By on December 13, 2008

One of the main improvements in future cars and associated global platforms: weight reduction. Thanks to new, stricter emissions and fuel consumption regulations, this trend is well underway. New cars have already stopped gaining weight. And manufacturers are redoubling their vehicular dieting efforts. Their progress has been predictably rapid. for example, future generations of the European compact class (e.g. Focus III, Golf VII) should shed We more than 100kg, using several strategies…

The increased use of high strength steels allows the use of thinner sheet-metal, although this poses other issues in stiffness, vibration modes and welding processes. The key factor: one can not just replace steel grades. Carmakers must deploy a holistic approach involving changes in manufacturing process. Expect more hydroformed parts and hot stamping of ultra high strength steel grades.

Another, more expensive trend in the body structure: increased use of aluminium and steel in panels and other parts. BMW is committed to this strategy; it already does so in the current 5-series. You can expect an increasingly advanced mix of materials within two car generations. A recent joint-research project of several European manufacturers previews an aggressive mix of different materials (see figure below), although this still poses many challenges in cost and manufacturing robustness.

Of that 100kg expected to fall by the wayside, about a 30kg reduction will come from the body structure. The rest wil be shed from, well, everything else. Car manufacturers are telling their suppliers that new parts must be both cheaper and lighter than the old ones. Careful design and the cost-leverage of global platforms should help git ‘er done, as witnessed by the new Ford Fiesta.

Weight reduction can create a virtuous cycle of further weight reduction. For example, if the overall structure and components are lighter, reduced stress enables a lighter suspension. Light weight opens the possibility of engine downsizing while maintaining performance, or better yet, increasing engine performance with turbocharging…

[Click here for David's auto-future website]

Get the latest TTAC e-Newsletter!

41 Comments on “Auto-Future: Adding Lightness...”


  • avatar
    tced2

    There has been considerable emphasis on engine and transmission improvements to get better efficiency, performance and emissions. Weight reduction is another way to get these goals. I welcome similiar sized vehicles that weight less.

  • avatar
    marshall

    My 1984 Honda CRX weighed less than 1750 lbs (800 kg).

    Are there any modern cars that light?
    Even the SmartCar weighs more than that.

  • avatar
    crackers

    Does this mean that the cars of the future will get blown around like paper airplanes when passing through the wake of a large truck?

  • avatar
    Dr Lemming

    It’s about time — vehicles have really blimped out of late, and it ain’t just because of added safety features.

    The next step would seem to be trimming down the size of vehicles. There’s room virtually across the board for at least modest reductions in length and/or width. Done right such downsizing would have virtually no impact upon the roominess and utility of the vehicle. It would merely cut the fat.

  • avatar
    RGS920

    Lotus vindicated?

  • avatar
    andrichrose

    The Audi A2 from 1999 weighed in at just 845kg
    not bad for a four door, four seater , it also has
    a drag coefficient which still has not been matched
    in any new small car .
    Unfortunately Audi stopped making
    it a couple of years back citing its all aluminium
    construction as too expensive . Driving it you
    really notice the difference , the car is very brisk
    in acceleration despite only having a small 1400cc
    motor , but the biggest difference is its ability
    to maintain speed on hills whilst driving on a
    motorway , it also returns about 15% better mpg
    than the equivalent VW offering with the same
    motor .

  • avatar

    Ever since Newton and Slimfast, we know that losing mass is the secret to saving energy. The challenge is to make cars light and safe. It can be done. A tank is only safe is the other car is lighter. Tank against tank, or tank against wall is an unsafe car. The secret to safety is controlled energy dissipation. The Europeans are ahead in that field. It needs a super computer to do the crash simulations. 1998, VW introduced the Lupo 3L, as in 3 liters per 100km (78mpg.) By using aluminum and magnesium alloys, the weight was brought down to only 830 kg (1830 lb.) That along with its 1.2 litre turbocharge 3-cylinder diesel engine was the secret to the high mileage. But there was a problem: The space-age metal made it too expensive. It didn’t sell. A fuel miser is only attractive if it has the right price.

  • avatar
    63CorvairSpyder

    I can recall several times while at college in the 60s, “pranking” people driving the small imports of the day. Four to six guys could literally pick these cars up(VW Bugs, Sprites, Minis, Triumph Herald, etc); turn them 180 in a parking place, put them on the sidewalk, behind a bush, against a tree and then hide and wait for the unsuspecting owner to return.

