Hello
 

Hi everyone, I'm Scott. I've been lurking for a few weeks and enjoying what I'm reading. I have a 94 Civic DX coupe with the D15B7 engine and manual trans. I love the car, it will be passing the 187,000 mark next week. Work is 66.5 miles from home so I'm putting between 670 and 700 miles per week on it. I've put about 63,000 miles on the car since I've had it and am averaging 41.17 mpg with over 95% highway and less than 5% city. The average was over 42.5 but I had a bad rotor or cap during this past winter and didn't realize it until the motor started to miss from time to time. My mileage dropped to the high 30's during that time. Never will buy a cheap cap and rotor again. :) Other than making sure the car is in good mechanical shape, the only things I've done so far have been adding factory cruise and increasing the tire pressure to the max specified on the tire which is 35#.

I'm thinking about doing some aerodynamic work on the underside if the car especially back by the drivers side of the fuel tank where there is a big gap. Can someone suggest some materials I could use to accomplish this? I would prefer to use some stiff plastic if possible.

Thanks and looking forward to 50+ mpg with your help.

-- Scott

This is a good place to start with the underbody: https://www.gassavers.org/showthread.php?t=671

Another member, basjoos, has also done one like this but with aluminum over the exhaust area rather then a gap.

Good luck with the car! How fast are you driving?

Thanks for the tip! Depends on where I am in my route as to how fast I'm going. The first 10 miles are on country roads so I'm not using cruise usually and I'm going anywhere between 45 and 55 mph. The next 10 miles I'm using cruise set at 61 mph. Next is freeway driving where I'm right at 65 in cruise in a construction zone for 15 miles then at 71 mph for the balance of the trip. Try to drive it the same way every day. Shift at a low rpm just fast enough to not lug the engine.

-- Scott

Sounds like aero mods are right up your alley then. Also, consider putting some more air in your tyres. There are lots of little nitpicky things and some really big things also, but I think aerodynamics will help the most besides driving technique, which is really big but sometimes difficult depending on traffic/flat highway.

my best aero mod was cutting 4 inches off of the rear bumper. free to do and takes 2 hours if your maticulous and want it looking clean. i should take pics.....

Please post pics. I want to see how clean it is. Also post a description of the techniques used.

I'd be interested in seeing this also. Can you describe what you've done and how much mpg you've gained?

Thanks!

-- Scott

mpg appears to be .5 to 3 mpg i know it did something though. ill make a thread, but im going away for 2 weeks... so it wont be until mid july. started with a reciprocating saw(sawz all) then decided a circular saw would make a much cleaner cut.