what's the ideal wheel weight?

[I_luv_HP&trq]

I currently have 18x8 chrome wheels and i weighed one the other night when i was rotating them. it was a whopping 50 lbs with a 245 tire on it. that just seems like a lot to me. will getting a lighter set of wheels do enough to make a difference? better gas mileage, or quicker accleration??
I'm tired of riding on these gangsta bling bling wheels and want to get a better set IF i can sell mine. what is everyone's opinion?

[lowflyn]

Chrome is heavy. Non-chrome is lighter.

[MarkuzLS1]

Get polished aluminum wheels. They're lighter and they look better than chrome.

[WhiteStang99]

I think chrome looks better, but if I was at all concerned with performance I would most definitely go with polished.

[SpectorV]

my chrome wheels and tires are about 7.5 lbs heavier than my old stock 15's... dont sound like alot I know... but every rotating lb = 10 dead weight lbs, so by upping your wheel weights by 7x4, or 28lbs... thats like adding 280lbs to the car

[WhiteStang99]

^ I was gonna say that, but I wasn't positive how many rotating lbs = how many dead weight lbs.

[jimmy_beaner]

doesn't it matter where the weight in the rim is distributed? I believe it does, but maybe that's just for rotational inertia, which is rather related here. Like, if you have a very heavy center vs. a very heavy outer rim.

[Monkey]

reduce unspring weight and reduce 1/4mi times. Increase mpg. Increase handling. Increase acceleration.

Wheels are pretty important. Putting lighter wheels on your car will do all of the above. Basically (like Spector said) 1lb rotating mass = 10lb = 1hp. 10lb rotating mass is 0.1sec in the 1/4.

You decide how important weight is

[tedness]

Quote: Originally Posted by SpectorV my chrome wheels and tires are about 7.5 lbs heavier than my old stock 15's... dont sound like alot I know... but every rotating lb = 10 dead weight lbs, so by upping your wheel weights by 7x4, or 28lbs... thats like adding 280lbs to the car

you are waaayyy off my friend.

http://www.miracerros.com/mustang/ww.htm

according to this, the wheels alone are almost 10lbs heavier. even if you got the AFS brands, you're still looking at 8 or 9lbs heavier.

overall chrome 17x9's w/ tires are generally 14-16lbs heavier than stock 15x7 wheels/tires. so you figure an ungodly amount of extra rotational mass

[1998Stang]

Quote: Originally Posted by Monkey Wheels are pretty important. Putting lighter wheels on your car will do all of the above. Basically (like Spector said) 1lb rotating mass = 10lb = 1hp. 10lb rotating mass is 0.1sec in the 1/4.

This topic is particularly interesting to me, and is how I found this site in the first place! I also read the article on Bill Wenger's site, and have to assume that 40 pounds or so would be my stock wheel and tire weight.

After looking at the weights of wheels and tires on TireRack for example, it's apparent that a 10 pound increase per wheel would not be uncommon if you went to 18's. (Some of the wheels alone are over 30 pounds :bigeyes

That would be 40 extra pounds of rotating mass = 400 pounds, but would it really mean a decrease of 40hp? I wouldn't want to take that big of a horsepower hit!


All best, and still learning,
Joe

[SpectorV]

i put my 95 cobra Rs (oem ford) on the scale and they were 7.5 lbs heavier than my stock 15s. I have no idea about my current wheels, Same specs so most likly same weight within a pound or so~

7.5 per wheel comes to 30lbs, or the same as 300lbs of dead weight. Thats two tenths slower in the quarter~, but the traction you gain may make the difference to actually improve your times depending on what you were doing before.

[1998Stang]

OK . . . but does anyone know how much horsepower is lost by upgrading to larger ( = heavier) wheels/tires?


Steeda says their "Ultra-Lite" wheels are 22-24 pounds for 18's and "about 1.5 pounds less than that" for 17's. So if my stock wheels/tires are 40 lbs, and I get their wheels, that's ~5lbs per wheel or 20 more lbs rotating mass = 200 lbs dead weight. That would be like riding around 24/7 with a 200 lb back-seat driver, right? ( well, at least she'd be quiet!)

Since I only have the V-6, I don't want to waste any horsepower at all.

Steeda also says their aluminum driveshaft is 6 lbs lighter than stock. Does this count the same way as wheel/tire weights because it's rotating mass?

Am I worrying too much? Sorry for the newbie questions, but I gotta learn!



Thanks,
Joe

[Brent]

You don't lsoe actual horsepower you lose time off your quarter mile due to it taking more effort to move your car with the added weight.

[SpectorV]

if you wanted a comparison it takes about 120 lbs of dead weight to equal 10 hp~ that is a very rough estimate so just use it as an example~

[jimmy_beaner]

I'm sure it matters where the weight is distributed on the rim.... a heavier outer edge of rim, like something with a design that has large amounts of material near the far outer rim, would effectively take more energy to get spinning. I know it sounds trivial, but it really isn't.

[whipster24]

Quote: Originally Posted by jimmy_beaner I'm sure it matters where the weight is distributed on the rim.... a heavier outer edge of rim, like something with a design that has large amounts of material near the far outer rim, would effectively take more energy to get spinning. I know it sounds trivial, but it really isn't.

yep, the further you move the mass from the axis of rotation, the more inertia an object will have. That's why a lot of flywheels have more weight towards the outside.



The "ideal" wheel weight is zero But being that it's not possible, get some draglites

[1998Stang]

I stumbled across this link via an article suggested by AZ2Kvert:


http://www.mazda6tech.com/index.php?...d=16&Itemid=32


There is a great Excel spreadsheet within this article and it shows just how difficult is is to improve wheel appearance without degrading its performance!

I weighed one of my stock 15" polished alloy wheels yesterday at 40lbs. Using the weight of the tire (from TireRack.com) as 26 lbs, then my wheels weigh 14lbs!

Where can I find a great looking 18" wheel that weighs that much or less?


All best,
Joe