Fuel Economy at high speeds measured [ Archive] - GasSavers.org - Helping You Save at the Pump


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The Toecutter
05-26-2006, 11:26 PM
http://www.greencarcongress.com/2006/05/fuel_consumptio.html

Amazing. Going 150 mph will drop fuel economy of a diesel to about 10 mpg, when you might normally get 35 mpg at 60 mph in that same car. Gas cars are no doubt going to be worse.

It might be a fair estimate that a gas car that normally gets 25 mpg at 60 mph might only get 7 mpg at 150 mph.

The above hypothetical car with a 15 gallon tank would have a 375 mile range at 60 mph, and a 105 mile range at 150 mph.

In contrast, if an electric car were made that could go 150 mph, it might get 250 miles range at 60 mph with a 60 kWh Li Ion battery pack, and might only get 30 miles range at 150 mph.

A typical gas powered car will have an engine about 10-12% efficient in normal use, rising to 25% efficient if its maximum load is used. This is why vehicle efficiency and range don't drop as sharply as a similar electric car as speed increases. Even still, an EV would be much more efficient overall, with an electric motor still being 60-70% efficient at full load, while in normal use it might be 80-95% efficient.

philmcneal
05-27-2006, 03:46 AM
http://www.greencarcongress.com/2006/05/fuel_consumptio.html

Amazing. Going 150 mph will drop fuel economy of a diesel to about 10 mpg, when you might normally get 35 mpg at 60 mph in that same car. Gas cars are no doubt going to be worse.

It might be a fair estimate that a gas car that normally gets 25 mpg at 60 mph might only get 7 mpg at 150 mph.

The above hypothetical car with a 15 gallon tank would have a 375 mile range at 60 mph, and a 105 mile range at 150 mph.

In contrast, if an electric car were made that could go 150 mph, it might get 250 miles range at 60 mph with a 60 kWh Li Ion battery pack, and might only get 30 miles range at 150 mph.

A typical gas powered car will have an engine about 10-12% efficient in normal use, rising to 25% efficient if its maximum load is used. This is why vehicle efficiency and range don't drop as sharply as a similar electric car as speed increases. Even still, an EV would be much more efficient overall, with an electric motor still being 60-70% efficient at full load, while in normal use it might be 80-95% efficient.

yeah i was thinking about this today at work and was tempted to blow the cash on a used toyota prius I since its the closet thing to an EV i can get without getting under the hood.

mikefxu
05-28-2006, 10:55 PM
I did a MPG at certain MPH test on my GF 2002 Suzuki Aero at 55 got about 40ish at 65-70 got 35ish and at 100MPH it got 25MPG. I set the cruise control at 100 and thought that was pretty good mileage at the speed. Just got the scan guauge and that thing is awesome. My GF keeps yelling at me cause I keep hitting the buttons on the scanguage.

Ryland
05-29-2006, 10:40 PM
are you making your speed/mileage for diesel comparisons off the mercedes? because of you look at the gulf, the two gulfs they tested should show you that the gas was running parilel lower mileage to the diesel, that it droped the same amount for the same shape car at the same speeds, and that arodinamics plays a big part, mercedes are long and sleek with a big engine that is not going to be luged as much as it goes faster, and I think that is part of why people think that going faster doesn't kill their mileage, that a few people tried it in cars like cadilacs (don't some of them have real time mpg gauges?) and saw little change, so it must be true for everything, right?