I'm thinking maybe a molding strip shaped in an appropriate cross section. What is sometimes called a bullnose. Shaped like a "D" but the rounded part extending out further. Usually milled wood but now also made of synthetic.
Attach to rear face of car's sheet metal. Flat part attached to car body; rounded "fin" extending rearward. This can be across the top edge, and also vertical strips on the two rear sides.
Currently getting +/- 50 mpg in fall weather. EPA is 31/39 so not too shabby. WAI, fuel cutoff switch, full belly pan, smooth wheel covers.
My fluids professor showed what the most aerodynamic car could look like. The tail was as long as the car and smoothed out the air stream. The front kind of had an egg shape and off course it had wheel well skirts. It pretty much look like that cars that have mph records on the salt flats. If anyone hasn't looked at these cars you should.
Speaking of salt flats, has anyone else seen The Worlds Fastest Indian? Great Movie!
Paul definitely knows a thing or two about aero. I'm a newb at it, but I'm doing my best to catch up.
I was watching a show about sports balls and their evolution throughout history (History channel?) and they spoke of how the discovery of the dimpled surface being aerodynamically better after golfers noticed their old, nicked up balls traveling further.
I see no reason why fuel economy and power cannot coexist.
Think my windshield wipers are really worth the full 7.1% ? I almost hope so. I've been dying to get a coroplast cover that mounts at the hood hinges and rides just upto the height of the wipers. Anyone had luck w/this? I'd rather not remove the wipers.
I tried taking the wipers off of Stinkerbutt for a series of highway runs a couple of weeks ago and got nothing. From what I can tell from my past several vehicles (both truck and auto) when the wipers are running in the rain they don't start to "skip" on the windshield until over 80 mph or so, so they probably don't cause too much drag when parked at the rear of the hood. My thought is that since the aero impact doesn't cause the wiper assembly to rise off the glass until higher speeds, there probably isn't any interference from the assembly in a parked position at normal speeds.
That said, a Ford F-150 (old style) with a flat front end has a bigger problem at 75 mph or so with the wipers. A Kia Optima doesn't as does a Dodge Dakota or a Ford Windstar. The three latter have a more aero friendly front end.
Since the book was written in the 70s', well vehicles weren't nearly as aero friendly back then. It would be interesting to do a tuft test at some point using several vehicles with the tufts on the wipers.
Proud owner of Stinkerbutt!
-Air Raid cone filter, direct to TB
-Homebrew front air dam
-Homebrew side skirt
-Torza top bed cover
-Now featuring front wheel canards!