Is the A2 green?

lyndonbuck

Member
Hello there, just wanted to try and get some A2 owners feelings as to whether or not their car is environmentally friendly. I'm not interested in the petrol/diesel thing, just the whole concept of the A2. I'm asking as I always use the A2 as the antithesis of my other car (1989 BMW M3) when people talk about green motoring (ie is my new A2 more or less damaging to the environment than my old M3). My initial thoughts are:

1. Aluminium body - light weight but high embodied energy in manufacture plus long term fatigue issues = bit of disaster or success? What about repair costs as the ali ages?

2. Better to keep an old car for ages rather than buy new? I think its about 30% of pollution is caused by making a new car, 70% in use, so what is optimal time to keep?

3. Was green an issue when you bought your car?

I have found a reference to the initial Audi brief for the A2 and green certainly wasn't high on the agenda then, but prestige certainly was.

I'm using this as a case study for some of my students so would be interested to hear your views. I am using some information that I have "gathered" from some other threads on this forum too so it would be good to see users real views as to how green they think they are having purchased an A2.

Thanks
 
I remember reading about the energy consumption of producing a car vs the energy in use and the conclusion I drew was that the best thing I could do was to keep the car as long as practical, I service it regularly so it should retain its low CO output.

As for the Alu, from what I have read Al takes 400% more energy in production than steel but only 5% of the production energy to recycle where steel requires 25% of its production energy to recycle.

Roughly the steel would need to be recycled 12 times before it used the production energy of the Aluminium, factor in the slight weight benefit in fuel consumption terms and the lack of repairability of the aluminium and I reckon modern lighter steels are probably more environmentally friendly.

Long and short, like the Pious the A2 probably isn't that green over it's full lifecycle and the best thing I can do for the environment would be drive slower and keep it longer.
 
The A2 was built for the following reasons

Prestige. Audi needed to differentiate their models from lesser VW's, Skoda's and SEAT's. They all use shared parts. In comparison to the development costs of engines, electronics etc a different body is not so expensive relatively. So the choice for aluminium was commercial.

Know how. Audi wanted to understand how to cost effectively build aluminium bodies in volume. No the 13-15K of the A8, but up to 100K.

Safer to do it with a new model than face consequences of destroying the image and profits of the successful A4 or A6.

Is the A2 green. Not really, just a step on the way. Look at the current 5 series. That is innovative in the use of aluminium and steels. Save weight where there is most benefit. Will BMW follow that up is the one question to ask your students.

By the way aluminium cashes better than steel. It's true! Easier for the engineers to predict.
 
I have an article from a recent What Car that tried to work out the life cycle environmental costs of cars. It came up with the Jeep as being the most environmentally friendly due to low energy cost of production. A2 not on the list (although there is a photo of someone filling up a light blue one!) The conclusions are surprising and I think suspect. I did buy mine with the environment in mind but as I brought second-hand I am thinking, fuel usage, recycle costs and that as no rust it could stay in use along time subject to spare availability.

A8 was in position 91
11 MX 5
17 BMW 330
23 A4
37 A3
48 Range Rover Sport
66 Aston Martin DB9
73 Honda Civic Hybrid
74 Pruis
90 A6
91 A8
92 Audi allroad
96 Maybach

Does that help. Could scan the article if you needed it.
 
Thats interesting, I do know that once you look at the whole life cycle of products it gets very complicated - a paper cup and plastic cup work out about the same, as do disposable nappies and washable ones - so I guess a lot of this depends on how accurately the car manufacturers calculate emissions etc. I have just read in Autocar (1st November issue) that some car industry experts are now saying that diesels could be producing more pollution than Lamborghinis (a Lamborghini Murielago produces the same CO2 as five Ford Fiestas) so it seems that no one can quite make up their mind on what is good and what is bad.
I have always believed - like Aikon - that keeping a car for a long time is a good thing, but I recently went to a lecture where it was stated (and I don't know how accurate this is) that the current Fiesta produces only 5% of the air pollution of the first Fiesta 20 odd years ago. I dread to think how much CO2 my 17 year old BMW produces.
Thanks for the replies so far - please keep them coming.
BattyB - if you could scan the article that would be great - I don't know if you can stick it on here, if not I'll send you my email, thanks
 
By the way I completely agree about the parts availability issue - I can get virtually any part for my BMW (which has been superceded by 3 newer models now) next day from Germany, right down to seat cushions, and I wonder whether that will be true for the A2, hope so.
 
