On the higway

[HummerMann]

I had to make a trip to Syracuse yesterday, so I aired up my OEM Goodrich tires to 45 psi (well below the 50 psi max redommended), took off the roof racks and set out. I kept the speed at 60 mph and drafted a few semis on the way. I increased speed a few times to keep in the semi draft from about 3 Hummer lengths behind. The display under the speedo said 24.5 gallons used when I got there, which was within .3 and the mpg display read 14.1 which was an actual 13.76 based on the nav gps mileage shown. That was my best ever! I wonder if airing up the tires and keeping it around 60 really makes that much of a difference? I normally get in the 11s on the hwy. Anyone ever get over 14 mpg?

[Adam in CO]

Yes, all of those things make a big difference. Higher tire pressure, lower speeds, less weight, less wind resistance, etc.

I have never seen 14. Maybe downhill, with a tail wind, off a cliff.

[HummerJim]

I have never seen anything other than something in the 11s on the highway,and I have my roof racks off (so it will fit in the garage). I do have a heavy foot and I keep the cruise control on 73mph on the highway. Your posting did get me to check my tire pressure and I found my left front at 30 psi, but all the others at 37 cold.

[Metallic Red]

This past weekend my wife and I went to Lake Wallenpaupack in the Pocono mountains(day trip) about 2.5hrs ride. Check Fuel Economy when we got home, and averaged 13.9 MPG, this was hand calculated not from the DIC.