  • avatar
    Edward Niedermeyer

    Welcome to TTAC! Enjoyed your blog, there’s a lot of interesting stuff there. This issue of weight is fascinating both from a technical standpoint and as a matter of public policy. As Bertel points out, a car is safe only in relation to the other vehicles on the road. It seems to me that the American market has experienced a kind of vehicular arms race. I’ve thought for some time that basing tax credits on results rather than technology (mpg thresholds instead of “it’s a hybrid”)make sense. Though this would give some incentive to cut weight, more is needed. The weight issue is one point of overlap for enthusiasts and greenies, and it’s good to see the need for reduced vehicle weights being publicized in that context.

  • avatar
    davey49

    crackers expresses the sentiment of many a car buyer
    No matter how much you explain that light cars can be very safe and comfortable a lot of people associate weight with safety and comfort.
    Dr Lemming- I think just selling tiny cars in the US would be a start. I’ve talked to a number of Americans who would be interested in buying an Opel Agila or Corsa, Ford Fiests or Ka, VW Fox or Polo, etc

  • avatar
    Bunter1

    Those concerned about safety may want to go through the IIHS status report on actual death rates of vehicles on the road (latest was April ’07?).
    No test data or opinions, Just a list of vehicles and which ones have more or fewer deaths in accidents.

    While there is some correlation to size one of the interesting things is that many smaller vehicles have better rates than larger ones.
    Final safety seems more dependant on individual vehicle design than the category/size.

    Demographics clearly play a part also, 2 door variants nearly always have a far higher rate than their more mundane counterparts (no prizes for figuring that out).

    I also noted that certain manufacturers tend to have the best scores in most categories and others tend to do poorly across the board. Let’s just say you may be safer in some small and mid-size cars from some companies than you are in some companies monster trucks.

    Worth a look.

    Bunter

  • avatar
    Bunter1

    Crackers- aerodynamic design has a huge effect on wind moving the car.

    Semis weigh a lot, but get blown all over (and sometimes just blown over) because they are billboards.

    Density and profile are the keys.

  • avatar
    sitting@home

    As Bertel points out, a car is safe only in relation to the other vehicles on the road. It seems to me that the American market has experienced a kind of vehicular arms race. I’ve thought for some time that basing tax credits on results rather than technology (mpg thresholds instead of “it’s a hybrid”)make sense.

    How about this for a plan … re-introduce the 55mph highway speed limit for any vehicle that is qualified as a “light truck”. This would kill two birds with one stone; lower fuel consumption and lower the risk of fatal SUV on car collisions, all without the need for new taxes. People couldn’t complain about it limiting freedom, because the choice to drive whatever vehicle they want is still there. It would also discourage manufacturers to circumvent mileage and safety standards by qualifying their cars as light trucks. The testosterone laden monster truck driver, normally tailgating and cutting everyone up on the freeways, would certainly have his ego deflated with each passing Corolla.

  • avatar
    MikeInCanada

    While I am not a big motorcycle enthusiast, I must say how impressed I am at the level of engineering that goes into today’s bikes. The extensive use of aluminum and composite structures have made these machines even lighter and stiffer then previous models. I hope car manufactures take note.

  • avatar

    YAY MORE FUTURE-CAR!!!

    Psyched to see one of my recs in: http://www.thetruthaboutcars.com/time-to-bash-ttac/ worked out for the site.

    Nice blog David!

    ++ Here’s the PBS thing I meant: http://www.pbs.org/wgbh/nova/car/

    You can watch some of it here: http://www.pbs.org/wgbh/nova/car/program.html

    Now bring on the Beryllium valves, Cobalt roof-pillars, Carbon Fiber cupholders…

    -And the Magnesium engine blocks!!! ;D


    BTW. Re: the bashing thread. If for some reason, you feel the need to Hide a graphic for the reasons @Banger,12/12,10:58am: notes, you could do it like this page: http://www.metavitae.com/archives/2007/03/deez_eees_myy_c.php

    The JavaScript for which is:

    <img id=”img1″ name=”img1″ src=”Your Top/Cover Img Src Here” onclick=”javascript: document.img1.src = (document.img1.src == ‘Your Top/Cover Img Src Here’) ? ‘The Img You Want To Temporarily Hide Here’ : ‘Your Top/Cover Img Src Here’;” />

  • avatar
    arapaima

    Someone needs to figure out how to make ceramic engines work. That alone weighs less, plus you get to take out the radiator and other devices that are used to cool the engine.

