Fuel mileage issue

Hey guys I have another question for you. For some reason this past full up my fuel mileage dropped from roughly around 22 mpg to about 14-15 mpg. It's an 03 prerunner with a 3.4 any ideas?

 

Could be that you drove more aggressively, poor gas, or bad 02 sensor, but there are so many reasions for it.

 

Heh, just ONE fillup?

I will say this: usually the simplest explanation is the correct one. Last time you didnt fill it up all the way.

 

The difference was in one fillup. I filled up my tank drove home and noticed right off the bat that my gauge dropped further than usual and I always reset my trip odometer when I fill up just invade something like this happens. I wasn't driving aggressive and infact I noticed after today when I had to get on it a bit it started getter gas mileage again. Now I'm think maybe a fuel filter or something. Any thoughts? I'll post what's find out just invade this happens to anyone else

 

Proper tire inflation?

 

It is now *conclusive*. You definitely need to pay more attention when filling the tank. Sometimes the handle will shut off before the tank is full. YOUR TANK WAS NOT FULL!!!!

 

I have a second gen and live in Ne, but I just completed some personal research on the local fuel. We have ethynol fuel here and using 91 octane with no ethynol outside of Omaha from shell, I can get 22.5 MPG using 89 with ethynol I get about 15 MPG. 87 without ethynol 19 MPG and 91 which dosen't say it has ethynol (which I don't believe because I am in Nebraska) still gets around 15 16 MPG. So a long story short it may simply be the quality of gas for that single tank. I was amazed to see my milage go from 22.5 MPG to 15 MPG in just one tank. The Gas station makes the difference, but I wouldn't be concerned from one tank if the poor mileage is not consistant. Time will tell.

 

Ethanol additive in the fuel will do it too

 

I don't think ethanol would kill your mileage over 30%. I think we have 10% ethanol in our gas here in California and I get around 22 on the highway in my V6 4x4.

The assertion that your tank was not completely full on the last fillup makes the most sense to me.

 

If the only thing the OP noticed was MPG, I doubt it was the fuel.

Again, we're talking about a hit of over 30% in MPG. That's almost how much of a hit I take when I tow my boat. If the fuel was that low in energy, IMHO he would have noticed a difference in the way it drove.

 

Well I have flucuated from 15.1 - 22.6 and the only difference was the fuel, so you wont really know what the issue is until you get historical data. If the problem is consistant, it may be the truck.

 

well my tank is almost done and im about to fill up again. i had poor fuel mileage the entire tank. also im positive i had a full tank from the beginning. i also noticed a lack in power. im right at the time to do an oil change and also change my air filter. im going to try to run sun fuel injector cleaner through. i just did a tune up a few months ago so i doubt its an ignition issue. im going to change the fuel filter as well and see what happens. first im gonna verify its not the gas by filling up again and see if it does it still.

 

You're filling up at different gas stations, right?