20 November 2001
“AUTOCAR ENVIRONMENTAL AWARD 2001” - AUDI A2 1.2 TDI RECEIVES ENVIRONMENTAL AWARD

INGOLSTADT, Germany - Progressive technology, extremely lightweight construction and outstanding environmental compatibility are, according to Autocar, one of the leading British motoring magazines, the characteristic features of the Audi A2. At the traditional annual presentation of its “Autocar Awards”, the magazine today presented its “Environmental Award 2001” to the A2 1.2 TDI for its extremely low fuel consumption.
The Audi A2 1.2 TDI with its 3-cylinder TDI engine is the 3-litre version of the Audi A2. Delivering an output of 45 kW/61 bhp, it accelerates from 0 to 100 km/h in 14.9 seconds and reaches a remarkable top speed of 168 km/h. At the same time it achieves an average MVEG fuel consumption of just 2.99 litres of diesel per 100 km.

At a test drive performed by international motoring journalists back in the spring, the experts achieved consumption figures of between just 2.12 and 3.0 litres per 100 km, despite driving at considerable average speeds of around 70 km/h.

In the A2 1.2 TDI Audi offers the world’s first five-door three-litre vehicle. Its unique fuel economy is the result of consistent improvement on the already very economical standard A2 models. Aerodynamic finish, perfected lightweight construction and, finally, the 1.2-litre TDI engine with an automatically controlled manual gearbox: these are the most important prerequisites for excellent fuel economy coupled with distinctive driving pleasure.

Last year, incidentally, Autocar presented its hotly contested “Designer of the year Award” to the Audi designers Derek Jenkins and Luc Donckerwolke for the design of the A2.
 
from a full lifecycle perspective:


Aluminum is produced first by the chemical refinement of bauxite, impure alumina, to pure alumina. Four tons of bauxite give 2 tons of alumina — eventually producing 1 ton of aluminum.

The pure alumina is reduced by molten salt electrolysis, using a fluoride salt to form a molten bath with the alumina. Carbon anodes are consumed in the process causing the emission of CO2, but there are also some emissions of perfluorocarbon (PFC) gases such as CF4 and C2F6 caused by process excursions. There has been significant improvements in control of the electrolytic process in recent years, still continuing, which has resulted in a 47% reduction in PFC emissions between 1990 and 1997. While the total amount emitted is small, these gases have many times the effect of CO2 as greenhouse gases.

Of the electricity consumed by the aluminum industry in smelting, over 50% is hydro generated. It is the other generation of power which is the other major source of greenhouse gases. Primary aluminum supply will be able to meet all automotive customer needs with the power mix for smelting projected to be 56% hydro, 31% coal, 8% natural gas and 5% other in 2004 and beyond — virtually unchanged from today.

The bottom line is that the overall worldwide average emissions are 14.3kg of CO2 equivalents per kg of aluminum for primary smelter metal.

…..BUT



Another of aluminum's valuable environmental benefits is its unique recyclability. In many of its product applications, studies have shown that aluminum has exceptional performance with respect to other materials when the life cycle effects of recycling are taken into account.

An important key to this is the energy savings associated with aluminum recycling. As this slide shows, the energy required to recycle the metal is only 5% of that used to produce aluminum from raw materials.

Most of the energy used to produce primary aluminum is electrical energy for the smelting process, which, in effect is an environmental investment. The energy is embedded in the metal and therefore available to used over and over again, which is why we call aluminum the "Energy Bank."

And not only does recycling reduce energy consumption, it also saves 95% of the greenhouse gases associated with primary production.



Having obtained our base aluminum, whether primary or recycled, we need to add in the emissions arising from conversion to its final state — sheet, castings or extrusions.

