Steel Vs. Alloy Wheels (I Thought Steel Was Better?)


#1

I’m looking at different automakers websites on the internet. I notice the base model always comes with steel wheels (rims), and they always offer an upgrade to alloy wheels (usually an inch or 2 larger as well). My understanding is that the steel wheels are basically functionally better i.e. last longer, more durable for the long haul; and the alloy wheels are more prone to damage if you hit a big pothole, also more prone to pitting from road salt in the winter, but they “look nicer”. Is my understanding correct, or am I missing something? Is that the reason why people pay $700 - $1,500 more to get alloy wheels, just because they “look nicer”? Is there any logical reason for a cheapskate like me to pay extra for alloy wheels?

And WHY are wheels in general getting larger? Used to be almost all cars and light trucks had either 13", 14", or 15" wheels. Even my full size '92 Chevy pickup truck had 15" wheels. (Excepting the early Metros and the 88 - 93 Festivas which had 12" wheels). Nowadays even the smallest cars have 14" wheels with the option for 15" or even 16" alloys, and the big pickups seem to have 17" and 18" wheels and even larger. Is there a legitimate reason for the wheels getting larger, or is it a grand conspiracy to force everyone to buy larger (i.e. more expensive) tires? (Can you tell, I don’t trust the automakers propaganda)

Forgive me if this topic has already been covered ad nauseum and I somehow missed it.


#2

Lower unsprung weight improves handling and lower rotational mass improves response to acceleration.


#3

First of all, steel is an alloy. Everyone abbreviates Aluminum alloy OR Magnesium alloy incorrectly to just “alloy”. Sorry to be pedantic.

Yes, you are correct, steel is cheaper and stronger than “alloy”, but heavier, so you have more unsprung weight, which changes the suspension, not for the better. But I doubt 99% of the drivers would notice the difference.

And yes, the larger wheels with lower profile tires tend to be easily damaged.

Lower profile tires are totally (well almost totally) a marketing gimmick. Auto companies feel that that makes the car more “stylish”, like low visibility windows. I always buy the highest profile tire/wheel setups I can find on a new car. Although that is becoming more and more difficult to find. As is car radios that can be operated without a PhD in computers.


#4

First, there has been a move to eliminate asbestos in brake pads - and to achieve the same performance level, the brakes needed to get bigger. That also meant the rim diameters needed to get bigger. To keep the same tire diameter, the OEM’s moved to lower aspect ratios.

In trucks, they could go to a tire diameter that looked more in proportion to the rest of the truck (although, I think even dually trucks look a bit awkward relative to the tire size.

Second, lower aspect ratios resulted in improved handling - something car magazines can measure and appreciate. The fact that lower profile tires are more prone to pothole damage and don’t protect the wheel from that same damage is an unfortunate side effect.

But alloy wheels ARE better. They are generally lighter, especially if you consider the weight of the hub caps and/or wheel covers. So there are benefits in ride and handling. They are also better looking and allow for some styling to take place. And while they do corrode, the corrosion is less visible than rust.

So overall, alloy wheels are an upgrade.


#5

Capri: re brake size, that may be true and perhaps was a reason for the switch to somewhat larger wheels, 16-17 inch, but not for the very low profile ones.


#6

I like steel wheels with the proper trim but they can be downright ugly on a lot of vehicles. Alloy wheels are usually always better looking. The one steel wheel that’s my favorite is the GM rally wheel which was on a lot of earlier Corvettes, Nova’s and Camaro’s. I’ve used them on several different vehicles like the S-10, Silverado and Chevy full size vans and they always look good…with the proper trim of course.


#7

Of course, CapiRacer is correct on all counts, but I wanted to add a thought to this comment of his: And while they (alloy wheels) do corrode, the corrosion is less visible than rust.

Am I the only one who has noticed that a huge percentage of the steel wheels nowadays are coated with rust after just a few years? When walking through parking lots, I can’t help but notice that between the spokes of those abominable-looking plastic hubcaps, one can see rusted steel wheels on a great many of the low-rent cars parked there.

I don’t recall rusting of steel wheels to have been a problem years ago, and–in fact–none of my old cars with steel wheels ever had a rust problem, even after as long as 9 or 10 years, but I have observed that rusted steel wheels are now the norm in my area after perhaps only 3 or 4 years.

Is it possible that manufacturers are being less careful with the coating of steel wheels nowadays?


#8

VDC, I think you are correct. With (my opinion) the great majority of cars sold with “alloy” wheels, steel wheels are not given the manufacturing care they once did.


#9

IMHO steel is better. But alloy looks fancier, and that sells cars.

Pitting and corrosion was a problem with (my) alloy wheels many years ago, but the alloys used now, combined with improved casting technologies that virtually eliminate inclusions and occlusions as well as lack of homogeneity (“reverse gravity” casting is used almost exclusively now) AND the coatings used now have pretty much eliminated the problem for most manufacturers. I’m unaware of any that are still struggling with the problem.

