i have a 1992 honda accord mt 2.2l. It gets good gas mileage on highway but horrible in city. 30 mpg hw and about 17 in city. It use to get what it is suppose to get(22 to 25mpg in city). Spark plugs have been changed, air filter.
There has to be something that causes bad city but good highway gas mileage. Maybe a poor spark at higher rpm's while accelerating as to cause big ineffeciency in city cause there is alot of acceleration in city? I am just wildly guessing here.Does anyone know or can help?

 

Are you using the OEM spec spark plugs or have you opted for a non-standard spark plug?

 

I am using OEM ngk's(Brand New)

 

How long in both duration and miles are your typical "city" driving trips?

 

it varies greatly as most miles are city miles. I have noticed something over the past 10 months i have owned car about mpg on highway. I keep records on gas mileage consistently. Anyways if i drive a highway trip 80 or so miles and then start checking my mpg in city right after that trip. I get much better city mpg for a period of time. Ussually about a tank full or more. Its like the computer is telling the car a different fuel mixture after the highway trip. I wonder if this has something to do with things.

 

Check for stored codes.

Is the rest of the ign system up to date (cap, rotor, test wires)?

 

Any faults, engine light on?

 

I have same '92 5 spd car with now 213,000 miles. I get 30 - 32 hwy, ~27 in town.
My town is more suburban than hard core city (stop every block for a light) though.

Would guess your issue is one of 3 things:
* wrong tranny fluid, spec is for engine oil in tranny
* dragging brake
* urgency vs. throttle control; unless urgent I shift at 3000 rpm or below.



None of these explains a change in mpg though.

best.