These are indicated here, as follows:

For sheet, we add only 0.8kg CO2 equivalents per kg to the 14.3 we started with to give 15.1. — I should mention here that, for the sake of brevity, my slides will all read CO2, but what I am really talking about are CO2 equivalents.

For secondary sheet we also add 0.8 kg of CO2 equivalents, but to just 0.7kg of CO2 equivalents that recycled metal emits, totaling only 1.5 kg per kg of aluminum.

Similarly for extrusions and castings

Here, then, is the real bottom line. Taking into account the typical mix of sheet castings and extrusions for today's cars AND today's mix of primary and secondary, we arrive at 7.18 kg of CO2 equivalents per kg of aluminum.




And now, in the final portion of my talk, let me bring all of this data to a conclusion in order to explain the environmental benefits, the pluses if you will, of using aluminum in automobiles.




Having shown how much CO2 equivalent is on the debit side, so to speak, for aluminum, now let us consider the credit side — the benefits of its use.

First of all — how much weight does aluminum in the car save?

Here we see some examples of specific weight savings.

Overall, the weight savings achieved are around 50% versus iron and steel. Or in other words, 1 kg of aluminum can replace about 2 kg of steel or iron in most automotive applications.




How does this weight saving translate into fuel savings?

The consensus from the auto industry is that every 10% weight saved yields 5 to 10% fuel savings — without compromising size or safety, and while providing improvements in driving performance and end-of-life value.

For the purpose of the calculations to follow on the next few slides, let's call it a 7% fuel savings, which we believe is very conservative by the way.

The actual figure we use is 0.46 liters per 100kg mass saved per 100km traveled (or .000046 liters per kg per km)

For every litre of fuel saved we take the, I think, reasonable figure of 2.85 kg of CO2 per litre of fuel.

Before I get into my worked examples, it is worth noting that, through all the many steps in these assessments, assumptions have to be made. I have put together a list of all these assumptions in the paper handout — I encourage you to analyze them and come up with your own conclusions on the overall benefits that I am claiming. Put your own assumptions in. I guarantee that you will show a sizeable CO2 credit at the end of the car's life



So, now we get to the fun part, where we take all of the preceding and work on three cases.

The first one is for today's typical car in North America:

It contains 113 kg of aluminum, replacing some 226 kg of iron and steel.
The environmental "burden" for the aluminum is 811 kg of CO2 equivalents. (113x7.18)
The CO2 emissions from 226 kg of ferrous would be 407 kg. (226x1.8)
The net "burden" for aluminum is 404 kg CO2 equivalents. (811-407)
Fuel saved for 113 kg weight saved would be 1004 litres (113x0.000046x193000) over the 12 year 193,000 km life.
CO2 savings from this fuel saving is 2861 kg (1004x2.85)
Net benefit over the life of the car 2457 kg CO2 equ. (2861 - 404)
Crossover time to zero net CO2 is about 20 months

I have plotted this all here assuming linear annual mileage accumulation.



The next example — Case 2 — Here we are looking, actually at the GM Olds Aurora with 204 kg (450lbs.) of aluminum.

The same process as before — in this case, more aluminum simply means a bigger deficit on day 1, but also a bigger "credit" by the nominal end of life — some 4433 kg of CO2 equivalents savings in this case compared to the all-ferrous version.

So this could be looked at as "the more aluminum substitution, the greater the CO2 credit." The crossover in this case is the same at 20 months.

204 kg of aluminum content, replacing some 408 kg of iron and steel
The "burden" for the aluminum is 1465 kg of CO2 equ.(204x7.18)
The CO2 emissions from 408 kg of ferrous would be 734 kg (408x1.8)
The net "burden" for aluminum is 731 kg CO2 equivalents (1465-734)
Fuel saved for 204 kg weight saved would be 1812 litres (204x0.000046x193000) over the 12 year 193,000 km life.
CO2 savings from this fuel saving is 5164 kg (1812x2.85)
Net benefit over the life of the car 4433 kg CO2 equivalents (5164 - 731)



Case 3 is somewhat different.

