[Jason]

LONDON (Reuters) -- To help reduce vehicle weight aluminum is becoming more important for German automaker BMW and its use of the metal has grown steadily in recent years, the company said.

Carmakers around the world are on a mission to reduce the weight of cars to promote fuel efficiency and aluminum fits the bill as it is lighter than steel and sustainable because it can be recycled.

"The most significant changes were the introduction of aluminum doors and hoods in some models as well as casted structural components," said Frank Wienstroth, who oversees BMW's communications on the supply chain and sustainability.

"The application of aluminum varies significantly between different models. As an example for a typical BMW premium car the new 5 series has aluminum parts totaling up to almost 20 percent of the vehicle weight," he said this week.

The world's largest premium car maker recently detailed plans to take its Five Series ActiveHybrid concept into full-scale production as early as next year.

Aluminum recycling rates in the transport sector are estimated at more than 90 percent. In the building sector the number is 95 percent and in packaging it is thought to be much lower at around 35 percent.

The average car weighs about 1,200-1,400 kg, containing around 500-700 kg steel, according to Jaguar Land Rover. Aluminum tends to be used in wheels and hoods.

Use of lighter aluminum also leads to other savings such as less wear and tear.

BMW earlier last week posted its best ever quarterly pre-tax profit, lifted by surging sales of luxury cars in China, the relaunch of its lucrative 5 series saloon and a weaker euro currency.


High strength steel

Steel is the most important material in BMW's "conventional" vehicles, accounting for about 40 percent of weight. BMW does not expect that to change over coming years.

But in the future, to make some of its vehicles lighter, steel will be substituted with lighter materials such as aluminum, plastics and carbon fiber laminates would continue.

"The lightweight strategies depend on the vehicle segment and the type of drive. In higher segments and for electric cars a more extensive use of lightweight parts is to be expected," Wienstroth said.

Higher segments is a reference to larger cars.

Electric cars are a big theme in a world currently focused on energy conservation and climate change.

BMW last year said it would launch a new class of environmentally friendly vehicles under its own brand, signaling that even premium automakers are ready to embrace electric vehicles as a mainstream product.

On the subject of lighter, higher strength steel, BMW said: "Regarding cost optimization in weight reduction the weight advantage of aluminum can be equalized by new steel characteristics at lower material costs."

Some automakers worry about using aluminum in their cars because of price volatility. Some say they could be persuaded if they could get long-term deals with producers.

Benchmark aluminum prices on the London Metal Exchange have ranged between $1,300 and $2,400 a ton since the first quarter on 2009 when markets started to fear economic recession could turn into a 1930s style depression.

Global consumption of aluminum this year is estimated at about 37 million tons.

Source: http://www.autonews.com/apps/pbcs.dl...#ixzz0w81Qm539 (subscription required)

[Year's_End]

Doesn't Audi incorporate far more aluminum in their models? I'm pretty sure that the new A8 weighs less than the new equivalently-engined F01, which is pretty sad.

[Bora20]

Audi A8 4.2L - 1910 kg

[nockenpaul]

Originally Posted by Nikkahtropolis

Doesn't Audi incorporate far more aluminum in their models? I'm pretty sure that the new A8 weighs less than the new equivalently-engined F01, which is pretty sad.

Well, the A8 has an aluminum spaceframe. But it's not that much lighter than you would expect.

A8 3.0 TFSI: 1905 kg
740i: 1935 kg

A8 3.0 TDI: 1915 kg
730d: 1940 kg

The A8 weighs less than the F01, but it's not significant. (But it has to be mentioned that the A8 has 4WD.)

[x838nwy]

Al is slightly over-rated in terms of the weight reduction it can achieve. As a material is very low in density compared to steel, but to make structures (chassis) with a similar rigidity as steel requires a.)some very expensive technologies, and b.)more material so the overall weight reduction is not as large as people expect. (As invariably, someone has to say that it's actually cheaper to make some parts in steel instead.)

One of the biggest problems come from where aluminium needs to form a strong and rigid joint with steel. The joints are usually very heavy and expensive since they can't just simply be welded together. This tends to limit the use of aluminium to bolt-on panels (where weight saving over steel is very small). Only recently have mainstream cars used aluminium as structural members. (I wouldn't call Lotuses and Aston Martins mainstream, btw.)

I do hope they develop the technology. Jaguar have been making cars with a lot of Al and so has Audi and BMW has been matching them in weight while using steel. I wonder what BMW can do given a few years with the technology. May be the next M3 will be lighter than the current one for a change.

[bavarian19]

With the new Carbon facility opened up, how long will it be until we see an entire CF body?

