Having a car that has high mileage such as mine 212K and I drive 500 miles a week, does this affect MPG?

The reason I asked is I noticed that I'm getting less now and I drive the same road every day and I do not have a heavy foot.

And messing with the timing of the car will you more or less on the mpg. retard or advance?

Air filter is clean and tires are inflated to Accord specs. Oil change every 3k.

Thanks!

 

Generally speaking, the more miles you have on the car, the less efficient it becomes.

You can always do a tune up/replace o2 sensors/the cat. Also make sure the brakes are not dragging.

What mileage are you getting? I typically get 21mpg w/ 114k miles

 

Is that right?

 

A well-maintained motor, with no excessive wear and tear, that is free of excessive carbon build-up, and that has components (and sensors) in good-working order should see roughly the same MPG as a low-mileage one.

All depends on the condition of your motor... At over 300,000 miles, my old '88 Accord was still getting the same gas mileage as when I bought it (used, with 50,000 miles). I bought my '99 Accord new, and even after 200,000 miles it was still getting the same MPG as new.

 

I agree. Currently sitting at 361,000+ on a 1992 LX. I lose about 1/3 qt. of oil (might be burn-off, might be slow leak though no stains on the drive to support this) between 5k changes and I still get 33-34 mpg, as I have for the past 17 years. As a side note, at 500 miles a week you could probably stretch your oil change interval, 3,000 miles in 6 weeks is light work for todays oils.

 

A lazy O2 sensor can (and often do) effect fuel consumption.
What happens over time is that it can't keep up with the rapid changes seen in the exhaust, and this inefficiency equates to poor(er) gas milage.
This happens over time and goes unnoticed until one day the questions asked; what happened to my gas?
Oh, and the real Pis^%%$r about this, It won't turn the CEL lamp on.

P

 

Not that P needs me to back him up, but I completely agree with him. My first thought about your low mileage situation (although I forgot to post it) was that you had a lazy O2 sensor. I can't tell you home many times I've seen this happen...

 

One other thing that is usually not mentioned, is to change the pvc valve. When I had a 5th gen Accord, I changed the pcv valve and the gas mileage increased by 2 mpg. I gave the car away to a nephew at near 300,000 miles, the gas mileage was still very close to when I had bought it new. It was a 5th gen Accord EX, automatic, and averaged 29 mpg.

 

PCV Valve? Could you tell me where to look for this.

As for the O2 sensor I just replaced the thing 8 months ago! Do you need to keep replacing the thing. And when replacing the O2 sensor do I look as the same thing as the Spark Plug?

Right now I just put my timing mark a little on the retard side turning it 1/8 per turn and see if that helps. But again I might not be happy with the cars timing that way.

Oh also on 200k I replaced the rear main seal and have replaced the oil pan and gaskets. And the spark plugs was done at 210k

 

210k 90 accord still getting 33-34

 

as someone else mentioned the catalytic converter can also cause this. if its clogged it can reduce your mpg. i would start with the pcv valve first though as its cheap and should be done somewhat regularly (some advise to do so at every tuneup). i'll try to look up the location. i should do mine anyways

 

the pcv is in the middle of the head towards the back of the engine. it is "L" shaped and it has a hose on one end and the other end goes into the block. if you would like a pic i can post one

 

The pcv valve is located on top of the valve cover, near the middle back. It is a simple replacement.

 

If you used a non-Honda O2 sensor, you may (indeed) have a bad one. I've seen aftermarket examples fail anywhere from 3 weeks to 3 months from installation. After making good on warranty repairs for these, I made the commitment to use either OEM Honda or Denso units.

P

 

My 95 Honda with 359,270 miles on it has constently averaged 27 MPG.

Gary

 

Can't vouch for the '95s but my '92 EX with 125k miles still gets 28-32mpg with 90% over 55mph driving. My dad's '91 LX with 206k miles still gets 29-34mpg with 75-80% over 55mph driving. All I can figure is he's a little lighter on the acceleration than I am. Both use a small amount of oil (average about a quart every 3k-5k miles depending on which car)

I will admit to not being "easy" on my car. It sees 4k rpms + every few weeks thanks to crazy cloverleaf interchanges with no merge room...

Also of note, I picked up an mpg or so by replacing the PCV Valve on the valve cover, cleaning the IACV and adjusting the FITV. All of these take less than an hour worth of time to do and are quite simple. Never really was sure what gained me the extra mpgs 'cuz I did all of those within a tank of gas...

 

will try the PCV approach. I have used a Honda O2 sensor.

How much do you think the PCV valve cost?

 

a pcv should be cheap. like under 20 i think the last one i bought was like 10. that was for an 87 dodge ram 50 though. (i know... GHETTO!!! lol that one is resting in peices now in someone elses front yard.)

 

A Honda PCV valve about $17-$20.

An aftermarket, about $4-$10.