Here, we are considering what we would call a full AIV — an aluminum intensive vehicle, where all of the structure and all of the skin is aluminum.

Obviously there is now even more aluminum, 340 kg (748 lbs) but now we assume that the weight savings are a little less (only 45% for the structure) and that the structure material is all primary not secondary. Rather than 40% prime.

This simply reflects the fact that there would not be enough scrap available at least until these vehicles start coming around for recycling — 12 , maybe 15, maybe more years later.

In this case, the lifetime "credit" is even higher at nearly 5000 kg, 5 tonnes.

And would be higher with a longer lifetime.

So, in this case, the CO2 debit is 3946 kg (190x15.1)+(150x7.18)

Take away 1162 kg CO2 for the 645 kg of ferrous replaced (645x1.80) = 2784kg

Fuel saved over 12 years = 2713 litres (645-340)x0.000046x193100

CO2 saving from fuel saving 7733 kg (2713 x2.85)

Net "credit" is 4949 kg CO2 ( 7733-2784)

Time to "CO2 net zero" = 52 months or 70,000 km (43,000 miles) of driving.




Hopefully, I have illustrated for you the merits of lightweighting with aluminum, but just before I wrap up my presentation, I'd like to show you a new emerging technology that will enhance the recyclability of automotive aluminum.

This new technology is called "LIBS"— laser-induced breakdown spectroscopy — and it is being developed to allow separation of aluminum shreds by alloy.

Already today 95% of automotive aluminum is recovered by disassembly or by separating aluminum shreds. But most of that recovered metal goes back into castings and is somewhat downgraded.

This new technology will allow full closed-loop recycling of the wrought alloys — that is to recycle them back into the same products from which they came, as we do today with aluminum beverage cans.

The idea involves shredding as per normal, followed by shred shape recognition and laser OES of each shred such that it can be diverted into the appropriate bin.

LIBS is being developed by Huron Valley Steel in Detroit with support from the Auto Aluminum Alliance — an alliance of automakers and aluminum companies.

To see the benefit of this … If we now put 60% recycle into the AIV in the Case 3 example we just saw, we would increase the CO2 "credit" per car to 6454 kg and reduce the "crossover" to just 20 months.




The conclusions, then;

Aluminum can replace iron and steel in automobiles with weight savings of 45 to 50% with gains in performance and no loss of safety.

Fuel savings deriving from the weight saving balance the net CO2 emissions typically within the first few years of vehicle service. And, over the life of the vehicle, a substantial CO2 "credit" is created.

The advent of alloy sorting from end-of-life vehicles will lead to closed-loop recycling of auto aluminum and even greater environmental gains from the use of aluminum in vehicle construction.

And lest you think that this is just an aluminum industry sales pitch, let me assure you that we are not the only ones that recognize the valuable contribution that aluminum can make...



Will Boddie, VP Research & Vehicle Technology for Ford Motor Company, recently stated ...

"High-volume application of lightweight materials, including aluminum, is a key to increasing fuel economy and decreasing emissions to address global environmental concerns."
 
True weight savings acheived through applying aluminium over steel are in the 30% to 40% range and although I can accept that in some circumstances 50% is acheived. I used to sell aluminium to car companies and thier tierd suppliers for a living, so I know. The Alcan paper paints the optimistic view, it is to be expected they are promoting their technology and fighting a battle to sell more material.

However, if it what is stated is so great why are there not more 100% aluminium cars on the road today in the sector of the A2 or A4 class? The answer is complex but straight forwards. Yes, aluminium yields weight savings in many areas of the car but often is too expensive for the car manufacturer to use, investment needed is often high and customer returns low. We, the buying public, are prepared only to pay so much and are not really that concerned how a car is made or what out of. Yes we want maximum fuel economy but often will baulk at the price. Look at the real take up of the A2. If it had been a rip roaring sales success with demand meeting or even exceeding Audi's targets then I'm sure that A2 Mk2 would already be available and being sold now. But it wasn't, Dr Moore states 50K -60K per year made, 20K is nearer the real figure. The problem is simply cost, the A2 new was too high. The cost of motoring is too low with customer price resistance and strong competition especially nowadays from low cost countries prevents most car producers going completely down the aluminium route, yes, weight saving is really important to them but they will only pay so much. In fact it is costed in £, $, and Euros per kilogramme saved and if a proposal come in above that it will only be in exceptional circumstances will a part outside of this cost target range be adopted. But much has been achieved with alloy closures, doors, bonnet lids etc and the adoption by many luxury manufacturers of aluminium axle frames.