  • avatar
    JG

    Cool, the manufacturers are coming around.

    Now just add lightness to the current crop of North American drivers so they fit better in these smaller, lighter new cars.

  • avatar
    zenith

    I agree that profile has a lot to do with stability.

    My old 2150 lb. Dodge Rampage was low and sleek compared with my current Ranger @2770lbs. I felt much more secure in crosswinds in the lighter, lower vehicle.

    Trash-talk FWD all you like, but the Rampage didn’t need an ounce of sand in the back to improve winter traction/reduce rear axle hop.

  • avatar
    Pahaska

    I can recall several times while at college in the 60s, “pranking” people driving the small imports of the day. Four to six guys could literally pick these cars up(VW Bugs, Sprites, Minis, Triumph Herald, etc); turn them 180 in a parking place, put them on the sidewalk, behind a bush, against a tree and then hide and wait for the unsuspecting owner to return.

    I remember leaving the officer’s club many times circa 1955 in the wee small hours to find my Nash Metropolitan parked crosswise in front of the door. SOme careful maneuvering let me back it down across the grass.

  • avatar
    Johnster

    63CorvairSpyder : I can recall several times while at college in the 60s, “pranking” people driving the small imports of the day. Four to six guys could literally pick these cars up(VW Bugs, Sprites, Minis, Triumph Herald, etc); turn them 180 in a parking place, put them on the sidewalk, behind a bush, against a tree and then hide and wait for the unsuspecting owner to return.

    They did that when I was in college, too. But it wasn’t for a prank. They would move small imported cars to steal their parking places. Owners of small imports would find their cars on the lawn or on the sidewalk, usually with a parking ticket, or sometimes they wouldn’t find them because they had been towed away after being left on the lawn or the sidewalk. Talk about adding insult to injury.

  • avatar
    jimmy2x

    sitting@home:

    How about this for a plan … re-introduce the 55mph highway speed limit for any vehicle that is qualified as a “light truck”. This would kill two birds with one stone; lower fuel consumption and lower the risk of fatal SUV on car collisions, all without the need for new taxes. People couldn’t complain about it limiting freedom, because the choice to drive whatever vehicle they want is still there. It would also discourage manufacturers to circumvent mileage and safety standards by qualifying their cars as light trucks. The testosterone laden monster truck driver, normally tailgating and cutting everyone up on the freeways, would certainly have his ego deflated with each passing Corolla.

    That would work out real well in 65 and 70 mph speed limit areas. How about you drive what you wanna drive, and I’ll drive what I wanna drive?

  • avatar
    Rev Junkie

    Finally, Colin Chapman, your battle is won! This is the best way to get the fun back in cars. The first car I drove was an ’88 Civic DX stripper, had no power anything, manual steering, not even cupholders, and as a result weighed less than a ton. That thing was great fun, really tossable, and a great connection between man and machine. That car is the reason I love driving, and also why I’m a Honda fan. I can’t wait until this effect spreads across the entire industry! Imagine an ultra-light Miata!

  • avatar
    rpn453

    While I am not a big motorcycle enthusiast, I must say how impressed I am at the level of engineering that goes into today’s bikes. The extensive use of aluminum and composite structures have made these machines even lighter and stiffer then previous models. I hope car manufactures take note.

    More money goes into engineering cars than bikes. The car manufacturers already know that very few people will pay $60,000 for a basic compact car, so they use cheaper materials and manufacturing processes and sell them for the price of a motorcycle instead.

  • avatar
    johnny ro

    Ford made an aluminum taurus, back in 1990s if I remember right, it looked nomral but had aluminum structure. Design experiment with Alcoa. Reviews in popular press said the car was 500 lbs lighter which transformed into far higher performance with same drive train.

    Audi B8 A4 site claims to be 100 kg lighter than predecessor due to high strength steel and other mods. I might be off, maybe its lbs (lazy me).

    Mazda3 next gen is bigger and lighter from what I read.

    So its not “future” its “now”.

    This is wonderful good news, and topic is also a wonderful change from steady drumbeat funeral dirges of late on this site.

