94 Civic EX Coupe

[ampegbassplayer1969]

Hey guys! I first found this site about two years ago and it helped me gain a few miles per gallon, but I decided today that it's time to register for an account. I've got a '94 Civic EX Coupe 1.6vtec that I just put back on the road today after a few unfortunate events. I wouldn't really call myself a hypermiler, as I don't feel comfortable with many of the techniques, and think that some would lead to excessive tire wear and would be pretty dangerous on PA back roads (Blind driveways, hills, deer).

Anyways, last time I drove it a year ago I was averaging 36MPG (mostly back roads, hilly Pennsylvania), and had tanks as high as 39mpg. This seems low for a car like this. I drove my fathers 94 Civic LX Sedan and have gotten as much as 44mpg on 300 mile tanks fairly easy by accelerating slowly with paying special attention to being VERY light on the pedal & doing plenty of coasting.

I bought my car as an automatic, and my father and I converted it to manual over a 2 month period - never thought to get a new computer for it, I'm still using the automatic computer (Not sure if that has an effect on mileage?) and I'm still using the original O2 censor, and it's probably about time I change that out too. I don't see why I shouldn't be getting at least 38mpg tanks consistently with the way I drive compared to other civics I've drove.

Would any of you feel it's necessary to upgrade the air intake also? I'm still using the stock airbox. I'm running at 36lbs of pressure per tire on 14 inch steelies also.

What are some other tips you guys have for civics?

I'm looking forward to learning from your experience and especially saving some $$$!

[theholycow]

I do not think that upgrading the intake (anywhere in front of the throttle body) matters. There a bunch of links in my meta-sig about it. In short
- testing shows that even a severely clogged air filter doesn't reduce fuel economy
- if you think about it, a restrictive intake is like a closed throttle
- even that doesn't matter because you likely keep the throttle closed anyway
- even if you don't, it won't matter until very high RPM (and if you're using very open throttle at high RPM then you don't care about fuel economy)

Is 36psi the recommended pressure, or higher? Have you experimented with higher pressures?

[ampegbassplayer1969]

Originally Posted by theholycow

Is 36psi the recommended pressure, or higher? Have you experimented with higher pressures?

I've seen recommendations in different places for this car from 30psi to 34psi, so I figured 36 would be pretty safe. I suppose I could squeeze another pound or two into the tires and see what happens. How much do you guys overinflate your tires?

And thanks for the info on the air intake!

[ampegbassplayer1969]

Also - I was wondering if anyone here had any success of modifying a ScanGauge or something similar to work with 92-95 civics?

[theholycow]

By "recommended pressure" I meant the pressure that's printed on a label on the car (probably in the drivers door jamb).

I run the highest pressure that doesn't result in reduced traction, harsh ride, or severe center wear. In practice, with my relatively heavy cars, that usually means the tire's maximum pressure (which I try not to exceed). In a Civic you may reach one of the aforementioned downsides before you reach the tire's maximum.

I've never heard of anyone modifying OBDII equipment to work on a non-OBDII car. There are some alternatives available. One is called MPGuino, I think there's another whose name I don't remember, there may or may not be something that allows you to connect a laptop computer to your car, and then there's individual gauges that you can install (including an ugly DIY relative fuel rate display, linked in my sig; it is of limited usefulness).

[ampegbassplayer1969]

Originally Posted by theholycow

I've never heard of anyone modifying OBDII equipment to work on a non-OBDII car. There are some alternatives available. One is called MPGuino, I think there's another whose name I don't remember, there may or may not be something that allows you to connect a laptop computer to your car, and then there's individual gauges that you can install (including an ugly DIY relative fuel rate display, linked in my sig; it is of limited usefulness).

Interesting. I'm going to check this out. My last tank was 38.9 MPG, not bad for all the hill driving!

[bowtieguy]

my highest trip ever was loaded w/ hills. it's a great opportunity to achieve super MPGs...if driven correctly!

[CoBaker]

Originally Posted by ampegbassplayer1969

I bought my car as an automatic, and my father and I converted it to manual over a 2 month period - never thought to get a new computer for it, I'm still using the automatic computer

You should get the manual P28 ECU for it.
When was the last time this had a basic tune-up: air,fuel,oil filters, oil change, plugs/wires?