Dr Moore, a brit by the way, makes no mention of joining of aluminium. It is difficult. Unlike steel aluminium cannot be consistantly spot welded due to the oxide always present. Spot welding may be cheap and cheerful but it is also highly effective. Alcan have patented a method of rivit bonding. This is used on the XJ and now XK Jaguars aluminium monocoque bodies. Think of the production route of a) producing and shipping the rivets b) the logistics and supply chain issues and c) the extra cost over the simple spot weld. Audi, we know well, chose the space frame route. Similar problems faced by both companies are the high spring back of aluminium for forming and achieving consistant parts leading to issues concerning needed narrow gaps for welding, the A2 is laser welded and despite the majority of the Jaguar being riveted there is also areas where welding was selected. Steel can be welded even with wide uneven welding gaps. It is sadly really an easy hands down win for steel in the processing stakes. It is the processing costs of aluminium which is preventing the use of more wrought aluminium in our vehicles today.

But, but, but...man simply cannot go on poluting the environment as we currently do driving ourselves to that out of town shopping centre or to shools . Vehicle emmisions must be reduced, weight saving must be increased. Steel and aluminium will jointly play a role. Like aluminium steel is developing new alloys to save weight. They have a vested interest to do so. Steel has the processing advantage, they can acheive fantasticly high levels of strength but only in the last few years has a big drawback revealed itself. The Mass Law. The Mass Law states "halve the mass, double the noise". In other words to make the vehicles bearable, the driver and his passengers not to be deafened extra sound insulation has to be added and all of what goes with that. More environmental, logistics, supply chain, effort, recyclability AND weight. A lot is going into more lightweight and friendlier sound insulation. But with aluminium more mass is used anyway to acheive the funtionality of the part over steel so less insulation can be used. In short it is not possible to optimise the full potential of steel in terms of weight saving.

So while I am strongly in favour of aluminium it is necessary to remain realistic in what can be acheived at a cost and therefore price that customers are prepared to pay. Let's face it nobody I've read on this site has been happy to spend money with Audi dealers. Why should it be any different in the future?

I worked in the aluminium industry for many years working together with the auto industry working on the lightweighting of cars so have a personal experience of these issues. I tell you all again that the current 5 series using aluminium front end attached to a steel body is clever and can as a concept be developed further. And don't forget magnesium...

..and I completely agree with ULP. In the end we will all have to pay more to enjoy our cars, in the products themselves, higher fuel costs and road charging. I like Land Rovers. They use lots of aluminium!
 
I think the car industry can learn from the cycle industry here.
As a mountain biker I remember that 10 years ago aluminium frames were a fortune. Now my sons £140 saracen bike has an alu alloy frame. The strength to weigh ratios of alu are without dispute. You can get very exotic alloys in any material you like, but cheap recyclable alu is in common use in bikes. With a car its all about moving mass, so use of aly and PP body panels can save a lot of weight and therefore fuel over the vehicles lifecycle. There is no magic bullet and I believe it is key to separate a car into three factors:
1. fuel efficient means of propulsion.
2. mass of vehicle
3. amount of use the damn thing gets (in many cases this outweighs the CO2 used to make it).

So we all should be driving light cars with efficient engines and using them less than we do.
Personally I would love to have a culture of cycling for commuting like they have in many continental countries, but I fear the fat "i'm a celebrity" watching slobs of this country would never subscribe to physical exertion.
 
Unfortunately cars are much more complex than cycles and there's a lot more to it to put all the bits together. But again I agree with CHB's sentiments. Having said that I'm not to keen to get on my own bike, the hills are far too steep for my aged legs!
 
