how to help my matrix part 2 (front end)

[basjoos]

I've done a lot of driving in the NC mountains which gets a fair amount of snow in the winter. I've never had any problem with snow buildup in the front skirts since the hot radiator exhaust blowing out through the front wheel wells melts any snow that gets up there.

[Weather Spotter]

Basjoos, what was the gain for you from the wheel skirts?
Metro MPG testing showed a small loss, so I am unsure what to do.

[sheepdog 44]

Basjoos, would having the leading edge of the wheel skirt recessed into the wheel well work (or be better) while still having the trailing edge flush with the outside of the car? I think of it like the scales of a fish where the front opening of the wheel well kicks up a fraction of an inch over the skirt, which does the same for the edge of the car. Or is having both sides of the wheel skirt flush with the outside of the car important.

From what i gather across several topics here, doing the best to minimize air going into the wheel well is important. Like on the Probe V series of concepts they have very good deflectors in front of the wheel. I would say minimizing the opening of the wheel well from beneath, and maybe even minimzing the volume of the wheel well would help. One car has an air vent behind the wheel well to vent pressure build up.

For Metro MPG's problem i think cutting off the back couple inches of the skirt would vent pressure while still improving airflow significantly over stock. You can always go with a fixed front skirt that just minimizes surface area of the outer wheel well to the tire itself. If you watch a second gen prius on a rainy day they kick up very little mist cause the wheel well isn't that much larger than the tire. If you watch a car with a big gap they're spraying mist from wells everywhere.

Does lawn edging running the length of the car help with it? Like extending the side of the car nearly to the ground with lawn edging?

[basjoos]

I wouldn't recess the leading edge of the wheel skirt since that would create a small pocket of turbulence behind the leading edge of the wheel well and a recessed skirt would be harder to deploy without rubbing the well (if top hinged) when opening for sharp turns. My front skirts aren't flush with the outside of the car, they bulge out about 2.5" to provide space for the conveyer rollers inside the skirts. The front wheel skirts have a small slit at their trailing edge that vents pressure build up and radiator exhaust air from the wheel well.

My car has a double side skirt (made of coroplast, not lawn edging) running between the front and rear wheels. The distance between the inner and outer side skirt is the width of the tire.

[Weather Spotter]

some data:
last tank 712 miles at 57.7 MPG so I think the nose cone helped 1-2 MPG is my thought so far. more at faster speeds then slow.

[aerohead]

You'll want to start scanning the skies for OPEC fighter jets! 'kidding!

[Weather Spotter]

I want to try for 60 MPG this tank

[HydroJim]

Slap some front wheel skirts on there and you'll get 60 mpg no problem

[Tango Charlie]

Them's some nice numbers there, mister.

[Weather Spotter]

90m miles on new tank, 59.2 MPG so far