GM is going aluminum

[Groover]

According to an article in the Wall Street Journal Chevy and will GMC will going aluminum 4 years after Ford.

http://finance.yahoo.com/news/gm-readying-aluminum-body-trucks-032223285.html

It will be interesting to see how this affects the debate on the merits of aluminum.

[Wes_Tausend]

maxwell11 wrote:
gm will be making their trucks with AL bodies following ford to get the weight down for fuel mpg goals I guess.
Will cut the weight, but wonder how it will hold up in the real world, salt, road grime, etc: over the years.

Wonder if the engineering dept has any old school logs left from back in the day:
Do you remember GM trucks back in 1973-1975, they changed something in body protection and some bed fender wells and cab corners were rusting out in 6 months.

I stated that frames usually are not made of aluminum, but I owned a 2000 Chevy Impala that used a thick aluminum K-member. We really liked the car, great mileage.

The K-member merited an unofficial recall; it went back for a simple mod to prevent a clunk when turning. I assume something worked loose or cracked, but we didn't clunk yet. The "new" chassis replaced the aging Lumina sedan that year and was a derivation of an earlier Buick chassis. The Buick had some front suspension rust problems and perhaps went aluminum partly for that reason in conjunction with the continuous GM program of weight savings.

I think the most exotic thing on the 2000 Impala was an intricate cast magnesium dash bulkhead behind the firewall. The thick, bulky piece added a great deal of stiffness to the now squeak-free cowl, which is partly why the unibody could handle high powered pursuit V-6's and even the torque and bulk of a V-8 in future years. Of course the magnesium added a lot of adequate stiffness for no weight increase over adding copius room-robbing steel sheetmetal webbing.

Styled like a Mercedes sedan, one could buy two Impalas for the price of one Mercedes, thereby outlasting them for the money. As always, prestige was another story... "Oh Lord".

Wes
...

[maxwell11]

gm will be making their trucks with AL bodies following ford to get the weight down for fuel mpg goals I guess.
Will cut the weight, but wonder how it will hold up in the real world, salt, road grime, etc: over the years.

Wonder if the engineering dept has any old school logs left from back in the day:
Do you remember GM trucks back in 1973-1975, they changed something in body protection and some bed fender wells and cab corners were rusting out in 6 months.

[Wes_Tausend]

FishOnOne wrote:
I'm not sure I agree with all this... Ever compare the weight and strength of titanium to Stainless steel.

In addition removing weight from a vehicle will improve highway fuel economy. Try a highway fuel economy test with your current truck with and without 1k pounds in the bed of the truck.

Titanium benefits on some things but doesn't pay off on others. See post above. As an example, Titanium works for MX bike axles (unsprung mass), valves and rods. Aluminum would improve some of these high reciprocation cases except it fatigues where steel and titanium don't. Magnesium, at 25% less mass than aluminum, helps for engine covers and once in a while wheel hubs (unsprung mass again). These more expensive materials are all used only where the payoff is greatest.

Highway mileage will improve with lighter weight but not as much as city driving where a large percentage of fuel is used to heat brakes in stop-&-go. That's why a Prius Hybrid (with brake energy recovery) might get 60 mpg in town as opposed to my old '94 Escort that got only 31 mpg. A 10% decrease in rolling resistance nets about 2% better highway economy at best, so a 15 mpg truck becomes 15.3 mpg. In town 1k less might be good for 3 mpg instead of .3 .

Wes
...

[Wes_Tausend]

Passin Thru wrote:
YOu can't buff the tailgate, CA will give you a ticket for blinding someone following you. Stupid law but that's why they have quilted aluminum doors on Great Dane Trailers.
Wes Tausend, Why do they use Titanium on airplanes if it isn't stronger and lighter than steel? I sure broke a lot of drill bits adn screwdriver bits on titanium. Also, I read an arcticle thant said Carbon Fiber was corrosive to any metal it touched due to dissimilar metal corrosion. The use of carbon-fiber composites with steel structures requires a thorough understanding of the phenomenon of galvanic corrosion. In theory, as long as two materials have not
contacted each other, a corrosion cell will not initiate. However,
in case of direct contact between carbon fibers and steel
in the presence of an electrolyte, the wet corrosion cell could
accelerate the corrosion of steel and create possible blistering
and subsequent delamination or debonding.
Probably why they don't use carbon fiber in vehicles that run down roads we salt and use calcium chloride on.

