Almost since the dawn of the 4X4 debate has raged about whether steel or alloy rims are better for your 4X4. Here we get Mark Allen to look at the pros and cons of each.
The steel versus alloy rim debate has been going on since… well, since rims stepped up from being made from timber (pub trivia: the bicycle wheel was the first to go from wooden spokes to steel, or wire spokes – steel wheels for vehicles didn’t appear until the 1920s). Round the campsite, leaning on bull bars, while sipping at the bar, the debate has raged on as to whether steel really can be hammered back into shape, or if an alloy rim is weaker or lighter than steel.
Wheel and tyre basics
Let’s have a crack at setting the record straight, bust a few myths and share a few real-life experiences. First, let’s make sure we’re all on the same page when it comes to talking about wheels, tyres and rims:
- The tyre is the black rubber bit;
- The rim is the hard steel or alloy bit that the rubber bit is fitted to;
- A wheel is a rim and tyre fitted together;
- A steel rim is made from, er, steel and is rolled and pressed into shape then welded together;
- Alloy rims are a mixture of aluminium, nickel, magnesium and a few other metals depending on brand and quality. Cast alloy rims are generally speaking lower quality and cost and are often weaker too. There are gravity cast rims (generally dodgy aftermarket cheapies) and pressure cast rims (generally more costly, stronger and the type supplied by most original equipment manufacturers as well as some quality aftermarket manufacturers). Forged alloy rims are the bees’ knees of the highest strength, lowest weight and unfortunately, highest cost; and
- Mag rims which can be anything from a generic term for an alloy rim to an early version of constructing aftermarket rims from magnesium mixed with other metals.
What does the law say about wheel rims?
Regardless of which type of rim you purchase, you must ensure they are the correct size for your vehicle – width and diameter – as per the handbook, as well as ensuring any legal changes don’t foul guards, brakes or other components.
Load ratings are essential to take note of; some cheap aftermarket rims are either not rated or rated unsuitably low to allow your 4X4 to be packed to the gunwales for your dream trip. Any accident you may have with unrated rims will probably void your insurance too, so don’t chance it.
Cheap, non-rated or non-approve rims have no place on our roads. Don’t risk them just to save a few bucks. Your life, your family’s life, as well as mine, are more important than riding on dangerous rims.
A critical aspect many overlook are the wheel nuts. Generally, the wheel nuts used on a steel rim are not suitable for use on an alloy rim, and vice versa. If you regularly swap rims, you’ll need two sets of nuts.
Let’s talk about wheel numbers
Trawling the Interweb for a set of aftermarket rims? You need to know what all the numbers and dimensions stand for before dishing out your hard-earned. Let’s use a 16 x 8 5/150 -25 rim as an example.
- 16 = diameter in inches;
- 8 = width in inches;
- 5/150 = 5 is the number of holes in the rim for the studs/nuts, while 150 is the PCD (pitch circle diameter) in millimetres (the large hole in the centre) which sits over / on the hub; and
- -25 = is the offset in millimetres outwards from zero which widens wheel track (distance from left to right wheel centerlines), noting it’s illegal to alter the track by more than 50mm. Rim offset can be either zero, negative or positive. The offset is measured from the face of the hub mounting surface to the centerline of the rim.
There will also be a load rating stamped onto the rim, which is the maximum load each rim can carry. If you undergo a GVM upgrade, you’ll need to ensure your rims are up to the task.
Only steel wheels can be repaired, right?
Most people presume steel rims are the only rim types that can be repaired. Well, yes and no. Steel rim damage can be repaired on the side of the track with nothing more than a hammer – sometimes. There are times when you won’t be able to fix a steel rim; it depends on the damage done. If you split a steelie, kiss it goodbye the same as a split alloy rim. If it’s too far out of round and so severely damaged that it won’t hold air, forget it.
