I have a 2003 Ranger XLT with the 3.0 automatic 2wd. It has just under 150,000 miles on it. I was doing decent for gas mileage. I could get at least 350 miles from a tank of gas, sometimes even close to 400 miles. (Basically low 20s.) Recently I'm struggling to get 300 miles on a tank of gas. My driving habits haven't changed. I've since changed the spark plugs and wires and that didn't seem help. The check engine light hasn't come on at all. I even ran a test and no codes are showing.
What else am I missing that could possibly cause the mpg to go down?

Thanks for any help.

 

Replace the O2 sensors they wear out after 100k miles or 12 years, ONLY sensor that wears out

 

Do they run "Winter Blend" gasoline where you are ?

https://www.caranddriver.com/news/a1...ine-explained/

 

RonD: I'll replace the O2 sensors and see if that will fix the problem.

2011Supercab: I'm not sure about if Arizona does or not. I know I didn't have any issues with the truck last winter and I drove it up to Minnesota and back getting anywhere from 20 to 24 mpgs.

 

What is a good brand of O2 sensor to get?

 

Bosch were what Ford used
Part number difference is in regards to the length of the attached cable