>>BIG<< project- hoping for everyones participation!

[metroschultz]

Originally Posted by TheSilverBullet

very nice paint job !

I agree, and I think we are "Mature" enough to see the right side.
I, for one, got my curiosity piqued when you mentioned that.

[micondie]

For better aero you could look into a wing over the cab like 18-wheelers use to direct air flow up and over the box. Judging from how many I see on the road this must be effective since I can't imagine the big trucking companies spending the money for nothing

[donee]

Sorry if somebody has suggested this already - can you chop the cargo box? What is your absolute min cargo height requirement ?

[Big Dave]

OK. Where to start?

I don't think 20 MPG is in the cards unless drive at speeds that would get you shot/arrested on the Grapevine. But you can get improvements.

At 5 MPG I'd bet you are wildly overgeared. Probably a 4.56:1 axle. For that truck maybe you should think 3.73:1.

Check your brakes. Sintered metallic brakes rust on the edges and swell up, causing drag. Easy to check. Jack up the front end and give a wheel a spin. If it spins easily, that isn't your problem. If it stops in less than 2 revolutions remove the brake pads and use a grinder to chamfer off the edges. If one drags, probably all four drag.

The wing thing on the cab is effective. You need to fair in the undercarraige, especially under the cab. A proper boattail might be 590 feet long.

If you don't want to come down long grades like a Dauntless at Midway, a US Gear exhaust brake will help a bunch.

[Frank Lee]

IF the radii on the front and top of the cube are large enough I wonder if a cab deflector would do anything. Those deflectors are mainly for shooting the flow over the tractor-trailer gap, of which there is none here.