I am talking about E53. Facelift E53 models have better mileage. In fact the facelift E53 4.4i has better highway mileage than E53 3.0i. I have achieved 22+ mpg on highway in E53 4.8is.

I don't know. I did have all the computers replaced in sept. '11 and I stayed at a holiday inn express last night, thatought to count for something!

And, we all know how careful and strict the mfg'ers are simulating the EPA test method, especially lately with the hwy mpg targets they all chase. :rofl:

Fwiw, our '01 3.0 shows 20.8 on the OBC, which I have re-set only three times in ~80k miles/10 years. We do high 21s to 22+ regularly on road trips, by tank/arithmetic method, and that is with the screaming rpms at speed, in our 5 spd manual.

The VetteVert rolls along at ~30 mpg on any trip... :thumbup:

Yes, tire pressure is important. Maybe I am just more sensitive and diligent having 3 scoots to ride, (that often sit for awhile between rides), and car(s) that sit, combined with huge temp swings at our NC Mtn Joint...
GL, mD

I wonder if runflats would show a less dramatic difference.

Ghost Flame FTW... Before my truck was pulling to the right fairly heavily. Checked the pressures and sure enough needed lots of corrections to get to 32 front, 33 back. After it is like I just got alighnment! Runs smoother and steering more crisp. Amazing what a few PSI can make..