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Aluminum Use in new European Cars up 2.6x since 1990; Weight Reduction Yields Fuel Savings of 1 Billion Liters

A new study determines that the amount of aluminum used in new European cars has risen from 50 kg in 1990 to 132 kg in 2005 and is predicted to grow by another 25 kg by 2010. In 2005 two million tonnes of aluminum components were put on European roads in new passenger cars. The achieved weight savings will lead to an annual fuel saving of 1 billion litres and will save roughly 40 million tonnes of CO2 emissions over the lifespan of the vehicles, according to the study.

The study by Knibb, Gormezano & Partners (KGP) in cooperation with the European Aluminum Association (EAA) includes data from automotive companies and suppliers, EAA member companies and past data from KGP. The study is based on the analysis of the 15 million cars produced in Europe in 2005 and investigates 20 body components, 17 chassis and suspension components and 25 powertrain components.

The study focuses on different aluminum semi-materials—castings, extrusions, forgings and sheets. In the car body the largest quantity of components made from aluminum are air conditioning systems, hoods, bumper beams and steering columns. aluminum parts in the chassis and suspension section of the cars are mainly wheels, suspension arms and steering components.

Cylinder heads, cylinder blocks, engine covers, pumps and radiators represent the majority of aluminum components in the drivetrain of new cars. Today, a growing amount of aluminum is being used in particular in closures, body structure and chassis applications.

Europe is leading the way in innovative use of aluminum in cars. As 100 kg of aluminum on a car can reduce CO2 emissions per kilometre by 9 grams, and even 10 grams if fuel production is considered, aluminum as material for lightweighting cars has a clear advantage. With the continual introduction of new technologies delivering further advantages in the design and manufacturing processes the trend to increase the amount of aluminum per car will continue. aluminum will certainly play an important role in future generations of sustainable cars.

—Roland Harings, Chairman of the EAA Automotive Board

The European aluminum Association, founded in 1981, represents the European aluminum industry from alumina and primary production to semi-finished and end-use products, through to recycling. The European aluminum industry directly employs about 236,000 people.

The calculations in the study are based on the following assumptions:

  • Car lifespan of 200,000 km; yearly vehicle kilometers traveled 15,000 km.

  • 0.35 liters of fuel saved per 100 km per 100 kg weight reduction.

  • 1 kg of aluminum provides 1 kg of lightweighting.

  • 2.835 kg of CO2 per liter of fuel, as the mean value for gasoline and diesel, including pre-combustion (i.e. CO2 generation for fuel production)

  • 2.455 kg of CO2 per liter of fuel, as mean value for gasoline and diesel, excluding pre-combustion.


Shaun Williams

Not sure if they included emissions of CO2 from production of Aluminium (the "determines" link is not working Mike).

Some quick and dirty web research shows;

If the Al was made here in coal burning Australia (which a lot of it is) I think those 2 million tonnes of Al would = 20-30 million tonnes of CO2 as compared to about half that for steel production, despite that there seems to be a respectable net gain when using the lighter Al in cars.

The real plus is recycled Al, supposedly it only needs 5% of the energy to get it back into "new" products.


You are very correct Shaun.
The story is similar to the endless hydrogen vs oil debates where people forget about the energy required to make the hydrogen.

Quite possibly the future may be carbon in the form of carbon fibre and its many brothers the carbon nano tubes and various nano structure designs. Virtually the whole vehicle can be made of carbon.
The stuff is very light by nature, but it can be made impossibly hard and impact resistant or flexible and soft. The chasis could be carbon as could the engine/fuel cell, fuel storage tank, lubricant and any fabric like material within the vehicle. Even the tires can be manufactured of the stuff.
And when you recycle your car it gets liquified completely into one element by some process, ready to be turend into something else. I could be wrong, but it sounds too elegant to be rubbish.


As I understand it carbon fibers are held together by epoxy resin to make panels, (a petroleum based product), so it's not actually only carbon.


