Looking to regear my 2003 7.3 Excursion (2wd) factory tire size... looking to get better fuel economy on the highway speeds...

Avg 16mpg city/hwy
hwy 19 mpg (under 70mph)
city 14.5mpg

Factory rear gear is 3.73 and looking to step down to 3.42 or 3.55.

Anyone swapped to a lower gear? If so, any pros/cons?

I know it will reduce pulling weight but that's not an issue as I hardly ever pull a trailer.

 

I’d look into a splitter like Gear Vendor etc, that way you get the best of all worlds. More selectable ratio options, overdrive...

 

Something to also keep in mind.
Speed and torque are related. If you move one down the other goes up, if the engine RPM goes down you will affect the torque available. The start off power may not be what you used to have , just a reminder.

 

Thanks, Haypower... I have looked into the gear vendors... it is the best option but it's going to cost around $4500 total set up and you have to either shorten the original drive shaft or get a donor... either way the ROI will take about 8 yrs to recover the cost savings in fuel with a gear vendor. This is the wifes truck and we never pull with it...