Wednesday, March 19, 2008

BMW Diesel Beats Toyota Hybrid in MPG Test

Is this a case of man bites dog? A mid-size BMW sedan equipped with a diesel engine returned better fuel economy on a 545-mile, London-to-Geneva, run than a gasoline-powered Toyota Prius. A BMW 520d with a 2.0-liter diesel engine and regenerative braking (but no heavy duty hybrid features) got 41.9 mpg while the full-hybrid Prius, 500 pounds lighter, got 40.1 mpg.

Read more

In the comments section, one Prius owner whimpered that the test was unfair, saying:
"40 mpg for the prius? I have never been able to acheive (sic) any thing less than 50 mpg. This test in (sic) unscientific at best, you have two different drivers whose driving habits can be vastly different. On my prius, I average 55 mpg while my wife averages 48 mpg."

While you're thinking about that, note this line in the main article: "Testers found the (BMW) 520d "not startlingly quick ... [but] it cruised happily at the French autoroute limit (dry conditions) of 78mph towards the champagne region."

And this one: ...To find out, they drove BMW's midsize 5 Series sedan and the Prius London-to-Geneva, adding 100 miles to the route "to give the Prius the advantage of running in urban conditions where its petrol-electric drivetrain comes into its own."

And this one: The Prius weighed 573 pounds less and had an aerodynamic shape "as slippery as a campaign manager discussing political donations," leading the testers to believe "the Prius should take less energy than the BMW to maintain a constant cruising speed." Not so. As many people know, the advantage of hybrids lies in urban driving where the stop-and-go recaptures the car's energy. On the highway, it's one more four-cylinder car pushing through the wind.

So basically, according to this Prius owner, it was "unfair" despite the fact that the driver of the BMW drove it like a BMW, cruising at 78 mph, because the driver of the Prius didn't drive at bicycling speeds and only in city conditions, like a Prius owner with something to prove. It was "unfair" because all the odds weren't stacked in favor of the hybrid.

Not mentioned is the fact that for 30 years VW has been building diesel cars that beat the hybrids at their own game, and there are many early versions of those still out there running around, despite being 30 years old and having a half-million or more miles on them.
Let me clarify that a little more. A 1978 VW diesel Rabbit will get better than 50 mpg if you drive it like you're trying to kill it. It will get over 60 mpg if you take some pains to maximize fuel mileage. I'm not talking about hypermiling; there's no telling what it will do hypermiling. A Prius will get maybe as much as 60 mpg, hypermiling. And I can just about guarantee there will never be any such thing as a 30-year-old Prius, unless it has been in storage all those years.

Now, let me reiterate what I have said in the past: I am not against hybrids per se. In fact, I think most if not all new vehicles will incorporate some hybrid-vehicle technology in the future; witness the regenerative braking on the BMW in this article.
But I AM against the BS political posturing of those who drive hybrids as a form of activism, with their "holier-than-thou" attitude.

If anyone wants to take me up on it, I can build (on an existing, older car like a Geo Metro) a car that will go at least 50 mph, with a fuel mileage of at least 110 mpg (US) and a cruising range of at least 300 miles, for half the price of a new Prius.


Anonymous said...

Several years ago I read an article about a class project that build a car that got 100mpg. I think it was a MGB with a 3 Cyl Kubota diesel engine, 5 speed transmission, and a 2 speed overdrive. This might have been a decade or more ago. In the sixties I read an article in Mechanix Illustrated ( or a similar mag) about how Texaco modified a 50 Plymouth 6 cyl by changing it from a flat head 6 to an overhead valve 6 with fuel injection. By just changing the head it got 50mpg and would run on almost any flammable liquid from gas to peanut oil.

Tracy said...

That's the kind of stuff I like to hear about. I read an article about a Geo Metro that had a single cylinder, 10 hp diesel engine, and it would do 55 mph with 2 people aboard, while getting 110 mpg. The way it was done, though, had some inefficiencies in the name of simplicity; and I think I could improve on it.