While most bends, cracks and splits in alloy rims can’t be repaired trackside, some can be repaired by experts – mostly nowhere near where you suffer the damage unfortunately. Liquid Metal Filler (and similar products) that make up a ‘steel-like’ hard compound which bonds to alloy and can be filed and drilled, can be used as temporary trackside fixes, but they will take time generally needing the tyre to be removed to affect the repair. This type of fix should only be undertaken to get yourself out of trouble as a last resort, as it probably won’t be structurally sound. The pros will reshape, weld, x-ray and check an alloy rim is fit for purpose if it’s repairable.
So, yes, you can repair an alloy, but a trackside repair job will literally be to limp you out of trouble. An expert’s hand will be needed to determine if the damage is terminal.
You get what you pay for
Regardless of which rim material you’re planning on ‘using’, you really will get what you pay for. Cheap non-load rated steel rims will bend easily, compared to brand name load-rated versions which will weigh much more and take a beating before bending. Cheap alloy rims might be porous and allow slow air leaks, they might be brittle and crack or snap easily under impact and really have no place at all on our roads.
Brand name alloys, depending on their manufacturing method, may be lighter or heavier than some steelies, and they will definitely be stronger and far less prone to damage than their cheap counterparts.
Talking about alloys
Yep, alloy rims are lighter than steelies but not by as much as you might think. Depending on the quality and manufacturing method an alloy rim can be similar in weight to its steel counterpart but could also weigh far less.
Strength wise, there is no one simple answer as to whether they are weaker or stronger than a steel rim.
So, here’s the long-winded answer. Small, medium and semi-hard hits can easily be taken by a good quality alloy rim without damage via cracks, splits or bends. Just ask some of the guys racing at the Dakar, most of those vehicles run alloy rims and they don’t hold back in climbing rocks, thrashing through sand and mud or rumbling over long-distance corrugated dirt tracks. They’ve suffered popped beads, blowouts and tear-jerking scraps on rocks, but those rims just keep rolling on, season after season.
If though, you hit a rock or other solid object at high speed, really, really hard, you will more than likely destroy an alloy rim beyond repair. And, in that event it’ll need to be tossed in the bin and replaced.
Speaking of repairs; alloys can, in fact, be repaired – provided they are not too severely damaged. The bad news is, it can’t be done trackside with a lump hammer and needs to be done by an expert. Having said that, if I cracked an alloy rim and needed to perform a bush repair to prevent air leaking around a bead or lip, I wouldn’t hesitate in mixing up some metal putty as a very temporary fix. Yes, I carry that sort of stuff in my toolbox.
Alloy wheel advantages
Let’s look at some advantages. Because alloys are a (mostly) lighter rim they create less unsprung weight for your suspension to control, allow effortless acceleration given there is less weight for your engine to spin which results in improved fuel consumption. Alloy rims should allow heat generated from your brakes to dissipate more readily than steel rims. But, again, whether most people would notice the real-life improvement would be debatable.
Given the manufacturing methods of an alloy rim things like roundness, trueness and weight balance should theoretically be superior to (almost) all steel rims. Ease of balancing the wheel (tyre and rim) should utilise fewer balancing weights compared to the same tyre on a steel rim, too.
What about the negatives…Personally, I’d find it hard not to cry if I damaged a nice alloy rim while changing a tyre trackside. Sure, I don’t like damaging a steel rim but seeing a chunk missing in an expensive alloy is heartbreaking.
Talking about steelies
Steelies are generally heavier than an equivalent sized alloy rim but the difference varies from a lot to negligible depending on quality. El Cheapo imported steel rims will be a lot lighter than a decent quality rim. Some of the heaviest steel rims I’ve ever had the pleasure of busting my guts lifting are original equipment 100 Series LandCruiser rims; they are heavy and extremely strong.
Yes, you can hammer a bent steel rim back into shape on the side of the track, provided it’s not been dented too much. Don’t think you’ll be just tapping lightly with your average claw hammer; you’ll need hefty swings with a lump hammer to straighten a strong, quality steelie.
