A Question on Pick-up Trucks

I have watched and read that all steel trucks and SUVs are being phased out. For pickup trucks, does the aluminum construction provides reliability? I don’t care much about MPG since in my opinion; a person should not even think much of the MPG if buying a truck.

My main concern is reliability and life of the truck. There was one thread here dated 04/2015; I have read that already but it mostly deals with the repair shops for aluminum body trucks.

So does steel provides longer life and reliability than aluminum? Not sure if Toyota still uses steel for the trucks. But I am sure Ford now uses aluminum for the F150.

I don’t plan to buy or replace my existing sedan yet. This is just for research purposes; for future use.

It’s only one Ford model that has switched to aluminum construction. that is not “all trucks and SUVs”. Where did you get that info?

Aluminum would be more expensive but you will never have rust issues. Presumably the thickness is adjusted so the strength is the same as steel.

The idea for Ford using aluminum for the truck body is to have the same body strength at a lower truck weight; therefore better fuel economy. There may be some benefits in the braking and cooling systems too due to the reduced body weight.

I’m not a metals expert, but I do have some limited experience in another type of vehicle. Mt. Bikes used to be made of steel, but most of them are now aluminum or carbon fiber for the same reason, weight reduction. I’m not aware of any reduction in durability due to the switch to aluminum, although there does seem to be some compromises in durability w/carbon fiber.

For aluminum – as far as Mt. Bikes go – the main complaint is that it is more rigid, less flexible than steel. That might contribute in trucks to a worse ride, so my pin-head thinking is this advice: pay att’n to ride quality in the test-drive phase if considering aluminum trucks.

For regions where salt rusts bodies aluminum could be a great benefit but not here in the south and certainly not in the southwest. And if avoiding body rust is worthwhile why not opt for more plastic in rust prone areas?

I understand that Ford is using an aircraft grade aluminum. When I was in the Navy, I worked on F-14’s, some were about 10 years old and had been slammed into the flight decks of aircraft carriers at 130 mph thousands of times, pulled 8+ G’s and in general misused and abused by the young hot shot pilots over the years, and they held up pretty good.

The frame is steel, the body panels aluminum. No problem there.

And if avoiding body rust is worthwhile why not opt for more plastic in rust prone areas?

The WHOLE car is rust prone. If there’s metal…it’s prone to rust.

You either user a different material (plastic doesn’t make a good frame material), or you coat it with a rust proofing material…or MOVE South.

You’ll soon be seeing Chevy truck commercials touting the advantages of steel over aluminum. It’ll be a LONG time before steel gets replaced by other makers.

Ford’s aluminum body is about pursuing high efficiency ratings by the feds and giving the impression of high efficiency in the marketplace.
Chevy is already advertising that their bodies are steel. Ford’s idea just might backfire on them.

It’s impossible to really compare the two. Aluminum doesn’t rust, but it will oxidize, and the alloy and treatments of the aluminum in the manufacturing process make a huge difference. Aluminum has lower tensile strength than steel, and can fracture when bent. It also doesn’t absorb vibration as well as steel. But once it starts oxidizing, it form an extremely hard aluminum oxide layer that doesn’t flake off like oxidized steel (rust) does.

However, I should point out that aircraft are structurally 100% aluminum, and there are aircraft out there that have been flying since the 1950s. There are DC3s out there still in service (civilian) whose hours of flight time are no longer being tracked. The newest B52 in the Air Force’s inventory was accepted by the AF in 1962.

Bottom line: ignore the steel vs. aluminum debate. If you’re I the market for a truck, and you like one in particular, and its reliability record is good (see CR), go for it. Leave the material choices to the engineers.

I guessed that most people who buy new cars would trade when rust became evident on the body @Mike. But I have seen some cars and trucks that were one good bounce away from needing a dust pan to carry them away so I do recognize your point re frame rust.

I always thought aluminum rusted or oxidized just like steel, if it isn’t protected by some surface treatment. Is it true that unpainted aluminum is rust-proof?

@BillRussell

“you will never have rust issues.”

Unfortunately, you’re not entirely correct

The aluminum bodied Ford truck uses a steel frame

So rust is a very real possibility. Maybe not likely, but certainly possible

As far as I know, there are no plans to build truck ladder frames out of aluminum

Maybe I’m wrong, but I haven’t heard of it yet

Aluminum not so good for frames,the KWs and other trucks would develop serious cracks in the frames after a pretty good interval,there are some grades or alloys of aluminum with tensile strength with or exceeding the tensile strength of mild steel.Aluminum will turn into red powder in the presence of Mercury,when you scratch Aluminum,a tough oxide layer forms on the surface almost immediately(Aluminum is highly reactive,alkalies affect Aluminum big time also)As far as Chevy bragging about their use of of steel,their thin guage sheet metal has never impressed Me ,visions of rusted out cab corners and rocker panels dance through my head,when I look at older Chevys.

I didn’t know that the bodies were steel, but makes sense. Aluminum is prone to cracking under repeated stress. Remember the De Havilland Comet.

Aluminum will not rust (rust is a compound of iron and oxygen). Aluminum will oxidize, but the aluminum oxide forms a protective coating preventing further oxidation.

“Aluminum will oxidize, but the aluminum oxide forms a protective coating preventing further oxidation.”

That’s true but once aluminum oxidizes…it becomes weaker. My aluminum boat became so weak that I stepped right through it at the lake. Same thing with my porch swing when I tried to sit on it last year. All the joints started breaking. In all fairness…both the boat and the swing were several years old. I sold them as scrap and recouped some of my money.

Aluminum quickly develops a very thin oxide film and stops at that point.

edit - aluminum does have problems with repeated stress causing failure (remember the Hawaiian Airlines 737 that lost part of its structure in flight?), and saltwater can cause corrosion, along with problems with galvanic corrosion when other metals are in contact.

Rust is an oxide that falls away, aluminum oxide stays attached to the parent material so the aluminum truck body won’t disintegrate like steel bodies will. Aluminum doesn’t have the fatigue resistance of steel but a truck’s body doesn’t really take the lion’s share of the load, the steel frame does. The frame will still rust but since it is much thicker, it takes much longer to rust away (unless it is a Toyota, of course!) so that isn’t as much an issue. Truck bodies and beds still need strength so plastic is not really an option.

Lots of development went into carbon-fiber and fiberglass reinforced plastic truck beds to a) reduce rust-out and b) reduce weight in the early 2000’s. It didn’t fly because it took too long to cure the single-piece bed-fenders-floor to make it cost effective. It was at a project at a composites research facility run by my old boss.

Unit body cars have been made from aluminum sheet for quite a while so the technology is there to form it, paint it and repair it. Any increase in MPG’s for the best selling truck in the US saves a boatload (literally, a tanker-full) of oil. GM is just protecting their turf. Time will tell if Ford did the right thing.

Recently Car and Driver did a comparison test, and the Ford and Chevy pickups tied in performance, the Ford was all of 80 pounds lighter, and they both managed 16 mpg overall. So the aluminum + Ecoboost on the Ford had about zero impact.

I suspect that the phenomenon that Missileman experienced was the aluminum oxide being gradually removed from the boat’s surface by the erosive effects of the water. While aluminum oxide does not by itself fall from the surface the way iron oxide does on iron, it can be removed mechanically.

Can’t guess about the swing. Perhaps gas passing wore it out? {:smiley:

Now that’s amazing @texases. My old F-150 (1991) with a 4.9L automatic consistantly gets 17+ miles per gallon which beats current truck mileage according to C&D.