Out of interest, I loaded a Toyota Prius simulator with the following data points:

Ambient Temperature: 70°F or 21°C
Wind: None
Barometer: 30.03 in/Hg or 101.7 kPa
Relative Humidity: 85%
Elevation: 410 ft. or 125 m
Vehicle Speed: 70 MPH or 112.65 km/h
Total Vehicle + Cargo Weight: 3,100 lbs or 1,406 kg

The simulator shows that the Prius would get 49.21 MPG(US) or 20.92 km/l or 4.78 L/100 km

I then removed 500 lbs or 227 kg from the vehicle. In reality, it would be very difficult to find enough steel components that could be converted to aluminum or aluminium to get a net savings of 500 lbs or 227 kg & almost puts this example into the realms of ‘unreality’ but, let’s take a look now at the fuel savings anyway.

Eff w/ normal weight............Eff w/ weight reduction
49.21 MPG.......................50.72 MPG
20.92 km/l..........................21.56 km/l
4.78 l/100 km....................4.64 l/100 km

So, on a 62.14 mile or 100 km journey this vehicle will save 0.038 gallons(US) or 0.11 liters with 500 lbs or 227 kg removed.

The article only uses 100 kg or 220 lbs reduction so, I will now adjust this commentary’s numbers to make them relative to the article.

A very important baseline in this article’s study states: “0.35 liters of fuel saved per 100 km per 100 kg weight reduction.”

The example I cite in this commentary indicates that the savings on a Prius would only be 0.05 liters of fuel saved per 100 km per 100 kg weight reduction.

This means that a very fuel efficient vehicle like a Prius only stands to save 14% as much whatever this article is using as a baseline vehicle fuel efficiency.

This tells us that it is far more beneficial to pursue CO2 reduction by using hybrid vehicle technology than it is by simply reducing a vehicle’s weight with aluminum or aluminium.

Harvey D.

Wayne: Does your program accounts for various (variable) highway speeds + 50% city travel + about 20% or 30% braking energy recouperation due to slow recharge batteries etc?.

At steady (70 mph) elevated highway speed, wind drag reduction may be as important as weight reduction but it is not so at lower speeds and in city traffic.

Rafael Seidl

Wayne -

bear in mind that the drive cycles used to calculate official fuel economy numbers all feature only moderate acceleration and no hill climbing at all. Yet those are the real-world situations where additional mass really does impact fuel economy. If you live in hilly terrain, consider buying the lightest car that meets your requirements.

Even so, aluminium, for all its advantages, is no miracle material in coachbuilding. In particular, Audi discovered the hard way with its now-discontinued A2 that it's hard to achieve the necessary geometrical tolerances using aluminium sheetmetal. The hood and trunk lid are more forgiving parts in that respect than the doors and fenders, which often require expensive manual post-processing to meet spec.

The material is great for many drivetrain parts and housings, including the suspension and wheel rims. It also performs well for certain parts of the monocoque chassis. For these applications, the metal is typically cast or kneaded (e.g. forged, extruded or hydroformed).

Porsche and others (e.g. BMW) have experimented with carbon fiber body parts in series production vehicles. However, the EU mandates that vehicles be designed for recycling. Given the still sky-high cost of carbon fibers, that means dissolving the matrix and recovering the fibers. The process tends to shorten the fibers, making them unsuitable for the same application. Therefore, in spite of the undoubted technological advantages of composites for small production runs, their intensive use remains limited to race cars.

This would change IFF carbon fibers were to become cheap enough to permit the incineration of composites for electricity generation at the end of their life. Lignin, a waste stream in wood processing, is a viable feedstock though it is hard to handle as it is a natural glue. Either solar ovens and biogas could be used to provide the energy required for the high-temperature pyrolysis process. Another "carbon-neutral" source of process energy would be the vast amounts of associated gas that are flared off near oil wellheads, mostly in Russia, Africa and the Middle East.


Rafael Seidl,
Perhaps we can just bury the old carbon fiber panels, as a form of carbon sequestation. Another possibility is to sort and store them, until new methods for recycling arrive. A final possibility is to recycle the carbon fiber, from old high end products, in low end (and low strength) products (ie non structural cosmetic pieces).


Could you please link to the study? There is no link to follow from the underlined word "determines" in the first line. Thanks.



