How light could a car be made?
Discussion
See a lot of moaning about cars being heavy things, which is to be expected as they are large and generally made of metal and stuff.
Latest was the RS4 Competition, apparently its nearly 2 tons, despite the text saying its 1770 including a 75 kilo driver, some serious rounding up going on there.
Cost issues aside, how light could that medium sized estate car be built and still have all the features, comfort, safety, performance etc ??
What is it that Audi is apparently doing wrong to end up with a car that weights 1715 kilos ? Which doesnt sound that ridiculous to me anyway.
Or is it just that is what cars weigh if you want 450 bhp, loads of luxury, not to die in a small bump and it last more than 5 years ?
Do we worry about weight too much on here for cars that arent actually needing to save weight ?
Maybe dont buy a luxury, high performance estate car if you want lightness ? its like buying a 13 tog duvet and moaning that you are a bit warm in bed, or age 8 underpants (Why, because you cant get XL Minecraft, durr !) and saying they are a bit tight.
How many who go on about lightness are light themselves ? See it on push bike stuff, hefty blokes discussing saving a few grams on a seatpost or something, does it matter ?
Latest was the RS4 Competition, apparently its nearly 2 tons, despite the text saying its 1770 including a 75 kilo driver, some serious rounding up going on there.
Cost issues aside, how light could that medium sized estate car be built and still have all the features, comfort, safety, performance etc ??
What is it that Audi is apparently doing wrong to end up with a car that weights 1715 kilos ? Which doesnt sound that ridiculous to me anyway.
Or is it just that is what cars weigh if you want 450 bhp, loads of luxury, not to die in a small bump and it last more than 5 years ?
Do we worry about weight too much on here for cars that arent actually needing to save weight ?
Maybe dont buy a luxury, high performance estate car if you want lightness ? its like buying a 13 tog duvet and moaning that you are a bit warm in bed, or age 8 underpants (Why, because you cant get XL Minecraft, durr !) and saying they are a bit tight.
How many who go on about lightness are light themselves ? See it on push bike stuff, hefty blokes discussing saving a few grams on a seatpost or something, does it matter ?
I'd say laziness but could be harsh. It's a bit like software bloating because it's easier than making the effort, which takes time and money.
I'm structural (aero) and a lot of time is spent optimising to ensure mass is kept as low as possible. This is probably undesirable for companies like Audi, who want to keep costs down as we're an expensive resource.
Also time to market is different for automotive so there's a limit to how much engineering can be done in a short time. Accountants also drive a lot of things nowadays and are constantly squeezing the engineering out.
Although bikes are a different matter due to the mass ratio. I've never faffed about saving grams on a bike when I'm 7x the mass of my bike. But in a car it's a different story as the difference between, say a Civic Type R and an Audi S3 is likely to be 200kg. So it can be done, just that Audi have different objectives (and German cars rarely have mass as one of them).
I'm structural (aero) and a lot of time is spent optimising to ensure mass is kept as low as possible. This is probably undesirable for companies like Audi, who want to keep costs down as we're an expensive resource.
Also time to market is different for automotive so there's a limit to how much engineering can be done in a short time. Accountants also drive a lot of things nowadays and are constantly squeezing the engineering out.
Although bikes are a different matter due to the mass ratio. I've never faffed about saving grams on a bike when I'm 7x the mass of my bike. But in a car it's a different story as the difference between, say a Civic Type R and an Audi S3 is likely to be 200kg. So it can be done, just that Audi have different objectives (and German cars rarely have mass as one of them).
Edited by Zero Fuchs on Wednesday 19th July 10:52
John_S4x4 said:
Yes, nice but not sure its a direct competitor for an Audi estate.Not sure its laziness, there is just so much packed in and all the manufacturers are broadly similar weight for the same class of car, all now 4wd in that class as well.
Arent Mclarens typically 1400/1500 kilos ? that a 2wd, carbon tubbed 2 seater, the Audi at 1700 odd doesnt seem that bad given 2 extra driveshafts, three more seats and a big box for carrying stuff.
John_S4x4 said:
I raise you Rob Barksfield’s PCD Saxon hill climb car.208kg wet. Seeing as we have mission creep and all that..Friends of mine built the engine for this.Pica-Pica said:
Believe me, car engineers do their damndest to keep the weight down. Only high material costs prevent that.
It doesn't seem that way with German manufacturers as they actively go out of their way to make cars heavier than other brands.I meet extreme mass targets all the time, using exotic materials that cost a fortune, but it has to be the objective and time/money spent.
