Last post on Sep 05, 2008 at 8:44 AM
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Fuel Efficiency (MPG), Automotive News, Future Vehicle
#33 of 52 Re: and yet [andre1969]
Sep 02, 2008 (7:38 pm)
Sure, highway mileage is all about momentum. Once you have the thing cruising at 70, it only takes a very small percentage of the engine's power to keep it at that speed. OTOH, lugging all that weight away from stops drags the fuel economy down.
#34 of 52 Re: and yet [nippononly]
Sep 02, 2008 (7:44 pm)
Are vehicles too heavy? Yes. Surprisingly, my favorite example of weight control is that ugly American, the Corvette. They weigh no more today than they did 20 years ago! Contrast that to any other car, domestic or imported. The major culprits in weight gain? As mentioned, it's a combination of size, power, handling, comfort, and safety. How many car reviews have you read that said "the new Whatever is 50/80/120% stiffer than the old model"? And how many ads trumpet 5-star crash performance? So don't kid yourself, to get lighter cars will require us to sacrifice some combination of size, power, handling, safety, comfort, and money. Car designers aren't stupid, they don't have blocks of iron hanging off that can just be deleted.
#35 of 52 Re: and yet [texases]
Sep 03, 2008 (5:43 am)
I am a big Porsche fan, but it is embarrasing to me how much better Vettes have done with weight than 911s over the past 30 years. Off the top of my head, I can't think of another car that has lost weight over that time period. Similar engine, similar size, a lot more space inside on the new one, and all the safety stuff has been added. How did they do it?
#36 of 52 Re: and yet [lemmer]
Sep 03, 2008 (6:48 am)
The real trick for automakers will be getting weight under control in models that DON'T cost $50K, and seat more than two.
It is a shame that no-one ever touts the advantages of lower weight in marketing. If they did, we might have people clamoring for lighter cars, giving automakers financial incentive to do something about the pork.
#37 of 52 Re: and yet [lemmer]
Sep 03, 2008 (7:06 am)
"How did they do it? "
Well, you could say that they had lots of room to improve, what with the earlier Vette's heavy frame, etc. They really went after improving the chassis through better design, rather than more metal. Don't they use some kind of balsa composite in the floor for stiffness? And aren't the springs now fiberglass?
#38 of 52 Re: and yet [texases]
Sep 03, 2008 (7:24 am)
I'd imagine they've also seen some weight savings in the engine block, itself. Now I don't know how advanced the Corvette's engine was 20 years ago, but the Chevy smallblock was always a pretty chunky little engine. Low reciprocating mass and small size yes, but in overall weight it was a bit of a porker.
Still, I'm sure just about everybody has saved weight in their engines compared to 20 years ago yet the cars themselves are often heavier, so evidently the Corvette has been toning down the excess in other areas, as well.
#39 of 52 Re: and yet [andre1969]
Sep 03, 2008 (7:59 am)
"I'd imagine they've also seen some weight savings in the engine block, itself."
I think you're right, what with the current aluminum block, heads, etc. Another weight-saver (well, weight gain avoider) is the continued use of the OHV design. Gotta be saving a lot of weight compared to having 4 OHCs, had they gone that route.
#40 of 52 Re: and yet [nippononly]
Sep 03, 2008 (12:22 pm)
Maybe we should look at "weight per passenger". A 5000 lb vehicle that can carry 8 would have a 625 lb per passenger number. A 3000 lb vehicle that can only carry 4 would have a 750 lb per passenger number.
#41 of 52 Re: and yet [ronsmith38]
Sep 03, 2008 (7:17 pm)
Nah. The problem with that approach is that whether it is a vehicle designed for 4 or 8, it will most often be carrying 1, or 2 at the most. Americans overbuy when it comes to their vehicles.
And either way, as Lovins points out, the percentage of a car's curb weight that it can carry as passengers and cargo is much too low.
#42 of 52 Re: and yet [nippononly]
Sep 04, 2008 (5:43 am)
In one of my cars, I like some reserve capacity just for convenience. I have a family of four, but sometimes I throw in a couple of grandparents or somebody else's kids. On the other hand, the car I drive barely has room for the four of us. I think We all overbuy because the incremental cost of doing so has historically been so low.