smyroad

I had the car in for the 45K service three weeks ago and afterwards I noticed a drop in my gas mileage from 25mpg to about 23mpg. Last week I drove down to florida and got 29mpg, used to get 30+. On the way back I only got 24mpg. I changed the air cleaner on the way back up and it did not seem to make a difference.

The engine still feels strong and runs smooth at idle. The low speed hesitation seems more noticeable even occurring up to 15 miles and hour.

Any ideas?

Also on what I think is unrelated, I noticed this morning that while the clutch is engaged in neutral I can hear a "shhhh' noise. Any thoughts on that?

xviper

Have you ever had your injectors cleaned? Or even used injector cleaner in the fuel as routine maintenance? Did they do anything with your sparkplugs? They may be dirty or in need of re-gapping. You could have also gotten a tank of poor fuel with a previous fill. It could take a few tankfuls to get rid of all of it. If you happened to fill up right after the tanker filled up the gas station holding tank, you would have pumped in a lot of crud. This can have a detrimental effect on your fuel economy.

As for the clutch thing, I've noticed this even on new S2000s. It could just be the sound of the throw out bearing and the tranny gears and shafts spinning around. You may just not have noticed it before. It's possible this noise has gotten louder as the car ages. Clutch action and shifting seem OK? When was the last time you had the tranny fluid changed?

dookiewhat

damn, you still get better gas mileage than me! I get like 21 mpg...

DimaK321

MPG depends heavily on driving style
i usually get 18+MPG, but then again I VTEC all the time

smyroad

I'll check the plugs and try some injector cleaner. Did the gap change with the plug recall?

mad-dog-one

I understand that there is a switch from the Winter-blend to a Summer-bllend of fuel that takes place about this time each year, although I don't know if this applies to your area of the country or exactly when it takes place. If the timing corresponds to a change in fuel blend, the service that you received might be a coincidence. I'm just looking for a silver-lining for what might otherwise indicate a more serious problem. Good luck and let us know what you find.

smyroad

It could just be the S trying to keep me from leaving florida

smyroad

It's been about 8 tanks of gas and my mpg has returned. I took a 300 mile round trip to UVA on Wednesday and got 32mpg.

I guess it was either a bad tank, or the S trying to adapt to the summer gas blend.

smyroad

Gas Cap!! Took about 3 months for the CEL to report Evap Emissions code.

New gas cap is tougher to tighten then the old one.

Gas mileage is now consistent again.