    I love bikes too, they are ahead in some areas, behind in others, its a different mission in a different market so it gets a different machine. They have higher performance for sure, 16k redlines with nitrided forged shotpeened rods and titanium valves and so on. X% better every year. They trail in in emissions and also in climate control and on board consumer electronics.

  • avatar
    Dimwit

    Vis a vis the motorcycles: there isn’t much there. Any weight savings are going to come from exotic materials and expensive engineering. Can’t just change the trunk. :) (ya, I know, I should change my handle to Captain Obvious).

    By the same token though, what can happen in dear old DeathWatched plagued America? GM might not have the resources to re engineer their vehicles. Lightness is not cheap, especially if you have to keep up safety standards in the process of reducing mass. All those wonderful cars of yesteryear, praised for their nimble handling attributed to lightweight components, wouldn’t be allowed to be sold by the governments of today.

  • avatar
    Redbarchetta

    Awesome they are finally going to get back to making cars lighter and more compact instead of supersizing every new model. I can’t wait to start giving them my money based on cleverness of design, engineering and packaging prowess rather than who can build a bigger engine on a fatter chassis.

    One of the great consequences of super high gas prices.

  • avatar

    Hi David, I’ve been enjoying your blog for a long time. An excellent survey of what’s going on, and what’s going to happen!

    Weight reduction and energy conservation go hand in hand – with the added benefit of potentially snappier handling and maneuverability.

    Steven Chu, the incoming Energy Secretary, will make energy conservation his prime activity (duh!), but will do so by promoting using engineers and designers, not lobbyists and regulators.

    He sends a Note to Detroit over at the New Yorker: Consider the Refrigerator.
    http://www.newyorker.com/online/blogs/tny/2008/12/note-to-detroit-consider-the-r.html

    Refrigerators consume a lot of energy; all alone, they account for almost fifteen per cent of the average home’s electricity use. In the mid nineteen-seventies, California—the state Chu now lives in—set about establishing the country’s first refrigerator-efficiency standards. Refrigerator manufacturers, of course, fought them. The standards couldn’t be met, they said, at anything like a price consumers could afford. California imposed the standards anyway, and then what happened, as Chu observed, is that “the manufacturers had to assign the job to the engineers, instead of to the lobbyists.” The following decade, standards were imposed for refrigerators nationwide. Since then, the size of the average American refrigerator has increased by more than ten per cent, while the price, in inflation-adjusted dollars, has been cut in half. Meanwhile, energy use has dropped by two-thirds.

    The transition to more efficient fridges, Chu pointed out, has saved the equivalent of all the energy generated in the United States by wind turbines and solar cells. “I cannot impress upon you how important energy efficiency is,” he said.

    We’ll be seeing similar achievements in automotion and mobility.

  • avatar
    Areitu

    Maybe they’ve run out of things to make more efficient within the scope of what they are able and willing to manufacture, and the next best thing to do is to begin decreasing weight. Carbon fiber recycling, as well as efforts to bring the cost of it down, should help greatly in this regard.

    However, use of exotic and high strength materials will also mean that cars are more likely to be difficult to repair and more easily totaled. Less bondo, more epoxy.

  • avatar
    John Horner

    The problem with the relative safety/mass equation is that passenger cars in the US share the road with a whole lot of heavy truck traffic, not to mention massive SUVs and pickup trucks. Common modifications to the SUVs and pickup raise ‘em higher and make ‘em wider … which only adds to the threat they pose to everyone else.

    As an engineer I love the idea of adding lightness. As a driver I’m not ready to hop into a sub 2000 lb. car and get on the road with all of the monsters out there.

  • avatar
    michaelC

    The market incentives to make lighter vehicle should not be confined to energy savings.

    No fault insurance is a subsidy to SUVs and heavy vehicles because they cause more damage in an accident with a lighter vehicle, but the liabilities are divided equally. So people who drive smaller, lighter cars subsidize those who choose SUVs and other heavy vehicles.

    This perverse incentive is especially caustic because of the inclination for people to buy heavy vehicles for their relative ‘safety’ in a crash with a smaller vehicle. Sad to say, many owners of these vehicles consciously adopted this beggar thy neighbor attitude as they fueled the heavy/large/SUV/truck arms race on the highways. Yet another reason thinking people might view drivers of SUVs and light trucks, most of whom can live easily with a smaller vehicle, as egotistical and anti-social.

    There is an easy, fair, market-driven solution to correct this problem. Stop subsidizing heavy vehicles.

