On 19/04/2007, at 7:01 AM, Dan Minette wrote: > > Here, AWD means all wheel drive....
Yes, that's what it means everywhere. There are transmission losses. These are greater in an AWD car, obviously. It's why power ratings are given at the flywheel for tuning, but at the wheels by manufacturers. > but I know I have much more than a > catalytic converter on my car. Googling the details is harder than I > expect, so I don't have the exact details. But, I know that my > anti-pollution system does take power, via a belt connection to the > engine. > My recall is that this is a significant power drain and involves the > recycling of exhaust gas. Possibly, there are various systems. It's a couple of percent power loss. It's irrelevant to the point - cars are more efficient, they're doing far more with the same fuel than they used to. > One thing that strongly influences my memory was my ownership of a > car that > _actually_ got 50 mpg on the highway (or at least 48) and about 40 > in town. > It was a 1979 VW Diesel Rabbit, and seated 4. Diesels were not > subject to > restrictions at that time, but gas powered autos were. The > comparable gas > Rabbit got ~30 mpg//25 mpg. We don't see widespread us of this option > now...certainly less than in the late '70s. I recall reading that > this was > due to the difficulty of both having the pollution control equipment > required in the US and the superior mileage. Comparing diesel to petrol is apples to pears, and you know that. Of course the petrol car did worse than the diesel, petrol cars always do. Diesel cars these days get astonishing consumption figures, even better than they used to. Our next car is likely to be a Madza 6 Diesel estate, which has a 2.0 litre turbo-diesel and combined figures of 38mpg (so will do better than that at cruising speed on the open road), yet is bigger and heavier than your 1979 VW, and has all the pollution control and mod-cons you'd expect in a modern car, while having performance figures like a petrol car. For the same fuel type, cars are doing far more with the same amount of fuel. When taken to extremes, like some of the little Japanese runabouts with 3-cylinder 850cc turbo petrol engines, or the Smart, they can get 80mpg on the open road at 60mph. Charlie _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
