All automotive hoods must meet specific safety standards and regulations before they can be used on vehicles. That means there is more common ground when comparing steel and aluminum hoods than most people realize.
Hoods must also absorb the energy of an impact while having controllable deformation behavior during a collision.
When comparing an OEM steel hood of the same design with an aluminum one, the primary difference is found in stiffness deflection.
Steel can withstand a significant amount of force when compared to aluminum without having problematic torsion.
Hood – Steel vs. Aluminum
The two most common metals used for automotive hoods are steel and aluminum. When the two products have a nearly identical design, steel offers better stiffness values. Aluminum delivers a significantly lower weight. Since it can withstand more force, steel hoods also prevent more injuries.
| STEEL HOODS AVERAGE | ALUMINUM HOODS AVERAGE | COMPARISON PERCENTAGE | |
| Hood Mass: | 37.36 pounds | 19.84 pounds | 46.9% |
| Outer Panel Thickness: | 0.0267 inches | 0.0393 inches | 47.1% |
| Inner Panel Thickness: | 0.0228 inches | 0.0393 inches | 72.4% |
| Lateral Stiffness: | 97.17 N/mm | 66.42 N/mm | 31.6% |
| Torsional Stiffness: | 97.70 N/mm | 63.81 N/mm | 34.7% |
| Transversal Stiffness: | 2.58 N/mm | 1.82 N/mm | 29.5% |
Aluminum hoods are also helpful for providing a safe driving experience. The goal of each automaker should be to examine the constructive optimization of each material to reduce the severity of injury during a collision.
Both hoods also struggle to create pedestrian safety benefits. Today’s vehicles are meant to protect the people inside the cabin – not an unprotected individual who comes into contact with the car.
Steel vs. Aluminum Hoods for a Vehicle
When you want to have less weight while driving, your hood is one of the first options to consider. That chunk of metal can get heavy when made with steel, so some automakers are transitioning to aluminum.
The 2015 Ford F-150 went even further, becoming one of the first heavy-duty trucks to use an all-aluminum body. This design change allowed the automaker to take an incredible 700 pounds away from the truck’s weight.
Fleet vehicles have a goal to reach 54.5 miles per gallon by 2025. The Ford F-150 has been the best-selling vehicle in the United States for four decades.
Having aluminum replace steel is a way to make things lighter while delivering similar safety features.
On the other hand, steel is nearly 40% less expensive to produce. At a time when semiconductor chips and other product shortages make it more costly for consumers to buy vehicles, it might make more sense to use steel as a way to lighten the financial load.
How Strong Is Aluminum?
Although vehicle test ratings show that steel is often stronger than aluminum, the metal shouldn’t be considered a weakness in any automotive design. When it’s manufactured correctly, it can be one of the most rigid materials on the planet.
Cars, trucks, military vehicles, and buildings all use high-strength aluminum in various ways. There is even an aircraft-grade metal that delivers exceptional support in diversified applications.
That’s why it is essential to review these takeaway facts when comparing steel vs. aluminum hoods for your vehicle.
1. Aluminum is used in everything.
You can find high-strength aluminum alloys in hundreds of products that we use daily. It’s implemented in anything that requires guaranteed durability and strength. Even some of today’s most prominent skyscrapers use this metal to create their impressive heights.
2. It thrives in harsh conditions.
You can find aluminum products withstanding some of the most challenging natural environments that we have ever encountered.
NASA uses it for their construction needs, while the U.S. military implements numerous vehicle designs and structures with this product. It can take on whatever you can imagine when crafted as a hood for a car, truck, van, or SUV.
The U.S. Air Force used to fly planes made with wood, wire, and fiber. When they started using steel, it was considered an impressive innovation! One of the world’s most famous fighter jets, the F-16, is 80% aluminum.
3. The properties get modified with different alloys.
When adding elements like lithium, magnesium, or silicon to pure aluminum, special processing techniques allow the final product to be stronger than some steel.
Since the metal is about one-third the weight of steel, you can make parts thicker and stronger while keeping the weight down for an improved fuel economy.
By highlighting the strength of the metal, it can be formed into different shapes for various purposes. Aluminum is the natural choice for shark cages because it has more buoyancy and corrosion resistance when compared to steel.
If it can take on an attack from a Great White, it can certainly handle a fender bender on the Interstate.
4. Processing techniques give aluminum even more strength.
If giving aluminum some beneficial alloys wasn’t enough to make it strong, the industry’s different processing techniques can provide it even more. Today’s manufacturers use hot or cold rolling methods to create results based on the materials and metals involved.
Another option is to heat-treat the aluminum before rapidly cooling it. That process freezes the atoms while strengthening the overall result.
Some aluminum is cold-worked the entire way to make it stronger.
If you have a 7,000-series aluminum alloy, it reaches strengths of 72,000 pounds per square inch. That’s strong enough to lift an entire 18-wheeler with a full load on a 1.2-inch wire.
Is Steel Stronger Than Aluminum?
Although steel faces more corrosion risks than aluminum, it is still a more rigid metal when compared through general manufacturing processes.
Cold environments do increase the strength of aluminum, but it is still more prone to scratches and dents than steel.
Steel is also less likely to bend or warp when it encounters heat, force, or weight. Those resistance properties are the reason why the material is still used by automakers all over the world.
Steel’s strength comes from a weight and density that is 2.5 times more than aluminum. Although that means it weighs more, it’s still 60% lighter than concrete. That’s why it has almost the same versatility levels when looking at various construction opportunities.
The one primary advantage that applies in all situations is that steel absorbs heat better than aluminum. That means you can support your engine compartment with a hood made from this metal.
Although aluminum helps it to dissipate into the environment, some vehicles might run a little hotter because they don’t have a steel hood.
Where Can I Buy a New Hood for My Car?
The easiest place to get a new hood for your vehicle is to work with your local dealership. They can access OEM parts on your behalf, schedule a time to get your car in for the repair, and complete the work for a competitive price.
If you don’t have access to a local dealership, the next place to shop is online. When you look on Amazon for replacement hoods, you’ll find more than 2,000 results available. From there, you can filter the products related to your vehicle by adding your make and model to your garage within your profile.
When shopping for a new car hood, please remember to read the listing carefully. You’ll find everything from covers to interior latch releases.
The steel or aluminum hood you select should be a direct replacement for the one on your vehicle. If it doesn’t say that it’ll work for your make and model, you should assume that it doesn’t fit.
Although you could take care of the hood replacement at home, it’s usually easier to have this job completed by an experienced vehicle body care professional.
A Final Thought About Steel and Aluminum Hoods
One of my favorite vehicles of all time is the 1957 Chevy Bel Air convertible. It has the long lines of a full-size car with the fins in the back that don’t protrude very high.
If you’ve seen the sea green version with white accents and chrome trim, it’s hard not to fall in love, especially with the late second generation design.
Those old Chevys were beasts on the road because they were made from steel. You were behind the wheel of almost two tons of metal. That’s why you needed a V8 engine and a strong gear ratio to even get it going.
I might love that design, but it doesn’t make sense when today’s aluminum processes create a similar product that is much lighter.
I’ll be the first to tell you that they don’t make cars like they used to these days. In some ways, that’s a good thing. With less weight, we’re burning fewer fossil fuels.
Today’s aluminum manufacturers can also create more metal while reducing the emissions profile of the entire industry.
Those reasons are why aluminum is the second-most common metal found in the modern automobile. Although it might not be as protective with a similar design to a steel hood, maybe we should think about updating the look to reflect its strengths.