Sad Effort at Hypermiling A Hummer :(

[ThePrudentNinja]

Originally Posted by oldtamiyaphile

I think you're under estimating just how bad a H1 really is. Aero is many times worse than any van, amazingly tortured underbody aero...
(vans are actually pretty good aerodynamically - a Ram Promaster has a 0.31cd - even old 70's vans were around 0.45 roughly the same as a current Jeep Wrangler), super wide (frontal area), off road tyres, constant AWD, portal axles (basically a gearbox on each wheel, auto (probably without lock up?).

Although my TJ Wrangler can beat EPA, it's not by much.

Possibly. The Hummer wasn't designed with fuel economy in mind it seems. However if I could afford a Hummer, I bet I could squeeze out more MPGs than this guy did. Maybe nothing spectacular, but better at least. The van I have is not very graceful. Coating down a hill it loses speed fast unless you keep on the gas. It only "coasts" down very very steep hills lol. The car I'm currently borrowing until I get my hands on my new car gains speed down hills. I can't say how the van and the Hummer compare, but they have some things in common for sure. Point still is I bet in the hands of just about anyone on this forum, a Hummer would get better fuel economy.

[Vman455]

According to this Edmunds article, the H1 has a drag coefficient around .70, and this site estimates frontal area at between 37.0-39.5 square feet, depending which model. With its lightest curb weight of 7847 lbs, plugging that into the calculator with Crr .015 and engine efficiency at .25, spits out 12.6 mpg at 55 mph.

[Xist]

I have plenty of experience driving military vehicles, but even though I always tried to drive cars and even school buses efficiently, all that I know about military fuel efficiency is that my fuel truck was rated at having a 300-mile range on a 150-gallon tank.

Of course, being a fuel truck, you stop, fill up the entire convoy, and continue driving.

However, having driven military vehicles, I never want anything even slightly resembling one. The HMMWV is big on the outside, but small on the inside, and I need earplugs when I struggle to maintain 55 MPH on the freeway.

I am not fond of zipper windows, either. I wonder if any Soldier has ever successfully had that fixed through a work order. I think that you just "secure" another door.