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Old 08-10-2008, 03:34 PM   #7 (permalink)
Bearleener
Efficiency freak
 
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Join Date: Mar 2008
Location: Berlin, Germany
Posts: 58

Frugolf - '96 VW Golf wagon
90 day: 40.36 mpg (US)
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Definitely driving style tweaks will help the most.

Don't underestimate the effect of aerodynamics at low speeds. When I put on my above-bumper grill block I immediately noticed subjectively longer glide times at in-town speeds (60 km/h = 36 mph), whereas at highway speeds the drag effect was actually less noticeable (except that the car feels a lot more stable, less nervous). Even at very low speeds (25 km/h = 15 mph) something's happening because raindrops dripping off the front lip of the hood get blown back toward the windshield, that didn't happen before the grill block. A rule of thumb says that above 60-80 km/h (36 - 48 mph), depending on the car, aerodynamic drag becomes larger than other drag, but that means that below that it's still up to 50% of total drag.

And raising the tire pressure helps, too.
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