Titanium isn't quite as strong as some high strength steels, but it is stronger than aluminum. But you right, it is considered lighter for the strength it has. But not as much as one might think for practical purposes, depending on how it is used. That is what I meant by "sort of" in my post above. Also, I admit I was mostly thinking of steel vs aluminum as I mis-spoke. Titanium is mostly used on fighter jets because it is resistant to heat from air friction. It is used on just a few other items where composite, steel or aluminum won't do.

Below is a partial (crooked) chart of Specific Strength (strength per density).
Stainless steel is at 254 whereas Titanium is at 288. They are fairly close together, as opposed to stronger Balsa which is at 521, or weaker aluminum which is only at 214. Aluminum is stiffer than steel per weight which is why it makes good panels and this probably related to the lower Fatigue Limit, making less durable frames.

...................................Material.....................Density...........Specific Strength
.....................................Strength.................(g/cm³)...............(kN·m/kg)
......................................(MPa)
Magnesium........................275_________1.74____________158
Aluminium.........................600__________2.80____________214
Stainless steel.................2000_________7.86____________254
Titanium...........................1300_________4.51____________288
Bainite.............................2500_________7.87____________321
Balsa (axial load)...............73__________0.14____________521
Scifer steel wire.............5500__________7.87____________706
carbon-epoxy compo.....1240_________1.58____________785
spider silk......................1400__________1.31___________1069
Silicon carbide fiber.....3440__________3.16___________1088
Glass fiber....................3400___________2.60___________1307
1 ?m iron whiskers......14000__________7.87___________1800
Carbon fiber (AS4).......4300__________1.75____________2457
Kevlar.............................3620__________1.44____________2514
Carbon nanotube.........62000_________.037-1.34________46268
Colossal carbon tube.....6900___________.116__________59483

Note that the strange Scifer Steel wire has an unusually high tensile strength.
"The scifer wire is said to be composed of 97 percent steel, 2.9 percent silicon and manganese and 0.1 percent carbon. The material is available for 43 cents per kilogram."
It appears to only work this way as a thin thread however.

Carbon fiber is electrically conductive and, unisolated, it can react with metals (especially aluminum), not a lot different than the carbon anode in a zinc-carbon battery. OTOH, a carbon body makes a better ground plane for an antenna than fiberglass. Most Corvettes have a metal plate under the rear deck for this reason. But some do have other carbon body panels. Wonder if they're eroding?

Wes
...

[FishOnOne]

Wes Tausend wrote:
...

There are some misunderstandings when it comes to aluminum.

For equal strength, equal weight is required. One material is not stronger per pound than another. Sort of. Advantages do depend on how one, or the other, is used.

Aluminum works best for panels, hulls and aircraft skin because it is less dense and sheets are thicker. Just like some noted, the extra thickness is resistant to flex. Most of the coming vehicular advantages rely strictly on this principle. The thinner and thinner high carbon steel panels now used on body panels are about at their "thin" limit. It is unlikely that the entire body (ala Jaguar) or automotive frame will ever be aluminumm because of rapidly diminishing returns on investment. Too expensive, too exotic. Offhand, someone mentioned using aluminum on 3/4 tons. This was already done on my 2000 Excursion 14 years ago; the rear hatch doors are aluminum.

The reduced weight will not improve highway mileage much at all. Reducing extra weight on highway travel only decreases rolling resistance by a negligible amount. Once something is rolling, wind is the enemy. Sure, uphills are harder, but following downhills recover much of the used energy; unless one must brake. But light weight will improve stop & go city mileage, thereby raising combined economy to meet new standards. That is the plan.

