I have a 90 hatchback 1.5 ltr 4spd manual and here recently I've been averaging 22 mpg city and highway. I was getting 32 not to long ago... Plugs and wires were changed bout 4000 miles ago along with fuel filter. Air filter about 2000 miles ago. Tires are properly inflated...what do you guys think?

 

check your compression if you can. bad rings will cause you bad gas millage as you get blowby. thats wierd though as well, i have a d15b2 with a y7 head and i get about 23-25 city and around 32-35 on the highway with my 4 speed.

 

make sure your thermostat is opening properly and your car is getting up to proper operating temp. if not the ecu will add fuel to compensate for a cold engine.

 

o2 sensor

 

scan for codes

 

double check your fuel filter, sometimes during the change out if the lines weren't purged any crap that was in the line can immediately clog the new filter. Spark Plugs gapped correctly? check voltage, and your CatConv could be stopped up if you have one, thats all I got on that one man...

 

Make sure your thermostat ground is clean.

 

what size tires are you running also? even with my 215/35-18's i still got my typical millage out of her. i noticed with my 13's on for the winter i dont get as good as gas millage as i do with my 18's. i know it wierd, but tire size plays a big roll.

 

thanks guys for your help...much appreciated

 

I don't know man, lots of people say they get worse gas mileage with the bigger rims

 

thats what i thought as well. i was well surprised to see no real difference in my millage. i think its also very weird. then again at 60lbs a wheel/tire, the rotating mass isnt that large on them. my friends 17's weigh almost 18lbs more than my setup and his robbed me of millage like crazy.

either way, whiteformula98 you figure out your issue yet?