Using carbon nanotubes in the assmebly of a vehicle structure is further off than sustainable fusion reactors. Right now carbon nanotube product costs are 10x the value of gold by weight ($600 for an ounce of gold and $6000 for an ounce of carbon nanotubes).

Wayne Brown

Hi Harvey & Rafael,

First, in answer to Harvey; yes, aerodynamics does play a big part in the formula. At 70 MPH the aerodynamic drag consumes 10.75 kW or 13.51 horsepower. At 25 MPH it consumes 0.46 kW or 0.62 horsepower.

At 25 MPH a reduction of 100 kg or 220 lbs will increase the MPG from 99.14 MPG 101.57 MPG. This constitutes a 2.4% gain in MPG whereas at 70 MPH we are only getting a 1.3% gain. However, even though it would appear that I am saving significantly more at 25 MPH, I am, ironically, still saving exactly 0.05 liters of fuel per 100 km per 100 kg weight reduction. Again, hybrid technology wins hands down in slow speeds also when it comes to reducing CO2.

The simulator does take into consideration high voltage battery SOC (state of charge) averaging for such speeds. The Prius actually does better in city mileage than highway so, much of the gain that would otherwise be available in 'normal' or non-hybrid vehicles does not apply in a series/parallel hybrid like the Prius.

In response to Rafael's comments: The Prius pulls away from a dead stop using mostly electrical energy it has captured from regenerative slow-downs & braking. Even when the ICE or internal combustion engine comes to life when pulling away from a dead stop, it generally contributes less than 15% of the motive forces up to 20 MPH so, most of the energy used to start out is from energy captured via regeneration while slowing down or braking.

As for mountains; most Prius owners have found that they do not lose any mileage in mountainous terrain but, actually come out slightly ahead of flat terrain MPG. Many opinions have been offered over the years on this & much has been opined on this throughout most of the groups but, overall it has mostly to do with downhill regenerative energy capturing. I have added an extra 18 Ah of high voltage battery for a total of 24.5 Ah vs. OEM of 6.5 Ah & seem to do significantly better in mountainous terrain than do my fellow Prius drivers.

All that said though, you are correct Rafael; we would need smaller storage batteries & less powerful engines in our hybrid vehicles if we were to make them with less mass. However, a whole lot less CO2 would enter the atmosphere if the same $ being spent on weight reduction by using aluminum parts were to be spent instead, in converting production lines to fabricate hybrids such as the Prius.


just think, they can recycle the cars after they're done using them, to make new light cars.

"You are very correct Shaun.
The story is similar to the endless hydrogen vs oil debates where people forget about the energy required to make the hydrogen."
just as a side note, kind of off topic but,
What about the energy required to extract oil from say, the oil sands, or else the energy required to turn oil into gas?


...and then what of the CO2 produced in the production of hybrid components versus a non-hybrid lightweight vehicle?

Wayne Brown

Patrick - The production of a hybrid vehicle does cost more in CO2 emissions. In the case of the Prius it must be driven 12,400 miles or 20,000 km to get to the 'break-even' point. After that its CO2 emissions average about 53% less than a comparably sized non-hybrid vehicle.

To be more clear on this; a comparably sized non-hybrid modern vehicle will require 53.80 tons of CO2 emissions for production & 100,000 miles of use. A Prius will require 28.47 tons of CO2 emissions for its production & 100,000 miles of use.

This means that the production & 100,000 mile lifetime of a series/parallel hybrid emits 47% less CO2 than a comparable non-hybrid vehicle.

If the vehicles were to have more than a 100,000 mile lifetime then the 47% less CO2 figure will continue to increment.

Shaun Williams

Yeah, the trick is to buy a used Prius and let the first owner do all the dirty driving. :-)

Of course this means that a second hand Prius should be worth more than a new one!

Rafael Seidl

Allen -

the EU directive requires that all combustible auto recycling streams that contain more than 11MJ/kg of energy must be incinerated for electricity production, unless it is technically and economically feasible to recover the materials.

As the law stands, burying composites would not be permitted. It's a moot point anyhow, since carbon fibers are still way too expensive for series production cars right now, never mind the recycling.

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