Sudden Poor Gas Mileage...

Yes he drove from a cold climate back to Texas. The colder weather is most likely the cause of this sudden poor gas mileage.

 

I agree. All the factors that go with driving in a cold climate contributed.

 

Well to be fair winter gas will cause mixture changes, usually too lean, and the ECU will need to adjust trims. A tank or two should clear that up. Road trips with unknown gas stations may cause issues. But mainly cold causes more issues wrt viscosity of fluids/grease and tire rolling resistance. If you've been on various car/bike boards for any length of time you'll realize it is winter just by just the spike in "WTF just happened to my gas mileage" threads.

It will be 13 years this May I've had my Taco. Go thru this every winter but I still pay attention, something may be wrong you never know. Good excuse to pop the hood, check for leaks, check tire pressures etc.

 

After a tire rotation, pressure check, fuel additive, and oil change, I got back up to my usual 20mpg on my trip back to Colorado (loaded down too!) Not sure what caused the problem in the first place, but it seems to be back to normal now.

To clear the confusion, I know gas mileage changes on the conditions, but I've driven my truck for 4 years, and I've been driving in Texas and in Colorado. What was so unusual to me is that, even when I haul two dirt bikes, two dudes, and accompanying gear in the winter I still got 17 mpg. Winter fill-ups in CO I got 20mpg. I just figured something was up, but the dust has settled! I know some people drive stock trucks and get 15mpg, but for me that was a bit unusual

 

I had this same exact issue when I was up in the Rockies a few years back. I read somewhere that I should reset the ECU so it could adjust to the elevation and that ended up fixing it.

 

RIP Bro

 

Have been following the gas milage vs temp for a while now....sound like this might be the only issue. When was the MAS cleaned?