Thread: Engine runs fine, maintenance is up to date, but I'm getting terrible gas mileage?

Ok, so my se-r is getting about 250 miles per tank, and I don't know why.
-Maintenance is up to date (newer spark plugs, wires, air filter, fuel filter)
-I'm driving very easy

When I turn my car off, sometimes I can smell fuel. But not all the time.

What are the common causes of bad gas mileage? Dirty MAF? Vacuum leak?

Gimme some diag ideas please.

Thanks guys.

I assume you have no leaks? First thing I thought of is it could be either a bad sensor (MAF, 02, or otherwise) or a leaky injector. Usually if you can smell fuel, though, you're losing it somewhere between the tank and the engine. Still, lots and lots of possibilities.

I had a leak in the gas tank vent hose a while back. I would fill up the tank and then look down there and all my gas was pouring out lmao. So check for leaks when you fill up next time.

Same here, although the leak was on the tank itself from rust. I was getting crappy mileage and could smell fuel after driving the car. Take a look around down there.

Check your timing and make sure it's not on the low side?

And over what mileage range is this 250 or so miles? City or highway?

check your timing. i average 36mpg city at 19* timing and it drops down to 28-29 mpg when i have my timing set to 10*.

Also check your alignmenT! make sure your toe is set to 0

your o2 sensor is working properly?

Alternator Not Charging, Battery Is Weak On Start Up,o2 Sensor, Exhaust Leak Near Header Secondary

These are going to cause more than just bad mileage. You'd see a bunch more symptoms and horrible performance with these issues.

1st 2..lights flashing, hard starting, that kinda stuff.

could be the injector gaskets, vac leaks, you could follow the fuel lines and see if they are leaking anywhere

is there oil on any of the spark plugs? i know on my is300 i did valve cover gasket, new spark plugs and it helped out w/ the fuel smell problem..