bad mpg cavalier 2.2L - Fuel Economy, Hypermiling, EcoModding News and Forum

sol · 10-22-2011, 01:14 AM

Hello everyone I have a 1991 cavalier 4 cylinder 2.2L but its been getting real bad mpg about 17 to 19 on average I've changed the spark plugs, air filter, tire pressure is good and I've added fuel injector cleaner. I even drive like an old lady and that didn't help bring up my mpg. I cant think of anything else that could be causing bad mpg Amy ideas?

deathtrain · 10-22-2011, 01:23 AM

how many miles and have you done a compression test?

jakobnev · 10-22-2011, 06:27 AM

Does it show any symptoms of actually running badly?

And driving like an old lady doesn't get the best mileage, far from it. You have to get up to speed swiftly, but make sure you get off the gas in time for when you need to slow down.

sol · 10-22-2011, 06:48 PM

It's got 93k miles and no I haven't tested the compression I will next week. The only thing is that I have to crank it for like 5 sec for it to start.

sol · 11-27-2011, 02:07 AM

Well I changed the o2 sensor and the coolant temp sensor i hope it helps

deathtrain · 11-27-2011, 02:29 AM

compression test time then

jaguars · 11-27-2011, 11:10 PM

i have the same car and my problem with it is that my temp gauge never reaches the middle its ita just reaches 1/4 of it.

roosterk0031 · 11-28-2011, 10:47 AM

How quick does it heat up, a new 195-205F t'stat might help. With a auto really slow acceleration might actualy hurt MPG in my experience, try accelrating quicker to get it into drive faster.

How's the brakes, old rubber hoses at each wheel can restrict the fluid from returning causing the brakes to not release completely. I recently had to replace one on my 03 mailbu so your 20+ year old hoses & brakes could be holding you back.

sol · 11-29-2011, 10:36 PM

I replaced front brakes and guide pins the hoses are cracked but don't leak

Compression results

Cylinder: 1 2 3 4
Dry: 160 159 160 160
Wet: 185 185 190 190

Ford Man · 11-30-2011, 01:09 AM

Compression looks like you have a healthy engine. My idea was a new 02 sensor, but I see you've already replaced it. Besides checking the brakes to see if they are dragging you might check to make sure all the wheel bearings are in good condition and rolling freely and have the alignment checked. Did you change the plug wires when you changed the plugs? Could be a bad wire. Might also check to make sure all the fuel injectors are working. What type of driving are you doing? Highway? City? Combined? CEL on? Also check for vacuum leaks. What's the condition of your battery? I've seen my FE drop when my battery was getting weak, probably because the alternator was working overtime trying to charge a battery that was about worn out.