Is Steel Or Aluminum More Practical For A Truck Bed?

Steel or aluminum? That's the question many consumers ask themselves when shopping for a new truck. Whether you're a commercial fleet owner or the average driver, choosing between a truck with a steel bed or a truck with an aluminum bed can be a tough choice. Each has its own advantages and disadvantages, but anyone with an ear to the ground has heard Ford boasting about cutting down the weight of their 2015 F-150 by 700 pounds when they starting making body panels out of aluminum. We're going to come back to this later.

As more automakers go electric, aluminum is also becoming a much more sought after material for vehicle production. Steel definitely has some advantages, but the more we look at it, the more it seems like aluminum is the way to go. After some investigation, we've found that the lifespan of the truck bed and your truck overall can be impacted by your choice of an aluminum or steel body. Here's what you should consider.

This is a big one. Rust can destroy any vehicle or construct made out of steel. Unless you take your car in for maintenance often, untreated rust can spread once exposed to the elements. In the case of carbon steel, it can be treated to resist rust when combined with chromium. Carbon steel mixed with chromium creates stainless steel, which is generally more expensive and can still be vulnerable to corrosion.

In contrast, aluminum truck bodies are highly resistant to rust and other forms of corrosion. Thanks to its protective oxide layer, it's less likely to have its structural integrity compromised by outside elements. Of course, different aluminum grades can have more or less resistance to corrosion. For instance, if the aluminum has been mixed with copper and magnesium, it loses its corrosion resistance but increases in strength. More on that next, but as it stands, this round goes to aluminum.

How durable is aluminum? Being the more rigid of the two, steel is the better option in most cases. Designed for tough jobs that require a truck bed to take a beating, high-carbon steel can handle 965 megapascals (MPa) of pressure, whereas its aluminum counterpart can only handle 710 MPa. Auto manufacturers know this, and they have been able to increase its strength even more in recent years by adding ridges to the truck beds. Steel sure sounds like the winner here.

However, aluminum can always be strengthened. Since it's a flexible alloy, aluminum can also be combined with additional elements, such as magnesium, zinc, silicon, molybdenum, and copper. However, some of these elements can also affect how resistant the material is to corrosion. Beyond that, the strongest aluminum is saved for machine parts and aircraft. That said, plastic composites may replace aluminum on planes in the near future, so that could change.

If we're not too worried about the strength and want to look at the weight, then aluminum immediately starts to look like the better option. Aluminum weighs about one-third as much as steel and offers a good strength to weight ratio, which means you often get a lot more bang for your buck.

Speaking of weight affecting performance, let's look back at the aluminum 2015 Ford F-150. Depending on what the truck bed and body are made out of, you can be looking at a difference in payload and towing capacity. It may seem like a negligible difference, but the reality is that the maximum payload for a 2014 F-150 made with steel was around 3,100 pounds while a 2015 F-150 made with aluminum could haul 3,300 pounds.

In terms of fuel efficiency, aluminum truck bodies have been proven to generate more mpg due to the reduced weight. The fuel efficiency of the rear-wheel drive 2015 Ford F-150 improved by 29% over previous model years when it switched over to aluminum, offering 19 mpg in the city and 26 mpg on the highway. Weight decreases even more with aluminum because the lighter the body, the smaller the engine that is needed to power it. Moreover, a lighter truck body will put less stress on other vehicle components, such as the truck's suspension system.

So if aluminum is so great, surely it costs more, right? For the most part, that is the case. Upfront, aluminum truck beds tend to be more expensive. Carbon steel is generally less expensive at about half the cost of aluminum. If something costs an auto manufacturer more money, then the company will shift that over to the retail price to make a profit. Of course, the market isn't always dependable, and one element may be favored over the other today, tomorrow, or next year. 

However, you should take into account the savings an aluminum truck bed will bring you. We already know you'll have better fuel efficiency, and because it's less prone to rust, you'll have lower maintenance costs to contend with. Steel requires rust prevention treatments, such as coating the underbody to protect vital components, which can cost as much as $1,000. If you don't take preemptive measures and skip out on your car maintenance, the cost of repairs for rust damage and repainting will only grow.

So which will be better for your next truck? Steel has proven to be a dependable choice for decades, but the reality is that advances in aluminum manufacturing have made it an increasingly viable option. If the potential benefits to fuel economy, rust resistance, and payload capacity offset any added costs, then an aluminum truck bed could be the way to go.