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Old 04-16-2020, 05:39 PM   #5 (permalink)
Aero Wannabe
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Join Date: Dec 2007
Location: NW Colo
Posts: 718

TDi - '04 VW Golf
90 day: 50.21 mpg (US)
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DWL Driving With Load

Some Ecomodders get good results with a gas/petrol engine by Driving With Load. You can use LOD on the Scanguage to monitor engine load and try to lock your foot in one position and drive with a constant load on the engine. This is sort of the opposite of what most cruise controls do. The factory cruise control will accelerate wildly uphill and at the crest go into engine braking. (Older gasoline engines do not have DFCO) This wastes fuel on the way up and kills your momentum, wasting fuel on the way down. In hills the use of cruise control is not the most efficient way to drive. DWL allows the driver to hypermile by anticipating the road ahead and allowing the car to slow somewhat on the way up and speed up (or E-On C) on the way down. In my experience with the TDI I have not seen significant mpg gains using DWL. The turbodiesel has tons of torque so even in a 1.9 4 cylinder most hills can be summited without a downshift. That said, it makes sense to use a modified version of this technique. If there are no other cars, I may slow slightly on the uphills if I anticipate that I will gain too much speed on the downhill. On rolling gentle hills I prefer to crest the hill at or slightly above the speed limit to extend my glide phase for as long as possible. This gives me better trip average mpg in my experience, and allows me to stay closer to the speed of other vehicles on the road. Here in the West the posted speed limit is 65 mph on rural highways but most of the traffic is driving 70 mph or higher.
60 mpg hwy highest, 50+mpg lifetime
TDi=fast frugal fun

Originally Posted by freebeard View Post
The power needed to push an object through a fluid increases as the cube of the velocity. Mechanical friction increases as the square, so increasing speed requires progressively more power.
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