Downsized from 265/75 down to 265/70

I bought my truck used and it came with 265/75r16 KO2. I was getting around 20.8 MPGs and never got above 22mpg. With my commute and the use of the truck being on the street 95% of the time, I changed my tires to 265/70r16 and went with Kumho HT51. The truck rides like a sedan now when compared to the KO2. My daily commute gave me an average of 23.2mpg and this was while being stuck in traffic. The truck also cruises at a lower RPM and doesnt gear hunt as much when I use cruise control. I have a 2.7L and my commute encompasses going up several steep grades.

 

Probably not as much to do with the size as it is you want from an E Load all terrain tire to a much lighter and less aggressive highway tire.

 

@MoneyB86 thanks for the info! Many forum members should find this helpful when considering wheel/tire upgrades. I would agree with @cosmic65charlie in regards to weight being a factor for MPG.