The repair of aluminum is slightly different, but a rather simple process. My guess is that Ford will supply white sheet information materials to any receptive body shops, maybe even hold low cost "coffee/donut" Rep seminars at nearby dealers. $10k sounds way out of line, maybe the cost of an entire sales region.

Autobody craft organizations are already on top of this. There should be very little welding on aluminum. The only differences are using adhesives and/or rivits, plus the correct etching and primers. Most body shops already use adhesives on steel rather than weld, and are familiar with new coating/gluing products. Expect body shop suppliers to jump into the new market with their own enthu$iastic training. After all, brittle high-carbon steel panels are already R&R'd (remove & replace) rather than hammered out. The new thin steels are almost spring steel temper and don't work-form well anyway. This transition should be a piece of cake, easier than learning fiberglass, clear-coat systems and plastic interior trim/urethane bumper repairs.

Wes
...

I'm not sure I agree with all this... Ever compare the weight and strength of titanium to Stainless steel.

In addition removing weight from a vehicle will improve highway fuel economy. Try a highway fuel economy test with your current truck with and without 1k pounds in the bed of the truck.

[Passin_Thru]

YOu can't buff the tailgate, CA will give you a ticket for blinding someone following you. Stupid law but that's why they have quilted aluminum doors on Great Dane Trailers.
Wes Tausend, Why do they use Titanium on airplanes if it isn't stronger and lighter than steel? I sure broke a lot of drill bits adn screwdriver bits on titanium. Also, I read an arcticle thant said Carbon Fiber was corrosive to any metal it touched due to dissimilar metal corrosion. The use of carbon-fiber composites with steel structures requires a thorough understanding of the phenomenon of galvanic corrosion. In theory, as long as two materials have not
contacted each other, a corrosion cell will not initiate. However,
in case of direct contact between carbon fibers and steel
in the presence of an electrolyte, the wet corrosion cell could
accelerate the corrosion of steel and create possible blistering
and subsequent delamination or debonding.
Probably why they don't use carbon fiber in vehicles that run down roads we salt and use calcium chloride on.

[v10superduty]

Perrysburg Dodgeboy wrote:

Tne insurance industry is not going to eat the cost so the only way to keep rates the same as the current trucks ks if the repair cost are the same right?

Don

Don..
There is more to the cost of insurance on a vehicle than the repair cost. I had pointed this out before. Applies in Canada but I am confident applies in USA also with the tendancy to sue.

Ask your own insurance broker this question..

What would cause rates on a new vehicle to go up more?
1--The cost to repair a crash of $10,000 to $20,000?
OR
2--The higher or lower probability of me getting hurt in said crash?

So if the new aluminum body trucks from Ford (and later GM and Fiat) have higher crash/safety rating than the ones they replace, the insurance cost will in some case not go up at all.
$10 or even $30,000 is nothing to a big insurance company but $250,000 plus $100,000 yr for rest of someones life due to severe injury is what they worry about.

[Wes_Tausend]

...

Thanks, Turtle.

Wes
...

[Turtle_n_Peeps]

Great post Wes. 🙂

[Wes_Tausend]

...

There are some misunderstandings when it comes to aluminum.

For equal strength, equal weight is required. One material is not stronger per pound than another. Sort of. Advantages do depend on how one, or the other, is used.

Aluminum works best for panels, hulls and aircraft skin because it is less dense and sheets are thicker. Just like some noted, the extra thickness is resistant to flex. Most of the coming vehicular advantages rely strictly on this principle. The thinner and thinner high carbon steel panels now used on body panels are about at their "thin" limit. It is unlikely that the entire body (ala Jaguar) or automotive frame will ever be aluminumm because of rapidly diminishing returns on investment. Too expensive, too exotic. Offhand, someone mentioned using aluminum on 3/4 tons. This was already done on my 2000 Excursion 14 years ago; the rear hatch doors are aluminum.

