Steel vs. Aluminum

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Sep 27, 2003
Princeton, TX
I'm currently window shopping for some new wheels for my Ranger. I want to stick with a 15" (currently running 31x10.5R15 tires). My stock wheels are 15x7 aluminum. I'm thinking about going with a 15x8 or sticking with a 15x7.

What advantages/disadvantages are there in steel vs. aluminum. Steel are cheaper, and if dented can be hammered out. Aluminum reduces the un-sprung weight, but can break.

What would work out better and give the best ride/performance.


PS - Anyone know what the backspacing is on a stock 15x7 Ford Ranger wheel?
A 8 inch rim would be a better fit to that sized tire I would call the 7" too narrow.
On the steel vs. aluminum a cubic inch of each and yes the aluminum is lighter but in the world of OEM wheels the steels are often lighter due to the shear quantity of aluminum they use. Might not be the case for your truck but many factory aluminum wheels use a lot of aluminum and weight more than a basic steel wheel of the same size. Aftermart aluminums can weight less due to better care in casting and tighter quality control making thinner castings or forgings safer.
DJ pretty well covered it. It's personal prefernece vs bank account decision. You won't save much weight without spending big $$ on alloy wheels.

Have you considered something like these?

I don;t have any experiance with that company, I just used them as an example of that type of steel wheel.

One last thing to think about: If you like to do serious off-roading, (i.e. Moab), the steel wheels can provide more give than alloy wheels. Alloys can have small stress cracks form while you are on the trail that can leave you with a flat.

Just a thought.
He is right 8" rim would look better with that size tire But I don't like it when rims/tires stick out from the side of the vehicle which might happen with an 8" rim.

The stock steel 15x7 wheels on my '04 2wd Ranger were the same weight as the aftermarket 15x7 Aluminum Ultras I replaced them with. The aftermarket steel wheels will likely be heavier. My rims cost $60 a piece at America's Tire, that's cheap for Alum. The truck looks at least $240 better too
Actually a lot better than that. I got the same rim for the spare too. BTW I put on 30x9.50s for tires

Only thing I like steel on are hard core off road vehicles. I have broken 2 aluminum wheels on my 4x4 and I mean broken. On the other hand I have bent 1 steel rim as well. Tradeoffs, both can get messed up pretty good but steel holds up a little longer. I've seen steel rims I like for around $50 each, some less and that's chrome
Any vehicle can benefit from less unsprung weight and rotating mass. Unless your rockcrawling and the momentum of the heavier combo can help some.
I seriously think that with 31x10.5R15 (what I run on my 4Runner), the difference in unsprung weight (as a %) would be tiny, if present at all.

I've lugged those tyres around the back yard (cheaper to plant potatoes in them than to pay the disposal cost), and they aren't light.

And as others have said...a steel wheel is a collection of stampings/rollings welded into a structure, while an alloy is basically a monolith.
Some time ago I went to an automotive aluminum conference where we were discussing the state of affairs with aluminum in automotive use. A big part of the automotive business for using aluminum was in alloy wheels.

They listed the pros and cons of using aluminum over steel, and there wasn't much benefit to using aluminum. The main reason people were buying aluminum wheels was for looks. The only other benefit is unsprung weight... but the small benefit of having unsprung weight comes with a hefty price tag.

If you think the extra cost will pay for itself in fuel savings because they're lighter, it's not gonna happen during the car's lifetime. Over 100K, you'll save maybe $30 in fuel costs from the weight savings.

For the most part, compared with steel wheels, aluminum

- Is considerably more expensive
- Less pothole resistant
- More difficult to mount tires
- Harder to keep looking good
Thanks everyone.

This is what I wanted to hear. I have been looking at some steel wheels in 15x8, but I need to make sure that I can get the correct back spacing so they don't stick out past the fender flares. It's hard to beat about $50.00 per wheel vs. $100.00 and over for alloy.

It sounds like I should be fine with steel

There are more benefits than mileage to unsprung weight.

Your car handles better (less weight on the axle, spring etc.)
Your brakes stop you faster (less rotational mass)
Your car accerates quicker (seen tests done back to back on drag strips)

Have you ever seen a sports car with 18x11" steel wheels. That would be a heavy freakin wheel. I've held forged Vette rims that are so light, lighter than the 15x7s on my truck.

Being harder to mount is not my problem, it's the tire shops so I don't care. They don't charge more for alum vs steel.

The pothole consideration is for low pro tires or enormous potholes. But a pothole that will crack aluminum will probably also bend a steel rim.

Harder to keep looking good is true to some degree. But if you don't take care of your steel rims they will rust over time, even chrome.

And remember I paid $60 each for my aluminum rims. I sold my stock steel rims for $200 on ebay. Mine may not be lighter but certainly look better.
As far as denting rims. Generally this is a problem for low profile tires or off-roading. You'd have to hit a pretty big pothole to dent a truck rim with a 75 series tire.
On a Ranger with 15x8's you generally want a 3.75" backspace, although a 31x10.50 isn't a huge tire. OE Ranger 15x7's have a +12mm offset, whatever that means for backspace. There is much info on Rangers including tires and wheels on the forums at
Aluminum rims might lose air a little faster too. Not a problem if you're a maintenance freak and keep that checked up on.
Centerlines are excellent wheels (lightweight and strong forgings) and I think they're reasonably priced. Most of the CL wheels I've seen are primarily marketed toward the truck/SUV segment so you should be able to find plenty of choices there for your Ranger.

Originally posted by JohnnyO:
... +12mm offset, whatever that means for backspace...

Offset is the distance from the mounting plane of the wheel to the plane equidistant to the inner and outer flanges (offset from "center"). Backspacing is the distance between the mounting plane and the plane of the inside rim of the wheel.
Aftermarket steel wheels are generally thinner and weaker than factory rims. A tire shop talked me out of buying his rims when he saw my truck with a heavy camper on it and didnt want the liability. He showed me how thin the metal was on the aftermarket rims compared to stock. Unsprung wieght should be less, maybe comparable to aluminum.

Originally posted by T-Keith:
As far as denting rims. Generally this is a problem for low profile tires or off-roading. You'd have to hit a pretty big pothole to dent a truck rim with a 75 series tire.

It's not the holes, it's scraping against hard surfaces and having the wheel catch on them. Or sliding sideways into things.

I bought some cheap steelies for my 4Runner for this very reason since the factory alloys started getting scuffed up after only a couple of times off the road.

I run the factory wheels in the summer and the steel ones in the winter or when I wheel it...
With steel wheels you don't have to worry about the tire mounting guys scratching your rims. Unless the appearance is important to you I'd go with steel on a daily driver truck.
Not sure about truck, but for compact car my OEM steel will be 21lb each 14", and OEM alum will be 15lb each 15". You have to get to 17" to get back to steel's weight.

I think it is more of an inertia than unspung weight issue, since mass is mostly on the outter edge, it has more effect than saving 20lb total on a car. I heard somewhere that flywheel weight is 50x the effect on vehicle mass, if you divide that by the gear ratio it will be like 20lb * 50 / 4.3 = 232lb total saving.

Not much for a truck, but a lot for a small car.
I think the stock alum. Ranger wheels look good and whould be able to handle oversize tires. I have seen stock 7" Dodge fullsize truck wheels with 265 75R-16 tires on them. That's a pretty big tire that fills up the Dodge wheelwells nicely. My suggestion is to save your money and use what you already have.
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