Originally Posted by kayanyagio
When you made that bump, did you notice if your mpg got worse? Ours can't get any worse.
Not to answer for JFM-jr, but to add my experience. I dropped tire size as opposed to rear gear change and found that for towing it was better. The trans tended to stay in a higher gear and therefore, the towing mpg didn't change. The non towing mpg dropped by 0.5-1 mpg. This is for an equivalent change from 3.92 to 4.10. I would expect the change from 4.10 to 4.3 to be very similar.
As I mentioned in a earlier post, the low max towing and GCWR is a reflection of the 6L power, 4 speed trans and 4.1 rear gear.