Mark,
perhaps I should have clarified my mention of progress to talking specifically of cycle frame construction.
For example, my 1991 £350 Marin Palisades had a Cr-Mo steel frame and weighed a tonne. Now a similar sum of cash buys a hydroformed alu frame that weighs in a a lot less.
Of course a car is more complex than a bike, but I would say in engineering terms it is different only in scale, not in difficulty. In fact there is more pressure to save weight on a bike than on a car as this is a major selling point. Sudden catastrophic failure of a bike frame is just as disastarous as failure of a cars component, so the engineering rigour is the same.
Of course every other bit of bikes has come a long way in this time, but I believe that cost effective manufacture of alu car compontents should be here today.
 
My aluminium bike frame has a big sticker on it that warns the rider to check for cracks on the frame each time they ride, and I for one have broken an aluminium bike frame (mind you I do eat a lot of pies). I also have a lovely steel framed bike which weighs less and will probably last a lot longer. The bike industry is now moving away from aluminium back to steel as well as all the exotic stuff. As for cost effectiveness, I was under the impression that the A8 chassis cost as much as the selling price of the whole car to make, much the same with the Honda NSX - so they were used as learning vehicles, with the A2 much more refined than the A8 in terms of design etc (thanks to Mark Brigg for the Audi spaceframe info).
 
As I wrote earlier the future for cars is multi material. What is used will depend on the demand - image, concept, cost and market in what the customer will pay or be forced eventually by legislation to pay.

As far as the materials used themselves it revolves round the concept. Bikes are moving back to steel. I'm not surprised as there are some steels with fantasticly high mechanical properties - Lyndon your students need to know that it is the proof strength that is the important one to whatch as this gives the stiffness in the finished part- but it all comes down to the ratio between fatigue life and stiffness. Bike frames, like train structures usually utilise straight structures. OK there are some formed i.e. bent parts but these are usually limited. Cars on the other hand have few straight parts. The A2 actually is different as Audi tried to design as many straight structural parts as possible due to the problems of bending extrusions consistantly. Even then most structural parts were hydroformed to enable the welding of the frame together. That was down to the choice of Audi and its aluminium partner of extrusions over alternative aluminium semis such as sheet or cold rolled profiles or even seam welded tubes.

Lydon, no need to check your space frame for cracks in the welded zone. Bikes tend to use 2000 or 7000 series aluminium for the high strength properties. Unfortunately they also have serious issues with welding and cracks in the weld and affected heat zone. Many cheap older bikes sourced from China used 2000 series in the past and carry some risk. The 6000 and 5000 mainly used in automotive are perfectly safe!

CHB - there is still some way to go to solving all the joining issues yet as far as car companies are concerned. I know a lot about hydroforming and it costs 5 times more than conventional pressing. Its easy to slag off the car companies but the reality is that an awful lot of money has been spent and huge resources have been directed to finding solutions to the problem of reducing the weight of our cars. And we should not forget really how brave and bold Audi were in producing the A2. It really is a most remarkable little car in many ways advanced and not just in its construction.
 
lyndon, you are correct that there have been alu frame failures.
But there are also alu frames that have very safe working range.
Making a rigid bike out of Alu is tricky because if you build it safe to be strong then it can be very stiff to ride. But if you look at full suspension frames, these are nearly all alu structures. The alu lets you build very stiff light structures, and the pivots do the work of making it comfy.
I have several alu frames and have never seen a sticker warning for cracks....is yours a 1990's cannondale as they had a notorious spell!
Alu has an advantage over steel for rigid structures. I agree that steel frames are fab and long overdue for a comeback, but I doubt that the skinny doublebutted tubes on my "orange clockwork" have much of interest for the car industry. My sons alu saracen bike has more to teach as it shows that affordable alu is there.

Mark, I wasn't slagging off car companies, and I agree mixed materials are the future. Alu doors and tailgates with steel crumple zones?
 
Probably slightly off-topic, but I seem to remember that when the Lotus Elise started its life, didn't Lotus pioneer a technique of joining aluminium using a glue? Or am I confusing this with extrusions?

I defer to other's superior knowledge in this area!
 
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