2000 Honda Civic Loss of gas mileage almost 9 miles/gallon

Good morning everyone,

Thanks to everyone who responded to my other questions last week, I do appreciate it.

I have a 2000 Honda Civic with 63,000 (approx) miles. I have always gotten around 38 miles/gallon regular driving and about 42 miles/gallon highway. I took a trip this weekend and only got 33 miles/gallon and this was after new spark plugs and an air filter. I knew before this service I wasn't getting as good a mileage as before but thought with new plugs and air filter it would get better...well it didn't. I called the Honda dealer and they are basically now blaming the winter gas blend, the weather, and new tires I had put on a few months ago.

I have put fuel injector cleaner in several times which doesn't seem to help.

Any suggestions?

Thanks
Kris is there an engien light on. I would suspect either a leaky fuel injector. A cam position sensor or a o2 sensor. Any more info could help us narrow it down. No there are no engine lights, no dash lights that come on at all.

Thanks
Kris I just got back from the Honda dealer. They took it for a drive and said they could not feel any resistance or hesitation or less power while shifting or driving. They put in this expensive fuel injector stuff, suppose to be better than the stuff I would buy at a regular store...suppose to clean the injectors and fuel system. We'll see. The service guy also said to keep the speed down that anything over say 70 miles/hour uses more gas, etc. So I'll try. With gas prices the way they are I want good gas mileage that's why I bought my Civic.

Thanks
Kris please let us know if this ends up being the problem. Will do.

Kris So far the first half of a tank I only get 31 miles/gallon. That's not good. I used to get 38. I'll wait until my next fill up and see. If it does not improve I guess I'll have to take my car some place else because that shouldn't happen. I only have 64,000 miles on my car.

I used to get 42 miles/gallon on a trip and 38 miles/gallon every day driving. Now I'm getting 33 on a trip and 31 every day driving.

Kris Ok, I have had two more tanks of gas since. The first tank got me 35 miles/gallon and the last one got me 37 miles/gallon. So I'm happy. I'm not sure if it's the fuel injector stuff the dealer put in or my driving has changed. I am consious now of how I drive. I have a standard transmission, so I shift at no more than 3000 rpm and I've been keeping my speed down. So maybe it's a combination of things. My daily driving is some highway some city.

thanks
Kris lol my car gets 7 miles to the gallon. You should feel so lucky.. You must make good money!

I could never afford a car that got 7 miles/gallon You have to pay to play =-(..

Nothing fun is ever free.