What's next for the "Nut Wagon?"
 

This is a 1991 Honda Civic wagon. I think I've pretty much gotten as far as I can on driving technique. My best tank so far is 54 MPG. Mid to high 40s if I drive a little faster. Mostly rural highway driving. EPA highway is 32 new numbers or 35 old. I was getting 38 MPG without trying. I can probably hit 60 MPG, but a fellow motorist would probably shoot me before I burned the whole tank. I'd like to stay above 50 MPG and be able to stay close to the posted speed limit, which is usually 55 MPH. So I guess I'm looking for another 2-5 MPG. Possible?

Obviously I need to improve the car. I'd love to find a CRX HF 5th gear, should be good for about a 250 RPM drop in top gear. Should I add rear wheel skirts? Side skirts? Kammback? I'm not adding a full boat tail or belly pan. And I can't really lower the car or it will scrape on speedbumps and get stuck in snow. I currently have no outside mirrors, but I might add a small one on the driver's side since it's required.

Current (all untested) mods:
partial grill block (fan only comes on in low-speed traffic)
oversize front tires
increased tire pressure (slightly over sidewall max)
tires are mostly bald :D
hubcaps
air dam
no mud flaps

A grill block and rear wheel covers might get you a few more mpg's.

Nothing says "Nut" like a boattail, though, and a well designed boattail would definitely push you into the 50's with moderate hypermiling.

I would buy some tyres if they are bald, but bald tyres are illegal here in Scotland for obvious reasons. Did you know it rains quite a bit here ? :D

Do you have pics ?

Fumes,
I'd definitely go with rear skirts (or kilt). Here's how I did mine. Very easy.

You may also try a WAI, and since that air needs to go up pretty high to get over the car, I'd make a kammback as long as possible. Belly pan too. I'm sure you can consistently get >50 all the time at speeds similar to the speed limit.

It sounds like you've done most of the proven aeromods, and there's not too much room for improvement on the front and sides of the car, aside from the rear wheel kilts. Do you have smooth wheel covers on the front?

Buy it some Insight tires, extend the rear as far as you're willing to go, think about a block heater and an alternator toggle switch, and you're pretty close to done modding the Nutwagon, I think.

Bald tires aren't legal here either, but I get the car inspected in the winter with the snow tires on it. I'll definitely need new tires next summer. And I do have to slow down for heavy rain. :p

Pics:
http://img.photobucket.com/albums/09...twagonside.jpg
http://img.photobucket.com/albums/09...s/newblock.jpg

I'll have to be creative with mounting the skirts, there isn't much rear fender lip left on the poor thing.

I have no idea what the intake temp is, but it should be pretty warm already. I got rid of all of the tubing connected to the airbox, so it's sucking in underhood air. Which should be pretty hot in summer with most of the grill blocked off.

Front wheel covers are pretty smooth and the larger front tires fill the gap pretty well. Some kind of LRR tires are on my wish list, right now it has 185/65-14s up front and 175/70-13s in the back.

One small mod could be to remove or retract the radio mast and fit an interior one. Looking at the rear arch the car is lightening itself :D

Removing the extra lights and bar, or integrating them in the front spoiler ?

Fitting the license plate flat to the front spoiler, rather than having it stand off?