We can talk about sophisticated turbocharged and direct-injected engines all we like, but the reality is that ballooning vehicle curb weights are going to have to come down as fuel economy standards go up. Just how hard is it to get significant amounts of weight out of everyday midsize vehicles? Lotus Engineering has taken a stab at answering this question using a Toyota Venza as the subject vehicle.
The Venza is part of 300-page tome of a report released by Lotus today. We've attached it here if you want to skim it (and really, it's written in a way that you don't have to be an engineer to do so). Lotus took a look at the baseline weight distribution of a 2009 Venza and looked for ways to cut weight without compromising ride and handling dynamics, safety or NVH control. Keeping costs under control was also a priority.
The company came up with both a nearer-term target of 20 percent weight reduction with a feasible production date of model-year-2017 and a longer-term target of a 40-50 percent weight cut with production starting in model-year-2020. Ultimately, Lotus says it was able to trim 21 percent and 38 percent for the respective targets.
The nearer-term target would significantly reduce the use of medium-strength steel and iron (which today account for 52% of materials use in the Venza) and swap in lighter, high-strength steel. In the longer-term, Lotus envisions the Venza using equal parts high-strength steel, aluminum, cast magnesium and plastic (and only 7% ordinary steel/iron).
The recommendations are based on the assumption that lightweight materials regarded as exotic today will eventually come down in price. Lotus points out that even today the modestly priced 2011 Ford Mustang has an aluminum hood, while the Lincoln MKT uses magnesium castings for its liftgate.
Indeed, for the nearer-term Venza concept (2017 model year), the company thinks it would actually be possible to reduce development costs (not including the powertrain) by 2 percent. For the 2020 model, Lotus anticipates costs would rise by about 3 percent.
vvk says:
11:38 AM, 04/27/10
Subarus have had aluminum hoods for years.
As far as making Venza lighter, I think Lotus is just wasting their breath. Vast majority of Venza buyers want their car to be as heavy as possible. They equate vehicle weight with safety.
throwback says:
11:44 AM, 04/27/10
Not surprised they found ways to cut weight. My question is at what cost? Lotus is assuming these exotic (for cars anyway) materials will come down in price. I think that is a heck of an assumption.
xprojected says:
12:37 PM, 04/27/10
"Simplicate and add lightness" is a well-known saying among engineers. Google it or the man it's credited to, William Bushnell Stout.
subytrojan says:
12:42 PM, 04/27/10
Neat blog entry.
vvk, the Impreza lost its aluminum hood with the third generation redesign. :(
atenza94546 says:
01:16 PM, 04/27/10
Reduce weight and add a couple more of the over size cup holders !!!
What about the junks people keep in their trunks ???
Maybe just start reducing the over all car size !!!
clarkma5 says:
04:45 PM, 04/27/10
THIS is what I'm waiting for with much excitement from the future of cars!
I mean, think about what amazing stuff we could be seeing...cars for the last ten years have been getting bigger, heavier, faster, and cleaner. Now imagine if we could apply the powertrain technologies and engine efficiencies that make a 300+ HP large displacement V6 sedan get the same or better mileage than its decade-old, 200 HP forebear and apply those to a lighter car...a lighter car meaning you need less engine and less power. Suddenly we can start to see what happens when you compare a 200 HP 3000 pound sedan from 2015 to a 200 HP 3000 pound sedan from 2000 and I think we're going to see fuel efficiency gains on the order of 50%, instead of all those gains being gobbled up by the need for more power to push around more weight (and of course, let's not forget, that more power means bigger and beefier engines and drivetrain components, which means more power, which means more weight, and on and on and on...)
cr_driver says:
09:39 PM, 04/27/10
Take the 2010 cx-9 AWD vrs the mazda 6 V6.
4550lbs, u reduce weight 21% and u got the weight of the 2010 mazda V6!
15/21 mpg of the cx-9, and the mazda 6 delivers 13% better city and 19% better hwy fuel economy with the same engine but weighing 21% percent less.
A 2010 example of what losing weight can do to the fuel economy.
Without taking into account many other variables that affect fuel economy.
isaacl says:
06:27 AM, 04/28/10
This is by far the most interesting straightline post I have read this year. This is a VERY interesting piece. The meat of this matter is whether the American consumer will pay more for lighter vehicles. I am sure that it costs quite a bit more to approach a vehicle design with lowest possible weight as a top level priority. That said, will Aunt Grace mind the price bump for her next Taurus or Camry or RAV4 if all it promised was a 10% reduction in weight? I'd like to think so. I just might skim that report. I'll try to make the time. ha!
agnh says:
03:11 PM, 04/28/10
Any reasonably intelligent person, especially car people, can easily understand and appreciate the benefits of using lighter(but still strong) materials such as magnesium, aluminum, etc. Personally I would love to see the latest crop of 4500lb BMWs, Mercs, etc, go on a 15% diet.
That being said, VVK is right, you cannot underestimate the naivity and stubborness of the average American consumer. Heavy=safe, right?. Let a salesman try telling Mrs. Middle-America that this new 2015 Humphalump Dumpaloon she is looking at will get 10% better fuel economy, even handle crisper and stop better, but weighs 300lbs less with a smaller engine and smaller brakes than before. Good luck.
platf1 says:
07:40 PM, 05/ 1/10
Someone unleash them on BMW...they're gaining weight like crazy.