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How much weight savings with alum vs. steel wheels?

Mastiff

Mastiff

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I really kind of prefer steel, but weight does matter to some extent. I noticed my 35" Swampers on steel K30 wheels feel way heavier than my BFG MTs on aluminum. Might be the rubber? It's all I can do to lift the BFG spare up onto the mount on the back of my Jeep, don't know if I could do the swamper to the same height and control it well enough. Anyway, are we talking 5 pounds out of 100+ total for the tire/wheel package, or what?

I looked up the tire weight for what I have:
Swamper rubber = 76#
BFG Rubber = 66#
 
Don't know about the weight savings on aluminum vs. steel wheels, never ran aluminum, but its not a fair comparison with a swamper on one and bfg on the other.

Ive got a set of 35" bfgs on steel wheels that I can carry with one arm and a set of 36" (yes I know they are an inch taller) radial tls on steel wheels that kick my butt every time I have to dismount or mount them on the vehicle.
 
doing tires and wheels for years tires and rims will surprise you .

seen them go both ways for weight .

pi what you like and need it for and run it .
 
I was checking out pitbull rockers... 84# for the 315/75R16. The steel wheels I was looking at are 37#. Total weight: 121 pounds. :eek1:

EDIT: Dug up specs on an aluminum wheel same size. 23#. So in this particular case, 14 pounds of savings. Not insignificant I guess.
 
In general terms an AL. part will weigh a bit more than half of what it's steel counter part does.

AL is 1/3 the weight of steel, however usually more material is needed when using AL so that's why the bit more than half rule.

Just to give you an idea about the different weights of tires, one of our 42" Goodyear sticky race tires on the wheel is like 132#, one of our 37" hard compound Goodyear desert tires was like 130# on the same wheel. The 37" tires had some serious rubber in them for going through the desert.
 
Rotational mass makes a much larger difference than static mass.....this means that 56 lbs. (14 lbs. x 4 wheels) sitting in the bed of truck would not be noticed when doing acceleration or braking tests, but 14 lbs. lighter mass for each rotating wheel would be. As a rough estimation you could assume that adding weight to the tires and wheels is equivalent to adding 10 times that much weight to the bed of the truck. So if you added a tire and wheel combo to the truck that was 14 lbs. heavier per corner for 56 lbs. total rotational mass, that would be about the same as adding 500-600 lbs. to the bed of the truck.

That is why you hear about people gun drilling axleshafts and having lightened cranks on drag cars. They may only be removing a couple lbs. of material but it's the same as taking 20 lbs. out of the body of the car.
 
6.2Blazer said:
Rotational mass makes a much larger difference than static mass.....this means that 56 lbs. (14 lbs. x 4 wheels) sitting in the bed of truck would not be noticed when doing acceleration or braking tests, but 14 lbs. lighter mass for each rotating wheel would be. As a rough estimation you could assume that adding weight to the tires and wheels is equivalent to adding 10 times that much weight to the bed of the truck. So if you added a tire and wheel combo to the truck that was 14 lbs. heavier per corner for 56 lbs. total rotational mass, that would be about the same as adding 500-600 lbs. to the bed of the truck.

That is why you hear about people gun drilling axleshafts and having lightened cranks on drag cars. They may only be removing a couple lbs. of material but it's the same as taking 20 lbs. out of the body of the car.
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I'm not sure what you me when you say "same as". You mean in terms of strain on axle shafts? Resistance to acceleration and braking? It seems it would all depend how fast the mass is spinning in the first place, and how much you care about hot rodding.
 
He means same as because the heavier rotating mass takes more effort to make move. Similar to how a heavier vehicle will take more effort to move.

It's like leaving your big box of recovery gear at home when you're just driving around town. No need to carry a couple hundred pounds of stuff in the back sucking up performance and mpg because they're just acting as ballast.

Same deal with aluminum wheels vs steel wheels. Heavier wheels and tires will require more oomph to move.
 
Mastiff said:
I'm not sure what you me when you say "same as". You mean in terms of strain on axle shafts? Resistance to acceleration and braking? It seems it would all depend how fast the mass is spinning in the first place, and how much you care about hot rodding.
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I was talking about acceleration and braking, but it also effects strain on drivetrain components. The biggest point is that there is a huge difference between rotating mass (wheel and tire weight) and for example a sand bag of the same weight sitting in the bed of the truck.

Take a stock K5 and perform a 0-60 mph acceleration and a 60-0 mph braking test. Add a 56 lb. sand bag in the passenger seat and repeat the tests. You won't be able to accurately measure the difference in the acceleration or braking.

Now remove the sand bag and bolt on a set of wheels, like a steel beadlock, that weigh 14 lbs. heavier each (a total of 56 lbs.) than the stock ones. The truck will now have noticeably slower acceleration and increased braking distance.

Now put the stock wheels back on but put 560 lbs. of sand bags inside the K5. You will see about the same slower acceleration and increased braking distance as just the 56 lb. heavier wheels caused.

Yes, how fast the components spin does make a difference. That is why decreasing the weight of engine components like the crank, which spin at thousands of RPM, makes more of a difference than decreasing the weight of axle shafts, wheels, etc... that only spin at hundreds of RPMs.
 
I wasn't doubting anything, just making sure we were clear. I'm not too worried about braking since the 1-ton brakes are overkill anyway. Acceleration is cool, but not my priority - so it's a consideration but not decisive. Being able to get the spare in/out of the truck is pretty important though. :D I have no idea how people wrangle 40" tires that could weight 140 pounds with the wheel.
 
Mastiff said:
I have no idea how people wrangle 40" tires that could weight 140 pounds with the wheel.
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Man up. I can load and unload the spare in the race car somewhat easily and it mounts at torso height. But I'm 6'2" and 210 lbs, I also can only do it two to three times before I hurt myself.

You can do it maybe just not real pretty like.
 
I know the difference between 9.75 x 16.5 Aluminum slots and OEM-style steel wheels is 10#...30 vs 40. I don't feel that is significant enough to worry. I can say I hve never seen any difference one way or another on any rig I've run in the last 40 years. The tires are a much bigger factor
 
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