[Drummin4X4]

Hello. I have a 2012 xterra with 106k miles. I have done all the maintenance myself (oil change every 5k, all new filters, new spark plugs, etc) but my gas mileage is getting progressively worse. Typically I'll get around 80-100 miles per quarter tank on the highway. I'm only getting 60 miles now. Is there something else I'm missing as to why this is worse or just something I'll have to live with now?

Thanks!

- Ricky

 

[Fzzt]

Have you checked tire pressure lately? Cold weather they might be underinflated.
Try another gas brand, maybe winter gas?
Road raging?

 

[Drummin4X4]

Yeah, I drive pretty conservatively and on the highway most of the time. The tires are at the right pressure and being in SoCal temp doesn't change much. I'll try a higher octane but California gas isn't the greatest. I was thinking about changing the fuel filter but it and the pump are now one piece. It really confuses the heck out of me.

 

[poppaX]

What tires do you currently have on?

 

[netdobeiras]

I have to agree on crappy winter gas. mine has gone to hell, I only get 210 miles off of 16 gallons. However mines a 2001 with 121k miles.

 

[Drummin4X4]

What tires do you currently have on?[/QUOTE

I have General Grabber AT2s on. I just had them out on less than 2 weeks ago and they are the stock size of 265/70 R16

 

[BioStrom]

Have the O2 sensor checked.

 

[Grease Monkey]

What tires do you currently have on?[/QUOTE

I have General Grabber AT2s on. I just had them out on less than 2 weeks ago and they are the stock size of 265/70 R16

thats probably your issue.

 

[clifffalling]

papa always said

Always go to the last thing you did. That's probably the culprit. Oh, and never do more than one thing at a time.
Take it in for an oil change and have them check for any codes and fuel system functioning maybe.
I had the exact same issue when I bought new BFG Rugged Terrains. I ended up having to go about 3 pounds over stock inflation. That helped get me back to normal.

 

[JLBinHSV]

I have to agree on crappy winter gas. mine has gone to hell, I only get 210 miles off of 16 gallons. However mines a 2001 with 121k miles.

After changing the distributor cap, rotor, plug wires, plugs, and cleaning the MAF sensor, my 2001 is at 15.3 mpg city on new 265/75/16 TA KO2's. (The mpg is adjusted upward by 5.5% to account for the larger than stock tire circumference.) I'd sure like to get that up another 2 or 3 mpg.

PS: Also at ~ 121k btw.

PPS: Also added Seafoam to the gas tank at fill up, and ran a can thru the intake manifold via the evap port.

 

[Lee 2001 X]

Have you replaced the timing belt yet, if equipped? If it is stretching that can make a real difference.