    No fault damages in two vehicle collisions should be proportioned by the kinetic energy each vehicle contributed to the accident. (1/2)mv^2 would shift the burden of paying for damages to the heavier vehicle — where it should be.

    This change is win win win. Manufacturers will be encouraged to build lighter, well-engineered vehicles over their entire range as customers take account of the true costs of insuring a vehicle significantly heavier than the other vehicles on the road. The lower insurance rates will compensate for using more expensive materials ….. and everyone will benefit from enhanced safety when accidents occur.

  • avatar
    arapaima

    at michaelC:

    Personally I think it’s a dangerous path to start mixing physicists and insurance. Plus I think that the faster moving vehicle would end up dishing out more kinetic energy.

    Areitu brings up a good point, some of the more exotic stuff will be impossible to repair (like a steel that receives cold work while undergoing an impact, the only way to fix that is to heat treat the material).

  • avatar
    tesla deathwatcher

    If cars do become electric, and regenerative braking becomes more efficient, weight will be less important than aerodynamic drag. You can then have a very efficient car that has not gone on a diet. But it may look more like an airplane than a car — as the Aptera does.

  • avatar
    michaelC

    @arapaima

    (Assuming you are not being ironic…) The physics and math involved is HS level. The proposal is easy to implement — officers already report the velocities involved in accidents. Regulations could specify the curb weight of the vehicles for calculations.

    A light vehicle would have to be moving _much_ faster to equal the KE of a vehicle twice its weight. Of course relative KE is not the only factor to determine damage/safety, but nobody would dispute that more KE implies more damage and a more dangerous collision for the occupants.

  • avatar
    PeteMoran

    @ michaelC

    Here in Australia there is pressure to implement such a scene, but the same researchers recommending it believe they’re seeing it in insurance industry responses already.

    For example; if a Landcruiser is involved with a Civic, there is a higher chance that more damage will be done to the Civic and occupants. The Landcruiser insurance payout is higher both medically and in other party repair.

    Unfortunately, we’re only seeing this reflected as small % increases on insurance so far. I believe however that insurance companies are now very seriously looking at their data for comparative collisions.

    Are SUVs/Trucks not expensive to insure in the USA? I thought they were?

  • avatar
    mxhi5

    Colin Chapman is MY hero.

  • avatar
    davey49

    PeteMoran- no more than any other car and very often less

  • avatar
    PeteMoran

    When I was there a few years ago, a Wyoming friend of mine showed me his new F150. He said “it would probably get better mileage if there wasn’t all that safety stuff weighing it down”.

    Errr …. it wouldn’t have anything to do with it being big anyway would it? He didn’t need it, but everyone had one!

    Apologies to Wyoming residents, you’re wonderful people.

  • avatar
    KeithBates

    @PeteMoran

    I had a ’57 F100 that could get 19mpg, my ’86 with the same sized
    engine can get at best 16mpg. The ’57 is heavier…
    Explain that…

    SteveL

  • avatar
    PeteMoran

    @ KeithBates

    I’ll give it a shot.

    Maybe because the Y-Block V8 was only “rung” out to 186hp rather than 300hp +. More power is more fuel even though technology is leaps ahead.

    Now if they stuffed a high-tech 186hp V8 into the latest F150….. Hang on, those wouldn’t sell.

    Just for fun, the Model T got 28mpg, a Formula 1 car gets 3mpg. A 27L Rolls Royce Merlin V12 in a car would get 0.1mpg.

    http://web.telia.com/~u13203489/ItsAlive3.MPG

  • avatar
    Richard Chen

    About that BMW 5-series front end: the tradeoff is that’s it’s a costly PITA to repair.

  • avatar
    guyincognito

    Amen! One often overlooked source of weight in modern vehicles is sound deadening. Maybe we can learn to live with a little more NVH?


Back to TopLeave a Reply

You must be logged in to post a comment.

Subscribe without commenting

Recent Comments

New Car Research

Get a Free Dealer Quote

Staff

  • Authors

  • Brendan McAleer, Canada
  • Marcelo De Vasconcellos, Brazil
  • Matthias Gasnier, Australia
  • J & J Sutherland, Canada
  • Tycho de Feyter, China
  • W. Christian 'Mental' Ward, Abu Dhabi
  • Mark Stevenson, Canada
  • Faisal Ali Khan, India