A steel rim will bend easier than a quality alloy rim via a medium to semi-hard strike. But, it’s the harder, destructive hit that will see the alloy written off while the steelie might be repairable.
Which wheel is best off-road
While your robust, heavy steel rim will last the distance off-road, it’s not doing your day to day driving any advantages. That higher unsprung weight is working against everything from suspension workings, acceleration and braking performance. One slight advantage and I stress ‘slight’ might be that a heavy set of steel rims would return a better centre of gravity to your 4X4 with increased weight down low but, highly unlikely most drivers would notice any difference while driving on steep side slopes.
Costs alone would see many people, including me at times, happy to settle for steel rims. See, a quality steel rim can cost a quarter of an equivalent alloy.
As far as looks go, that’s just my personal opinion. Regarding restricted colour choices; most steel rims are white, black or silver; although, powder coating, spray painting and plasti-dipping can return plenty of colours and designs to enhance the looks. But it’s worth remembering that rust is the number one enemy of steel rims. Even powder-coated rims that live near the coastline will soon show signs of rusting. When they do, you’ll need to consider cleaning and treating the wheel, whether that’s with repainting or…
Wheel nuts are important
Wheel nuts must be suited to each rim to allow correct fitting. Noting the taper angle (often 60 degrees) of the wheel nut face must be the same angle as the mating face on the rim. Also, the depth or length of the wheel nut must be correct to suitably compress the rim to the hub. Getting the wrong angle and length nuts will only lead to potential tragedy as a wheel wobbles loose on the road. Note that alloy rim nuts are generally not suitable for steel rim wheel nuts because the designs are different given the different mating faces and hub centres.
Alloy rims look better…
Design-wise, alloy rims have many more options to consider compared with steel rims. Patterns, colours, styles and shapes… well, they’re all round, will attract different people. Beauty is in the eye of the beer holder, right. Steel rims do offer a few designs, but much less so. Some love the look of the age-old Sunraysia style and most only have options of white, black or silver. But painting, Plasti Dipping and aftermarket powder coating are all easily done.
Fitting the wrong rubber
On-road low-profile rubber is excellent for high performance, street-orientated handling, but is totally the wrong rubber for off-road use. That low profile rubber is also conducive to rim damage – regardless of steel or alloy. Given there is far less ‘give’ in the tyre sidewall, it stands to reason your rim will bear the brunt of a lot more impact. Higher profile, off-road-orientated tyres, will absorb far more shock from hitting rocks, or other hard objects, effectively protecting your rims. Sure, you should drive to the track conditions and slow down as needed, but the higher profile your tyres are, the less damage you’ll do to your rims.
So, alloy or steel?
I’ve used both aftermarket alloy and steel rims on the various 4X4s I’ve owned over the last 30-plus years. And, in all my years, I’ve never had a problem with either type being bent, cracked or damaged which I’d guarantee is part to do with my choice of suitable off-road rubber, as well as not driving like an out-of-control clown. All of the rims I’ve seen damaged have generally had low profile rubber fitted or the vehicle has been driven by a clown – way too fast and reckless.
Crunch time. After everything I’ve said, there’s no right or wrong answer when it comes to choosing a rim type and this isn’t a cop out. There are pros and cons of each, plus personal opinion regarding looks. Me personally, I like steel rims because they’re cheaper, and easier to fix by the side of the track if needed. That said, I’m currently running steelies on my Troopy but I’m on the lookout for a set of alloys.
Indeed, such are the advances in metallurgy that alloys are just about impossible to beat for 99 per cent of drivers with the exception of price when compared with steelies. Oh, and anyone who reckons alloys aren’t as strong as steel rims is stuck in the 1970s.
So, should you be swapping out your factory alloys on your tourer? Probably not. I reckon, once paired with the right rubber, they offer the best mix of all-round performance for tourers, weekend warriors and even most long-distance remote area explorers.