Looking For 45 MPG.
 

After having my 92 Civic DX (1.5) 5 speed for almost 2 weeks I have come to the conclusion I don't want to "Hotrod" this car. I would rather just see how many MPG I can get out of it. So far the best MPG out of a mass production car I know of was a 92 Metro that was getting 58 MPG. But its not that reliable and not as many are around in comparison.

All data will come from running around 100 miles of a full tank of 87 octane with no hyper miles. Hyper miles will come into account if I get desperate to make my goal. This will also be a totally stock car other than the mods listed here in this thread so others can do this if desired. The point is that newer is not always better. Most hybrid owners don;t even know that in 1992 the metro kicked the butt of the hybrid they spent so much on today.

So here is my base line. 37.4 MPG totally stock.

Next I will post data after running a standard K&N filter in the stock box. This will take about a week as I need to top it off tonight and run another 100 miles.

Other than the filter I am open for suggestions for what to do next. I can not stress the goal enough. Not fast, not expensive. Just MPG. While I know power brings MPG until the point that you have to up fuel PSI, for the most part.

I was thinking exhaust? But whats not very fair to others is that in my state we have no inspections and I can run a full off road exhaust. Would that be cheating?

Update: Not sure how the car did it but the first test results are in.
With just a K&N filter in the stock box (real cold air) she clocked 50.7mpg. I am dumbfounded at this result or +13mpg but its real numbers. One thing I did notice is that the speedo reads 3mph fast (per gps) so its not the truest number but its still 13mpg gain with nothing changed but the air filter.

For comparison my z24 cav only gained 3mpg with the specter air filter but the numbers on it are much lower. Started at 27 and ended up with 30 on it.

What are your base standards for measurement of MPG? That's an unlikely jump for an air filter. Are you filling the tank each time at the same pump at the same temperature to the exact same level before each run? Is each test at the same temperature and exactly the same speed?
I mainly wonder about the fuel filling. It would only take 1 gallon of fuel variance to throw your numbers off that far.

I filled it then zeroed the tip meter. Drove for about a week (80 miles or so) the filled it again. At this point I got 37.4.
When the filter came in I put it on right away and filled up. Again resetting the trip meter and going about a week. This time I filled at a different station at about 108 miles. After doing my calculations I was floored and went to make sure it was really full. Put in .2 gal and seen it try to poor back out. It was really full.

As far as temp goes. The weather did get warmer for like half of the last test. So maybe the air was less dense for 3 days making it more arrow dynamic? I don't know but all I can do is go by the numbers. I expected maybe 5mpg but 13 is crazy.

You probably need to do 500-1000 miles with and without the filter to get a better reading. That would be very impressive for a filter to do that.

Hey, I was wondering if there was an update to your mpg after the air filter mod since it's been a couple months?

Ya. For some reason it averaged much less when filling from an empty tank than just driving 100 miles and topping off. With that being said the project is taking a back seat. The wife and I loved this car at first but have decided to get something else. Wish I had something better to say lol. Its just a turd.

Aww, well I'm sorry to hear that. I have a 2003 civic that I really enjoy, and tend to get about 37 mpg driving mostly highway miles to work and back. I was trying to figure out if I can squeeze a couple more miles per gallon in by adding a cold air intake system or something... so your K&N filter idea sounded nice!

Every car I put a high flow filter in has gotten more MPG so I would do it. We have a 98 Cav Z-24 and it picked up 3-4 mpg with a high flow. Pretty much anything you can do to make something fast without having to add more fuel pressure will make more mpg cause you don't have to mash the pedal to get going or keep a certain speed on the hwy.

My 1986 Mustang GT was getting 32mpg hwy with stock gears. That was before I took it to the next level. Then I had to add 9psi of fuel pressure and its no longer a daily driver : ).