Opinion on wheel discs for Ford C-Max

[Recumpence]

Hey Guys,

I am at 20,000 miles on my C-Max and averaging in the high 50s mpg (around 56mpg most days). I love this car!

So, I am beginning the aero mods. First on the list are wheel discs. I have looked on-line for pizza pans and have found some nice looking spun/brushed aluminum pans that should be ideal. The two questions I have for you guys are;

#1 My rims are 18.5 inch at the lip. Should I go with 19 inch pans and allow that extra 1/4 inch all the way around to just overhang the rim edge or should I go with 18 inch discs and let the edge of the rim show?

#2 What would you say would be the best method to attach them? My rims are forged aluminum with 15 spokes. If these were cheapo rims, I would just drill and tap holes into them at high strength areas. But, this is a brand new car with expensive OEM rims. So, I want input from you guys about the best way to go about this.

Oh, also, the car has a belly pan that covers most of the underside. However, from the rear wheels to the rear bumper, it is totally open (Jimmy Hoffa could fit up there) Anyway, I am going to TIG an aluminum frame together to hold Coroplast there to complete the belly pan. I am hoping for 1mpg gain there and another 1.5 or 2mpg with the discs. Of course, who knows what gains I will see until I try?

Matt

[MetroMPG]

Fun to see a C-Max owner getting into modding!

Have you already done partial grille blocking, or does this car have OEM automatic shutters?

As for a non-destructive, reversible attachment method for the wheel discs, have you seen EM member Vekke's zip tie 'caps'?

[WesternStarSCR]

Originally Posted by Recumpence

#1 My rims are 18.5 inch at the lip. Should I go with 19 inch pans and allow that extra 1/4 inch all the way around to just overhang the rim edge or should I go with 18 inch discs and let the edge of the rim show?

#2 What would you say would be the best method to attach them? My rims are forged aluminum with 15 spokes. If these were cheapo rims, I would just drill and tap holes into them at high strength areas. But, this is a brand new car with expensive OEM rims. So, I want input from you guys about the best way to go about this.

Matt

1. Definitely 18" pans for your 17" wheels. My 17" pans leave just the rim open on my 16" wheels.

2. Hard to suggest a different attachment method when using aluminum. Need To secure it better than if discs were plastic due to danger to others if you lose one.

I am going to drill and tap mine. But my car is 9 years old and my wheels and my plan should work well. Maybe plastic would be better for you with zip ties.

Here is my last update on my pizza pans with pictures and plan:
http://ecomodder.com/forum/showthrea...tml#post343362

[Xist]

If you are getting more than twice the mileage that I am in a car with fifteen-inch wheels, should I go get seventeens?

[Recumpence]

Originally Posted by Xist

If you are getting more than twice the mileage that I am in a car with fifteen-inch wheels, should I go get seventeens?

22s...

[Xist]

There is a Lumina or something over here with the monster truck treatment. I will try to remember to get a picture.

[WesternStarSCR]

Matt,

I was thinking about this driving down the Southfield Freeway today...

Not sure how 'flat' of a surface you have facing outward on on your C-Max wheels. But if you have some flat surfaces, maybe look into 3M Dual Lock. It is like Velcro, but better and more rugged etc. Each side is the same as well. It is used in industrial applications, and we use it to mount expensive test equipment inside the cabs.

Then perhaps some coroplast or acrylic or even cut the bottom out of a plastic oil drain pan to use as discs.

Also...

Here is a fabric based one we use at work on our Freightliner Cascadia test fleet. Supposedly, during testing, they got approx. 0.25% better FE per wheel.

Sometimes they only put them on the 4 tractor wheels, for a 1% gain.

If they have it on all 4 tractor and all 4 trailer, they are getting close to the gain the manufacturer states, for a total of 2% FE gain.

Aerodynamic Wheel Covers | Tractor Trailer Wheel Covers | Deflecktor

Cheers,
Sean

[Recumpence]

Funny you should mention that......

I have some of that 3M "Velcro" here. I considered using it. Actually, what I may do is this;

(My rims are flat on the outside edge)

I may order some 1/16" thick G10 (G10 is like carbon fiber or fiberglass) and use it with the 3M lock around the rim edge. G10 is so light, it would not take much to hold it on.

Matt

[Xist]

I had just walked seven miles and was not home yet. I was not crossing the street!