The reduced weight will not improve highway mileage much at all. Reducing extra weight on highway travel only decreases rolling resistance by a negligible amount. Once something is rolling, wind is the enemy. Sure, uphills are harder, but following downhills recover much of the used energy; unless one must brake. But light weight will improve stop & go city mileage, thereby raising combined economy to meet new standards. That is the plan.

The repair of aluminum is slightly different, but a rather simple process. My guess is that Ford will supply white sheet information materials to any receptive body shops, maybe even hold low cost "coffee/donut" Rep seminars at nearby dealers. $10k sounds way out of line, maybe the cost of an entire sales region.

Autobody craft organizations are already on top of this. There should be very little welding on aluminum. The only differences are using adhesives and/or rivits, plus the correct etching and primers. Most body shops already use adhesives on steel rather than weld, and are familiar with new coating/gluing products. Expect body shop suppliers to jump into the new market with their own enthu$iastic training. After all, brittle high-carbon steel panels are already R&R'd (remove & replace) rather than hammered out. The new thin steels are almost spring steel temper and don't work-form well anyway. This transition should be a piece of cake, easier than learning fiberglass, clear-coat systems and plastic interior trim/urethane bumper repairs.

Wes
...

[Perrysburg_Dodg]

Ford has said they are to eat the up costs of going aluminum when they said they are "not raising tne price of the new F-155". Now they are saying that the replacment panels and fornt structure costs are not going up? Sorry but these components costs are a lot highter then comparable parts made out of steel. So the only way to price them tne same is for Ford to eat the increase. If they do how long are they willing to do this? Aslo will GM be willing to do the same?

Tne insurance industry is not going to eat the cost so the only way to keep rates the same as the current trucks ks if the repair cost are the same right?

Again buy anything you want just make sure you know what the costs will be before you buy. I sure as hell would not believe any thing a manufacturer is saying when it comes to this. If you really think Ford is telling the truth I have a bridge I will sell you. Yep they where sssooooo honest wih me....not. Again I don't care what you buy.

Don

[hone_eagle]

Not PARTS - training and tooling,"Ford has all but said"??
doubt it
they will pass part costs on to insurance companies,
new always costs a fortune to fix/insure.
They will be under a microscope for sure .
selected means 'how many did you sell? did you screw/overcharge any customers? Did you comply with warranty quotas?
etc

[Perrysburg_Dodg]

Bob not trying to sway anyone toward a Ram by my post. Ford has all but said that they will subsidize the parts to keep the cost down. But how long will they eat those costs is going to be the question. Then you have to ask is GM going to follow suit? I'm test driving a Jeep Unlimited but will most likely order an Eco - diesel Ram as the insurance on a Jeep (comp/collision) is over $300 more then the Ram :E . I like to find out what the costs are before I buy. A whole lot smarter IMO then saying they screwed me after the fact.

Buy anything you want just make sure you have your questions answered before you put your hard earned money down.

BTW I read the first part of that article as Ford saying training cost will be picked up be Ford. Then later he says that it will be selecte dealers. Maybe I'm the only one that took it out of context?

Don

[v10superduty]

Perrysburg Dodgeboy wrote:
Sorry but that 10G is what Ford is willing to pony up for some of their dealerships the cost is more then 10G. Sounds like a vocational school would be cheaper for non dealers.

Still going to cost more to insure.

Don

Don, it appears you just can't ever say you were wrong or misunderstood...:h
There WAS no contradiction, you just read it wrong or misunderstood man.
Now you go on to your next silly argument?

Do you really think your post will sway someone to bypass an aluminium body truck in favor of "your" brand?
Which by the way will eventually follow suit if they are still around..:W

Remember how Dodge/Ram/whatever they were called then, pushed that they did not use DEF in their diesels a couple years back? They claimed that was an advantage even though they suffered worst fuel economy. NOW? They are using DEF!

As I said before Don, you are the greatest fan FCM(?) has on this forum and its kinda fun reading your posts.. SOMETIMES