Experiment: smooth wheel discs tested A-B-A - 4.6% mpg improvement @ 65 mph

[Otto]

Anybody have the exact outside diameter measurement of such coupe pizza pans?

I'm looking for some that just barely fit inside the bead rim of aluminum wheels, such that the rim supports the pizza pan mounting.

Failing that, may get pizza pans slightly over-sized, and machine their edges down to fit inside the wheel rims.

[Weather Spotter]

the 16" I got are exactly 16". I just did a new set on my winter tires. I got aluminum rims and drilled and taped all 5 spokes of each rim.

[radioranger]

Only tried it on one side and the darn truck kept looping around on me!! next paycheck buying two more pizza's or i could use cardboard ones after i eat the pizza during the superbowl . seriously nice work , one trouble the pizza tins are steel and rust pretty easily plastic might be better, how about some of that fiberglass sheeting stuff they use in bathroom paneling ,

[radioranger]

got another idea, that is so crazy it might be a good one, Since all cars are set up to run straight on a normal highway there is always a tendency to pull towards the shoulder a bit, especially with wear on the parts involved, so the idea, vary the tire pressure a bit say three or four more pounds on the side it's pulling toward, to balance the load on the steering and eliminate the pulll that the power steering pump has to power and use horsepower to fight . any thoughts

[Ladogaboy]

Originally Posted by radioranger

one trouble the pizza tins are steel and rust pretty easily plastic might be better, how about some of that fiberglass sheeting stuff they use in bathroom paneling ,

That's why you get aluminum.

[Wonderjava]

well im very interested in putting moon disks on my car, but im a dork with a wrench and screwdriver...if there is anyone in the omaha or lincoln nebraska area, that is willing to help me with that, i would greatly appreciate it.

WJ

[ECONORAM]

Originally Posted by Thalass

Out of curiosity: Has anyone made transparent wheel covers? That way you'd get to still have nice looking wheels while improving your CoD.

I did--still testing--if I can keep them on the truck. First clear attempt was with 0.100" LEXAN disks. However, I cut them a little too small in diameter...and they moved enough to cause a balance vibration. I used parachute cord to tie them to the wheel spokes because I didn't want to drill holes in the wheel, and the wheels have so much dish I'd need nearly a six inch bolt to hold them from the center. Yep, they started getting scratched up on the edges from all the movement. So did my wheels.

Second clear attempt was with 0.015" LEXAN. This was thin enough to cut with scissors--very convenient. Also thin enough to be rolled up in a box for shipment! Used twine to tie the disks to my wheel spokes. The twine was synthetic and too slick and the knots slipped and the front two covers went flying off. They're somewhere between here and Fort Worth. I also tried nylon zip-ties, but I'm hesitant to continue that as I expect them to wear through the wheel paint.
I've thought about epoxying plastic nuts to the spokes, and using plastic bolts to hold the covers on...or maybe velcro straps that wrap around and through the disk.

I previously tried black corroplast disks with adhesive backed velcro (front ones go flying away), double-sided tape (more fly-aways), and parachute cord.

I have noticed a mpg difference. On the last trip I used the 0.100" disks I removed them half-way between OKC and Wichita Falls. I could only go 65 mph without the disks...where I could go 70 mph with them while maintaining the same mpg. I watched my MPGuino the whole trip...

[Specaled]

What would be the best way to secure the pizza pans to the hub caps, just zip ties? sorry if this has already been answered before,

[hoover]

My truck is a 2004 silverado with 16" factory aluminum rims. I used 1/8" abs plastic for my wheel discs. Took the factory center hub cap off and drilled a hole in the center of it. Then I filed the hole square, and pushed in a license plate plastic insert into the square hole. Used a license plate bolt to hold it. The steel bolt into the plastic does not seem to ever come loose. Just one more possible solution to this problem.

[brickinthewind]

Hey all,
Wanted an easy way to put smooth wheel discs/racing discs on, so I ordered these:

Full Moon Racing Discs for the 2004, 2005 and 2006 Scion XB | 15 inch | RMW-RD1-15-1110528

figuring eventually they would pay for themselves in mpg saved. Got up to 55mpg last summer on a tank after putting them on. After I ordered, a poster opined that they fall off. Well, I just lost one. The car was full of stuff and I cornered a little too fast (hypermiling of course) and I lost one. Where, I don't know, but I know why it happened. Heavy car, flexible steel wheel, inflexible hubcap.

Called Rocky Mountain Wheel back and they don't sell singles but asked me to call back next week as they sometimes have returns they can sell onesies and twosies of. I asked if there were any tricks to keeping them on more securely - they did have a good recommendation. Tweaking some of the tabs outward at, say, 12, 3, 6, and 9 o'clock so they hold more tightly there. Also, some guys run a bead of silicone on the inside but that has to be cleaned out every time you fill with air since there is no valve hole - caps need to be removed to reinflate. And he mentioned the racing guys just rivet them on.

Looks like I'm going to wait until they have 1 wheel cover in stock. Until then, going back to the OEM hubcaps. I'll tweak all the tabs next time I put the discs back on and see how that goes. If you do this mod, tweak the tabs out first!