Steel vs. Aluminum – weight comparison???

[Richy_Rich]

For the Engineering crowd(not me) please help me ponder this hypothetical… what would a Camaro weigh if it were all aluminum?

Since I cannot find how much steel / other metal is used in the production line of building a Camaro… and cannot break out the amount of weight that comes from all other materials - then I only have the base weight to use. I believe the Chevy site states 3860lbs for a 2SS; so given fluids and misc… I use 4000lbs as a base number.

The idea… if 1 cubic foot of steel is ~489lbs and 1 cubic foot of aluminum is 169lbs, then there are ~8 cubic feet of steel in a Camaro to equal 4000lbs (4000 / ~489lbs = ~8).
- The concept, if it takes 8 cubic feet of a “steel” to make a Camaro, then it’s equivalent in aluminum would equal 1352lbs!

I know the numbers seem crazy, and I doubt GM would ever build an all aluminum Camaro, b/c of the cost and fact that the Z06 / ZR1 vette have this already. But imagine the potential; as steel verses aluminum has a 320lb weight advantage over steel.

What started this line of thinking – a report that GM has patented a new manufacturing process for welding aluminum and a mention of it saving weight in the next decade of production runs on their cars. The idea is that engine power can stay relatively the same, but gain mileage and performance due to weight reductions.

GM is at it again!

[Juiced1]

The frames on the Z06/ZR1 are aluminum while the standard C6 is steel. The Z06/ZR1 frame is said to be about 136lbs lighter. It's a good idea but it does add serious cost which would come right out of the buyers pocket. Fiberglass and carbon fiber body panels can help lose weight as well but again, they will add cost. With saftey standards increasing every year it becomes difficult to decrease weight working on the same platform (It's currently on the Zeta platform which houses mostly full size sedans). It's said the next generation Camaro will be on the same platform as the lightweight ATS Caddillac. This should be a good start in the right direction.

As for you numbers....don't forget that the entire LS3/L99 engine is already aluminum and you have a good deal of weight from the interior and other plastics such as bumpers and what not. Just guessing by the weight savings on the frame, I would think you could lose another 100-125 in the body and maybe another 100-125 in the suspension. I could be way off but who knows.

[toehead93]

Look at the new Cadillac ATS, it has a combo of lightweight steel, magnesium, and aluminum...this is the gen 6 platform and it is 3,400lbs with a V6 and 4 doors!

[Richy_Rich]

Originally Posted by toehead93

Look at the new Cadillac ATS, it has a combo of lightweight steel, magnesium, and aluminum...this is the gen 6 platform and it is 3,400lbs with a V6 and 4 doors!

Nice!

[DGthe3]

Originally Posted by Richy_Rich

For the Engineering crowd(not me) please help me ponder this hypothetical… what would a Camaro weigh if it were all aluminum?

Since I cannot find how much steel / other metal is used in the production line of building a Camaro… and cannot break out the amount of weight that comes from all other materials - then I only have the base weight to use. I believe the Chevy site states 3860lbs for a 2SS; so given fluids and misc… I use 4000lbs as a base number.

The idea… if 1 cubic foot of steel is ~489lbs and 1 cubic foot of aluminum is 169lbs, then there are ~8 cubic feet of steel in a Camaro to equal 4000lbs (4000 / ~489lbs = ~8).
- The concept, if it takes 8 cubic feet of a “steel” to make a Camaro, then it’s equivalent in aluminum would equal 1352lbs!

I know the numbers seem crazy, and I doubt GM would ever build an all aluminum Camaro, b/c of the cost and fact that the Z06 / ZR1 vette have this already. But imagine the potential; as steel verses aluminum has a 320lb weight advantage over steel.

What started this line of thinking – a report that GM has patented a new manufacturing process for welding aluminum and a mention of it saving weight in the next decade of production runs on their cars. The idea is that engine power can stay relatively the same, but gain mileage and performance due to weight reductions.

GM is at it again!

One problem with that idea is that when you replace steel with aluminum, you need to use more material to maintain the overall strength. The rule of thumb is that for a given strength requirement, an aluminum part will weigh roughly half of what a comparable steel part will weigh.

This gets further complicated by the use of high strength and ultra high strength steel. Replacing those alloys with aluminum yields minimal weigh savings. And again, complicating things even further ... certain parts on the Camaro cannot be made of aluminum using current manufacturing processes. Such as the outer rear 1/4 panel. It is such a big and complicated piece that it isn't possible to stamp it out of a single piece of aluminum. It could be made from 2 stampings which are then welded together, but that adds even more cost and causes even more manufacturing headaches (although ... given how much of the car would need to be re-engineered in a switch to aluminum, this may end up as a mere drop in the bucket).




With your estimate, even if we don't have numbers for how much steel vs aluminum vs other materials there are in the Camaro, there is most definately not 4000 lbs worth of steel in there. Making assumptions is fine when doing rough calcs for a thought experiment like this ... but make sure they are reasonable assumptions. For example, the Camaro doesn't have steel tires, or steel seat cushions, or steel gasoline. So, we have to approximate the weight of these things (and anything else that we can think of that either isn't steel or can't be made of aluminum).

The engine (mostly aluminum) is some 450 lbs. Transmission & axles, probably 300 or more. Wheels & tires combine to around 300 lbs. Brakes & suspension pieces, another couple hundred (remember, it only takes 50 lbs per corner to equal 200 lbs). The interior is another few hundred. Fluids (coolant, oil, gasoline, etc) are going to be another 200 or so. Add that up & we're up to around 1/2 the weight of the Camaro already.

So even if the rest of the weight were steel (it isn't), we're looking at an absolute bare minimum of 3000 lbs for an aluminum Camaro. That assumes there is 2000 lbs worth of steel that can be replaced by 1000 lbs of aluminum. More likely, I'd say it would be a total weight of around 3500 lbs, maybe a bit less. And while we're speculating, I'd say that this ~3500 lb all-aluminum Camaro would probably be price competitive with something like an Aston Martin V8 Vantage. I have nothing at all to base that guess on though.