This is my first time posting. (Please be polite if I have posted in the wrong forum or done something incorrect)

I just purchased a 1994 Cutaway that was converted on the interior to an RV. It's a 7.3 IDI single rear axle with 258,000km (160,000 miles).

I logged 600km on my maiden voyage and everything seems to be tip top. I'm about to have it inspected and will begin modifying/maintaining/upgrading this week.

A couple concerns:

Given that I will NOT be towing/hauling I would obviously like to reach my best fuel economy. Currently doing approx 15-17mpg HWY which I understand is good but I'm confident I can do much better. I drive very conservatively and am never in a hurry, 80% highway miles.

I've done a bit of research and am wondering if anyone has any specific advice/suggestions regarding improving this model van?

One problem I have is that I can't stand up in the van without bending my neck slightly and I would really like to add a 12" raised roof to allow head clearance (and possibly improve aerodynamics??).

Looking at the front of the cab it seems like an airfoil or something would really improve the dynamics for my highway driving. A raised roof/hi top conversion would give me the the head clearance I need to stand up but if it's only starting at the box and not the cab it's not going to improve my aerodynamics. In fact, it will probably make it worse. Adding a raised roof to a vehicle this size is going to be an issue in itself, any suggestions welcome. (Yes I understand there are RV message boards where I could pose that question).

I've read that three starting points for me will be adding a large diagram exhaust, cold air induction kit, and a programmer for the computer/plug in -unit (although im not even sure that means).

Any help greatly appreciated, thank you.

<a href="http://tinypic.com?ref=a1pvll" target="_blank"><img src="http://i46.tinypic.com/a1pvll.jpg" border="0" alt="Image and video hosting by TinyPic"></a>

 

Nice looking RV/van. 15-17 mpg is pretty good considering the vans aerodynamics. What transmission is it running? Do you know what gears you have in the rear end? How many miles are on the IP/Injectors?

The intake and exhaust would be a good idea. If the IP/injectors are old then they should be replaced. At the very least you should have the timing checked. For the aerodynamics you could install a front air dam to reduce the drag.

And the 7.3 IDI's don't have a computer, so the plug in tuner is a no go.

 

your best FE increases would come from a custom built front air dam,made low enough to match the lowest most component of the underside,skirting in your wheel wells, and adding a boat tail.also search partial grill block (be sure to have a real temp gauge) and perhaps a full or partial underbelly pan to clean up the underside. everything after this list,will fail in comparison to these,especially since your 80% hwy.your single largest gain will be the boat tail for that rig im betting.focus a lot of time and effort on that one.
be sure to research here:
Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

don't forget basics such max tire pressure,proper wheel bearing maintenance,synthetic oil's everywhere you can afford them.mainly the gear lube in the rear.

 

Welcome to the forum! Nice looking van! I would check your rear end gears, there should be a tag bolted to the cover. The only programer you could do would be to the transmission (shift points, tow mode, etc.) because the engine is not computer controlled. Not sure the exhaust or cold air intake would give more than a couple of mpgs. As far as the roof it looks like you're allready at 12" raised.

 

What did you use to fab up your air dam? I was wanting to make one for my '88 E250.

 

a 92-97 (9th gen) basic old school aluminum running board,made to fit a super cab.
flattened out by running it over with my truck lol.on the bottom,i used flexible garden edge trim to match the bottom of my front axle.

https://www.ford-trucks.com/forums/7...l#post10608863

with proper aero mods,a big rig owner can trump FE of an old 460 gas pig pickup truck!
http://ecomodder.com/forum/showthrea...ort-20704.html

 

Thank you very much for the reply, I'm not sure what transmission and what gear ratio but I will have that checked at inspection this week. The front air dam is a great idea. Never thought of that.

 

This is a great help. Thank you!

 

Unfortuntely I can't stand up fully in it (the guy who brokered the deal for me told me I would have head room but when I met him I discovered he's only 5,2" lol. Needless to say I'm near 6 feet tall in boots).

So I really need to find a way to cut out the top of the roof and add another 6-12 inches.

 

How are your fabbing skills? Or a body shop should be able to help you. I think it my hurt your MPG though.

 

Thanks for the link....the fact that you flattened it with your truck is awesome.