Wheel Skirts for better fuel economy
Wheel skirts have been a way that auto manufactures had used to improve on performance for years. They look neat and may get you more fuel mileage. The wheel openings are huge on my Fleetwood Flair RV. I thought of a way to put some on and it did take me two days of work. Great the results but and they look neat.
Total cost was under $20.00 If it saves me 1/2 mile per gallon it would be good money and time spent. I had the 2" X 2" boards on hand so I saved some money there. The hardboard was only $8.79 at Lowe's
The first thing is to consider if the front wheels can be covered. My wheels are 6 inches deep inside from the wheel fenders so that wasn't a problem here. I got some large pieces of cardboard. It was tricky to hold the cardboard up to the wheel wells and draw the shape for the covers. If you can take off a front and a rear cover off then it is easy to draw the shape. Lay the cardboard down on the floor and put the wheel fender over the cardboard. Take a marker pen and trace the shape. Be sure that the wheel well front is facing down to eliminate any angle in the wheel well. Do the same for the other wheel well. Write down the front and rear covers direction they go. It is easy to mix them up.
If you can't take the wheel fenders off. make sure that there is sufficient clearance to put a bolt or a nut and washer through the board and wheel fender. You have to bolt things on securely. I put the bolt and fender washer from the inside of the wheel well and tightened the nuts onto the boards. On the front I had to reverse the direction, I put the bolts through the boards into the wheel well and put the fender washer and nut on the inside. Fender washers have a very large outside diameter and a 1/4 inch center hole. I found my washers at Menards. You need fender washers on the plastic wheel fenders so they won't tear up the wheel fenders.
An unpainted wheel cover
Cover mount boards
The 2" X 2" boards are 15 inches long. Two bolts can be seen on the ends.
The green things are foliage on the other side of the motor home.
I trimmed some wood off the top edges to allow for the curvature of the wheel fenders.
I made one board first as a pattern. It is a15" long 2"X2"
board. I tapered one edge on each end with my chop saw. You will need 12 boards.
I drilled 1/4 inch bolt holes 3 inches from the ends, centered on the 1 inch centerline, the middle of the board.
I made the first one with a Skill saw, but I quickly found that a chop saw would work better. It is safer too.
To make the taper, just hold the board on it's side and bring
the saw blade down to the wood. Then cut the taper. Turn the board around for
the other taper.
It helped to draw a line to follow.
A drill press works really well to drill the holes. Great precision isn't needed, just make 'em look good. You can use a hand drill too.
I used a small piece of hard board to set the depth of the
mounting boards. The C clamp can be seen here holding up the board.
I predrilled the boards so I only had to drill the fenders. Drill them right on the RV. That is the easy part since they are plastic.
The wheel fenders with the 15 " boards bolted on.
The covers fastened on. This how it looks before painting.
The inside view of the cover showing the stiffener board across the bottom.
I put the skirts on front and rear and painted them Ivory to match.
I first traced out the wheel fenders with cardboard and cut them out. I had to trim them for a better fit. I used a 4 ft by 8 ft 1/8th inch thick hardboard for the covers. Paint them with any color exterior paint. I finish painted mine with Krylon Ivory to match. If you can remove the wheel fenders it would make it easier trace and fit the wheel covers.
I found that when I removed my fenders the lower corners of the side walls were water damaged. The metal was totally rusted out for several inches. I wood screwed small 2"X2" boards to fill the missing material. This allowed me to screw the fenders back on. I replaced many badly rusted fender screws as well. I had to remove the back fenders to mount the 15" 2"X2" boards I used. There was a pinch point on one side that wouldn't allow me to put the bolts on. Once I had all three boards mounted I drywall screwed the wheel covers to the 2"X2" boards with 2 inch drywall screws.
I found out that the mounting of the boards on the wheel fenders went much better when I clamped the 2"X2" boards and then drilled the 1/4 inch bolt holes.
Having the covers screwed on allows easy access to the tires if you need to service them.
1 4X8' hardboard.
3 2X2" 8 ft long boards. Cut the boards 15 inches long, 12 required. I ripped 1 of the boards the long way for 1" X 2" boards for the bottom stiffener boards. Measure cover to fit .
28 2" drywall screws for the covers. Seven on each cover. 28 !/4 inch fender washers. Menards had large bags of them available.
20 3/4 inch drywall screws for the stiffener boards. Five for each cover.
Exterior paint to protect the hardboard.
Krylon Ivory spray paint (or your color to match) to finish the covers.
Once all the boards are mounted you can screw the covers on. I
used five 2 inch drywall screws on each cover to the mount boards. You
might want more screws (7).
I noticed that the bottom of the covers would shake if I tapped on the covers so I made 1" X 2" boards that went across the bottom of the covers.
I screwed them on the covers with the stiffener boards on the inside of the cover.