It doesn't help when manufacturers are saving money by equipping cars with everything and then offering subscription services to use stuff that you might never have considered buying. That isn't an engineering decision but a management one.
That weight doesn't actually seem that bad given the bloody size of the things. Hell, my E92 335i weighs I think around 1600kg. The only car I've had which would be a direct comparison (size/body shape) was my Nissan S14a 200SX which I think was around 1200kg and it felt like a tin can in comparison. To 'only' be 400kg more and have a larger engine, sound proofing, an extra turbo, interior quality, tech and better crash protection is quite impressive.
I personally think ICE cars are at a sensible balance just now between weight/safety. I dare say to get an original RS4 to the same safety standard as the current one would end up weighing over 2 tonnes.
I personally think ICE cars are at a sensible balance just now between weight/safety. I dare say to get an original RS4 to the same safety standard as the current one would end up weighing over 2 tonnes.
I reckon the GMA T50 is a guide if money is no object. Say it weighs 1000kg. Was ridiculous and expensive the lengths they went to save weight, there is an interesting youtube video about it. Something like the brake calipers went through dozens of iterations, shaving grams at a time, using computer simulation etc.
A similar ball park car like a McLaren 720s might be 1500kg.
So a huge estate like a RS 6 might be 2/3rds of the weight, 1350kg ish using no expense spared, cutting edge materials and construction?
A similar ball park car like a McLaren 720s might be 1500kg.
So a huge estate like a RS 6 might be 2/3rds of the weight, 1350kg ish using no expense spared, cutting edge materials and construction?
Edited by anonymous-user on Wednesday 19th July 11:28
John_S4x4 said:
They could have made it lighter still by not including that excess apostrophe!
J4CKO said:
John_S4x4 said:
Yes, nice but not sure its a direct competitor for an Audi estate.Not sure its laziness, there is just so much packed in and all the manufacturers are broadly similar weight for the same class of car, all now 4wd in that class as well.
Arent Mclarens typically 1400/1500 kilos ? that a 2wd, carbon tubbed 2 seater, the Audi at 1700 odd doesnt seem that bad given 2 extra driveshafts, three more seats and a big box for carrying stuff.
Part of the issue these days *is* safety etc and no one wants to go back to the tinfoil cars that crumple if you look at them but equally it's the additional power that people demand when then means that they need a stronger, stiffer (heavier) chassis, stronger (heavier) suspension, bigger (heavier) brakes, wider (heavier) wheels, wider (heavier) tyres etc etc.
Not to mention that lightweight is expensive. Cast steel is cheap, uprights, knuckles, hubs and arms etc are easy to make, reliable and long lasting. Light weight versions would add a lot of cost for little relative gain.
You can look at the M-cars as being a good example of this, basically the reason why they are so expensive is they take the cooking model and throw away or modify 99% of it but the top end "cooking" versions are 95% of an M-car. You end up with 2x the cost for a mere 5% improvement.
J4CKO said:
Yes, nice but not sure its a direct competitor for an Audi estate.
Given the RS4 featured in the article earlier today is substantially lighter than the 'new' C63 AMG, shouldn't Audi rather be applauded for managing to still produce an ICE 'performance estate' than made an example of? 
J4CKO said:
Suppose a good example was Jaguar going for Aluminium on some models, for example isnt an XJ typically on par with the smaller XF as it is a steel construction ? possibly lighter.
My mind also went to the last generation XJ, which was 200kg-300kg less than the contemporary S-Class or A8, yet didn't give much (if anything) away in terms of luxury or perceived quality - nor was it marketed at a significantly different price.Scale back a 5.2m V6 barge (weighing 1750kg) to a more sparsely appointed 4-pot, 4.6m compact exec and you might be at ~1400kg.
(Actually a 1.0 steel bodied Mondeo is already 1450kg, so a bit more focus might equal 1300kg.)
John_S4x4 said:
About the same as an Austin 7 and not very surprising given the nature of the thing.vaud said:
The Mark 1 Audi A8 was 1,540kg...
The concern there was that their large-engined offerings would all come with 4wd, and thus a weight disadvantage, so weight saving was a genuine concern. A 12 cylinder A8L of that era is a duffel bag away from being as heavy as an S600L (W220), but the same body with fwd and a V6 is a lot lighter than the equivalent Merc. Aluminium body + smallish engine + fwd - all good stuff.
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