As regards the weight, I thought alloy wheels were lighter too… until I looked up the weights of various wheels. Some are, some aren’t. The ones that are don’t look robust enough to survive our potholed roads here in NH.

On a given car, low aspect ratio tires improve handling, but the same assumption really can’t be made of new cars. Designers take the wheel/tire combinations into consideration as a part of the overall handling and ride they’re shooting for, and the suspension gets designed including the wheel/tire combination. It’s really only for style. As are the bigger wheels.


#10

a 17" alloy wheels is about 30% heavier than a 15" alloy wheel. Larger circumference. Does a 17" alloy wheel weigh more/ less than a 15" steel wheel? Don’t know.


#11

Am I the only one who, when car shopping, checked the replacement cost of tires for the wheel sizes on various trim levels? That future tire replacement cost factored into my buying choice.


#12

OP to answer short and sweet, yes steel is more durable, and alloys are bought mainly for looks. They DO make good looking and durable steel wheels but usually aftermarket.


#13

Am I the only one who, when car shopping, checked the replacement cost of tires for the wheel sizes on various trim levels? That future tire replacement cost factored into my buying choice.

Probably. I know I don’t. I rarely keep a car long enough to wear out a set of tires.

But seriously, you’re going to need tires, no matter what you buy, no matter what size or type. Is the difference in cost (at the extreme a few hundred dollars, probably much less) amortized over the lifetime of the tires–40,000 to 60,000 miles–really a deciding factor?


#14

In 60,000 miles a car that gets 30 mpg will go through about 2,000 gallons of gas. How does the cost of that compare to the replacement cost of tires?
It amazes me how people can dicker for weeks going from dealer to dealer trying to shave $500-$1000 off the price of a new car…and then totally shrug off mediocre gas mileage.

Also, don’t assume that the aluminum wheels are always lighter than steel wheels. The low strength of aluminum means everything has to be thicker in order to be strong enough.


#15

Well, you have a very valid point about the amortized cost. Had I felt I could afford to have bumped up to a 6-cyl for purchase price I wouldn’t have let the cost difference in future tire replacement have factored in. But, as it turns out, it is a good thing I choose the more affordable 4-cyl given how the costs have soared for the house structural repairs and renovation. Had I known the problems that would be found I would have dumped the dump or bulldozed it and started from scratch. Would have been easier and less expensive. Now house proud and cash poor. Thankful I have no mortgage and no car payments!!!


#16

Alloy wheels can be lighter, but they don’t have to be.


#17

It is way easier to style an aluminum wheel, you have so many options! As for wheel diameter, CapriRacer is spot on. Bigger brakes. Asbestos removal is one reason for bigger brakes but so is the far greater traction afforded by modern tires and the increased speed of modern engines. The kinetic energy grows the the speed squared. That means you need a bigger chunk of iron to absorb the heat of a 135 mph to 0 stop and bigger diameter to cool them off.

As for lower profile tires…if they weren’t lower profile, the diameter would get very large. Too large to fit some cars and the rotational moment of inertia would also get very large from the heavier, larger diameter tire.

Tire makers have done a fantastic job over the years of making low profile tires ride smoother AND give great handling.


#18

Here’s a good article comparing wheel sizes on a single car:

One alloy wheel type we don’t see much is stamped alloy, built like a steel wheel. The only one I know of was on the Honda CRX HF, friend had one, I had to take a magnet to it to convince myself he was right:


#19

Everything else being equal, a larger diameter wheel will provide a better ride. Especially on rougher roads. That’s part of the reason why wagons of yesteryear that travelled on rut filled dirt and rock strewn roads used large diameter wheels. Lighter wheels require less ummmph from the motor to get them spinning so that’s why performance car folks prefer light weight alloy wheels. Well, actually the reason is b/c race and rally pro-drivers use them for that reason, and we all like to pretend to be race car drivers … lol … seriously, it’s like when you see a group of bicycle riders riding down the street, they are all dressed up in those colorful uniforms pretending to be pro bicycle racers. Same idea. And no harm to have some fun doing some Walter Mitty pretending.

But if you are of the frugal persuasion, and don’t intend to do many road rallies in your econobox, the smaller diameter steel wheels are probably a better choice.

If you decide to go for the bigger diameter wheels for the better ride quality, check to see what a replacement set will cost before you make the final decision. It isn’t unusual for car owners having these big wheels to be handing over $1400 or more to replace a set of four gigantic tires.


#20

“Everything else being equal, a larger diameter wheel will provide a better ride.”

Nope. For a given tire diameter, the larger the wheel, the rougher the ride because of the lower tire profile. I guess you meant for a fixed profile, larger tire/wheels would give a better ride. I guess they would but one can’t substitute bigger tires in most cases.