i have a 99 Accord EX with 4 cyl. and automatic trans. Just had it gone through...new cat, oxygen sensors, no codes now. After this work, I got 29 MPG the first tank. This is the second tank I'm on and I estimate it will be back to 24-25 MPG with exactly the same driving. i'm keeping a close watch on how drive, never over 65 on highway, and easy take-offs and stops.
What can I do to improve this lousy mileage?[&o]
thanks in advance.

 

there are a few ways to make sure you keep good gas mileage.... accelerate evenly at about 1/4 throttle, shift between 3500-4000 rpm's (on most honda's) let off your foot early on the gas and coast to slow down before applying brakes, a K&N air filter or SRI can also improve gas mileage a little bit....

 

Tire pressure too! I neglected this and 3 out of my 4 tires were way out of spec.

 

Was it windy? Seriously, I've noticed that a 15 mph or greater head wind drops my fuel economy by 10-20%.

 

I am doing all of these things to promote optimum mileage. I've also checked my tire pressure, brakes to make sure there's no drag, and am running a bottle of a premium fuel injector cleaner through it right now.
My driving (including wind factor) has been almost identical for both tanks I've checked.
I still can't figure out why I have a 5MPG drop in mileage between 2 tanks of gas.
Thanks for the suggestions!

 

My tire pressure is correct, and consistent.
Thanks

 

Thanks. You are right about the wind. In this case it was not a factor.
I don't know where to go from here..........[:'(]

 

this may sound like a dumb question but I have to ask.... there haven't been any times recently that you started your car and let it sit/idle to warm up has there?

 

No I haven't. I have done the tire thing, it doesn't miss or anything, and I'm going to pull the plugs to check them. The air cleaner is new, but I might fabricate a cold air intake and use a K&N filter and eliminate the air box.
The 5 MPG drop in mileage from one tank to the next is significant. I have messed with cars for many years and this kind of has me stumped for now.
Depending on the condition of the plugs, I may have a check with an engine analyzer to see if it dumps any error codes.
Thanks for the suggestion!

 

if you have not done it yet,, go to the top page of general tech and read up on the post , ( Improve gas mileage )