91 LX wagon mpg

[Dhorn33]

I have been driving my 91 Accord LX wagon for the past 3 weeks now and my gas mileage doesn't seem to be as good as I was expecting. It has 232k miles and is an automatic. I run the tires at 35 psi and I have replaced plugs, pcv, air filter, cleaned out the iac valve and ran a can of seafoam through a tank of gas. I also installed a brand new radiator and t-stat due to a leak. The best I have gotten was 24.7 driving 65 - and the worst was around 21 but so far the average is around 22.5 mpg. Is there a speed or RPM that this thing does better (at 70 mph the tach is around 2900)? I drive around 60 for the last tank and only got 22.2? Should I try driving faster for a tank and see what happens? I was hoping for at least 25 mpg consistently - maybe unrealistic? By the way I live in MN and temps have been 5-30 degrees. Thanks!

[NAiL05]

Try cleaning your EGR/ports and stuff see if that helps a bit. Wagons are a bit heavier so might take up a lil gas but thats just my guess. There are quite a bit of people on here with wagons so you can ask them see what they are gettin around. Are you carrying a lot of passengers or objects? That can also contribute to more gas. Do you have a lot of mountains and such around your area go over hilly roads? Those could be causes.

[koffin]

I have been driving my 91 Accord LX wagon for the past 3 weeks now and my gas mileage doesn't seem to be as good as I was expecting. It has 232k miles and is an automatic. I run the tires at 35 psi and I have replaced plugs, pcv, air filter, cleaned out the iac valve and ran a can of seafoam through a tank of gas. I also installed a brand new radiator and t-stat due to a leak. The best I have gotten was 24.7 driving 65 - and the worst was around 21 but so far the average is around 22.5 mpg. Is there a speed or RPM that this thing does better (at 70 mph the tach is around 2900)? I drive around 60 for the last tank and only got 22.2? Should I try driving faster for a tank and see what happens? I was hoping for at least 25 mpg consistently - maybe unrealistic? By the way I live in MN and temps have been 5-30 degrees. Thanks!

Before swapping in my H22 I averaged 29MPG. My wagon was a 5spd and I drive %80 highway. I shift at like 2500RPM when concerned with economy.


My suggestions:
Run a can of Seafoam through your PCV into the intake plenum.

Also, you're an auto, so you are hampered by that. Plus being in MN(me too) we lose a percentage of economy due to winter blending of fuel and long periods to get the car to operating temps.

Pump up the tires to 40PSI.

How long do you intend on keeping the car? If awhile, look into this product:
www.auto-rx.com. I love it. I have used it in many vehicles, all with positive results. It is spendy, but well worth it.

What weight oil are you running? 5w20 would be an excellent choice. You should gain around 1-2 MPG with changing that out assuming you are running 5w30 or 10w30.

Buy some Gumout Maximum fuel system cleaner and run 1 bottle in a tank for 2 tanks. For one of the tanks, give it an "Italian tuneup". Drive it fast and hard. Clean out some of the built-up carbon. It is good to do this from time to time.

Then there are other things you can look at like, valve lash adjustment, timing, alignment, weigh reduction, and replacing to synthetic fluids.

If you don't know the history of the car, I would also replace the plug wires.
If you need some, I have a set from my F22 engine I can sell you.

I think you are on the right track and not far off. A well running auto wagon should get around ~27-28 with mixed driving regardless of how many miles are on the engine.

If you REALLY want to get into MPG. Start making some aero mods to cut down on your drag coefficient.

Good luck!

[Dhorn33]

I read a thread on cleaning the EGR ports - the one that involved drilling holes and pulling the plugs out. Is this worth doing and will it have any benefit on fuel efficiency?

I put 5-30 oil in the car when I got it and it does leak so I wasn't planning on changing it again until after I do a timing belt job and adjust the valves, etc. I will try 5-20 on the next oil change.

I will also try to pump tires up to 40 and see what happens. I know the alignment is off because I get a slight pull to the left and I replaced the front struts and an upper control arm with used parts a couple weeks ago.

I don't think I will be keeping this car all that long - I was actually hoping to get a car that gets 30+ mpg but I stumbled on this one while shopping and since I always like the looks of these I thought why not? Maybe if I can get mileage up I will hang on to it. Thanks guys!

[NAiL05]

Yes cleaning up the EGR makes a difference. You dont exactly drill all the way through the ports you just drill enough to wear you can thread on the bolt and pop em out. Honda has a kit for it. But The ones that were already in there are usually the best ones as I have heard. But 5/30 and 5/20 shouldnt be much difference. I would just stick with your 5/30 since you are already using it and such. Alignments can screw with your mileage a bit too depending on severity of it but yea. Try some of that and see if it works.

[Dhorn33]

I drove 100 miles yesterday of mixed highway and city and got 24.4 so that is a little better. I will keep trying things and updating this as I go.