It seems nuts because it likely is. Most forums taking up the subject put the number at anywhere from a 1.5 lbs to 3.0 lbs equivalent savings for every 1.0 lbs of wheel/tire weight saved. What affects this number the most is the radius at which the weight savings is realized. Reducing 4 lbs of tire weight would be superior to reducing 4 lbs of wheel weight because the tire is located at a greater radius from the wheel center and therefore has a higher torque associated with it. There is a savings to be had, especially on more mundane cars, it's just not a 780 lbs savings (likely closer to <100 lbs). Typically, most explore this ground tracking a car, but there are also daily driver benefits to be had with improved turning, stopping, and ride quality.

 

Ugh, too much math on a Sunday morning...LOL

 

GRM figured this out a long time ago.

 

Yeah, it is funny, there is so much money spent on lightweight wheels and tires and there is very little practical evidence to support doing so. I admit being a blind subscriber to this theory as well, but am reconsidering it now after reading another test similar to the one above. In it, they found considerable differences in lab testing but very little difference in track results. In their testing, the gravity cast 5zigen averaged faster lap times than forged monoblock/lighter Rays/Volk, forged/lighter SSR, partially forged/lighter Enkei, and gravity cast AXIS wheels. All wheels/tires tested were 18 x 8.5 wheels fitted with brand new tires on an EVO IX. http://www.superstreetonline.com/how...ce-wheel-test/

 

 

Here is an article, but it takes LARGE changes in weight and size to result in a 0-60 or 1/4 mile change of 0.1s or 0.2s. https://www.caranddriver.com/feature...d-tires-tested

 

Thanks! Yeah been a car guy for a long time on multiple forums. Based on your other thread about trying to get into the 11s in the quarter mile, I think your money is better spent on wheels that allow you to have the WIDEST and cheapest tires. So likely something like an 18x9.5 or 18x10 if you want dual duty street and strip.

If you're gonna be pure performance on the strip, look into buying some Weld Racing wheels or similar in a 17x[as wide as can fit] and get some drag slicks.

 

You'll need a pretty special set of 17's to fit our rear brakes.

I raced bicycles and I can say empirically, lighter wheels make a big difference when they are as big as a typical 700C wheel, but lighter tires AND lighter rims made the biggest difference. I had "race day only" wheels and wheels I used to train because the race day tires were super light and super expensive (for the time). It was vastly easier to accelerate with the lighter wheels. We used to say an ounce off the wheel was like a pound off the frame, but it isn't really that dramatic.

Automotive applications are dramatically different than bicycling because road cars have suspension and road bikes do not. Also, GRM's testing assumed the suspension settings should remain the same regardless of weight, which isn't necessarily true. Lighter wheels need less damping and can be more compliant than heavier wheels that need substantial more damping to prevent over travel (in both directions) and oscillation. Testing for all of that would be nearly impossible as it would require a whole lot more effort than most can afford in a comparison like this, but they might have found a significant improvement in grip had this been part of the testing parameters.

All that said, if it's drag racing, wheel weight isn't going to be the big factor here. Getting the car to hook is where all you effort should be, and lighter wheels aren't going make a huge difference like getting the suspension right will.

 

 

There are a few guys that run 285 and 295 rears. I have 285's on my stock wheels with no issues.

 

 

https://www.clublexus.com/forums/is-...eet-azure.html

This is a good place to start answering that question.

 

I'm on my stock wheels and haven't had any problems. I'll go check, but I'm pretty sure there's still plenty of room.