driving circumstances, you may not notice much degradation in performance.
On the plus side, the bigger wheels look nicer on a properly set up car (the car should be lowered when you talk about wheels that large unless you want the “4x4” look). When it comes to “bling-bling”, probably no mod has a bigger effect than putting 18s, 19s or 20s on your car.
Overall I guess people go for the bigger rims mostly for looks which is of course a totally legitimate reason.
These points focussed on the performance and aesthetics of Plus-2, -3 or -4 wheel upgrades; keep in mind that another major aspect that will be affected is the car’s ride.

Ultimately do whatever floats your boat!

My 2¢, spend wisely!

goldendragon576

stick with the 18's or 19's. Stay away from 20's, not only does it not look right with the TL's but you'll run into rubbing problems.
TLMugen pretty much has it all covered, I'll second his post!

r10apple

Without getting into detailed physics (since I dropped that class anyway--but I understand the math and concept just can't show my work!) increasing the diameter of the wheel physically causes a decrease in acceleration. However, that can be offset somewhat by lightening the wheel that has been upgraded. Lightweight or heavy wheels will probably make more of a difference in acceleration on this car than the size of the wheel itself...

Dave DC

Excellent posts, guys--thanks! I'm thinking I'll stick with stock 16" rims and drop the car an inch. I like the look of larger rims, but not into bling bling.

Drew982TL

Wait....I got kinda lost in this understanding... I put 18 inch racing hart C5's on my car for one night(Friends rims) and the overall diameter was a little smaller than my stock rim and tire. and those wheels are by far lighter than my 2002 TL-S 17's. Your saying my acceleration was faster because of this?

Ianbiz3

what type of rims are these?

shimbo519

Trafficstar DTMs i believe.....very hot rims

unlemming

Not necessarily! Even though the wheel is lighter overall, the rotational inertia may be (and probably is) greater. It’s got to do with how far the weight is from the center of the wheel (by a factor of radius squared). There’s a lot of factors that factor into it, of course, but that’s the basics. So if you got a 17" that was lighter than your OEM 17", it would be easier to get it rolling..whether or not you could notice/measure the difference.. I wouldn't hold my breathe

CJITTY

Just get some OEM 17" wheels and tires and call it a day. I think those TYPE S wheels look good. I had mine chromed!

Drew982TL

I have the oem 17's. Mine have scratches on them, want to get them polished to the point where they look chrome. i dont like how they are 6.5 wide, handling is my focus, 18 by 8's do the trick