[Oulixes]

The article makes interesting claims, which may be true but hardly significant. To make the article less fluffy, at least an attempt should be made at comparing the use of aluminum in cars of similar class.

[M3_WC]

Originally Posted by nockenpaul

Well, the A8 has an aluminum spaceframe. But it's not that much lighter than you would expect.

A8 3.0 TFSI: 1905 kg
740i: 1935 kg

A8 3.0 TDI: 1915 kg
730d: 1940 kg

The A8 weighs less than the F01, but it's not significant. (But it has to be mentioned that the A8 has 4WD.)

Like you said, considering Audi's heavy quattro system, it does way a lot less.

[WilliamE92]

Call me when BMW gets the M3 down to 3400 ish

Seems to me they're using more aluminum so they can load the car up with more electronics while still keeping it under 2 tons

Hopefully this means lighter cars all around!

[Tallest]

I guess carbon fibre is so massively more expensive that they still dont make cars from it on mass scale.. cant see any other reason why, because CF to me makes so much more sense. Some 2l turbo 4 CF car will probably humiliate similar sized average sedan made of steel and al.

[BMW269]

BMW's and Audi's AWD system weight both depending on models, between 80 and 100 kg more. Here a comparision of 3 Series and A4. They are very close.

BMW 335i: 1610 kg
BMW 335xi: 1690 kg (+80)

BMW 330d: 1610 kg
BMW 330xd: 1710 kg (+100)

BMW 320d: 1505 kg
BMW 320xd: 1600 kg (+95)

Audi A4 2.0 TDI: 1540 kg
Audi A4 2.0 TDI Q: 1635 kg (+95)

Audi A4 3.2 FSI: 1605 kg
Audi A4 3.2 FSI Q: 1685 kg (+80)

Audi A4 3.0 TDI Q: 1730 kg

New X3 is 25 kg lighter than old X3, yet the new one is better in all ways. So new 3 Series will also be lighter. 335i weighs 1600 kg. The new M3 will be based on this car, so the new M3 will be lighter than 1600 kg, this means more than 50 kg lighter than actual M3. Note, M3 GTS is 70 kg lighter than M3, and has 450 HP, new M3 will weigh as much as M3 GTS but have more torque, so this mean much faster accelerations. I just hope it will keep high end power, but the M1 will tell us this.

[leemik]

Originally Posted by research

I guess carbon fibre is so massively more expensive that they still dont make cars from it on mass scale.. cant see any other reason why, because CF to me makes so much more sense. Some 2l turbo 4 CF car will probably humiliate similar sized average sedan made of steel and al.

I read once that Ferrari is hesitant to go all carbon fiber because they are unsure of the long term reliability of going all CF on a car vs proven elements like aluminum.. so maybe everyone else is taking a cautious approach as well, introducting CF slowly in non critical components.

[sb335is]

No thank you. My moms C350 has aluminum body panels
1) the trunk feels tinny as shit when you're closing it
2) the hood, doors , and trunk pressure dent like that. 500 bucks per panel to fix one dent.

[x838nwy]

Originally Posted by twoturboz

No thank you. My moms C350 has aluminum body panels
1) the trunk feels tinny as shit when you're closing it
2) the hood, doors , and trunk pressure dent like that. 500 bucks per panel to fix one dent.

If you get appreciable dents, aluminium is not fixable as it yields and stretches more easily. That's one bad thing about aluminium body panels. But I guess since hardly anybody bothers repairing anything these days, it's not too much of a problem.

Originally Posted by leemik

I read once that Ferrari is hesitant to go all carbon fiber because they are unsure of the long term reliability of going all CF on a car vs proven elements like aluminum.. so maybe everyone else is taking a cautious approach as well, introducting CF slowly in non critical components.

McLaren seem to think otherwise (at about 1:55 http://www.youtube.com/watch?v=y5Ict...eature=channel ). The real problem with using CF is manufacturing. Engineers are nowhere near as proficient with it as they are withe steel or aluminium. It's like sitting Da Vinci down in front of Photoshop. To make a car in full cf a manufacturer would have to develop/invent totally new techniques and learn as they go along. This will costs millions - not to mention all sorts of reliability problems they might run into. I seem to remember that the a-pillar for the Lexus LF-A was woven on one of two 3D looms in the world http://www.youtube.com/watch?v=l4DLr8qHliI just goes to show the complexity involved if you really want to engineer CF properly.

[manicm]

BMW is actually abandoning aluminium, favouring high-strength, low weight advanced steels.

Abandoning aluminium has not proven wise however - the 5GT weighs a truck-like 2 tons, not far off an X6 actually.

[ring007]

skip aluminum and focus on CF.