55,000 lb 12mpg

[GasSavers_maxc]

Taked to an ex-coworker yesterday. He is driving a new 2007 big rig. Loaded it weights 55,000 lbs. Gets 12mpg mixed driving. Hes old truck got 7 mpg. Shouldn't a Hummer get 80 to 100mpg,s?

[Matt Timion]

Originally Posted by maxc

Taked to an ex-coworker yesterday. He is driving a new 2007 big rig. Loaded it weights 55,000 lbs. Gets 12mpg mixed driving. Hes old truck got 7 mpg. Shouldn't a Hummer get 80 to 100mpg,s?

LOL

I think a lot of those big rigs have giant aero mods on them (usually a big shell on top, etc.)

That being said, something tells me the big rig is a diesel and the hummers use the bad bad gasoline.

[95metro]

Aero mods probably do a lot for the big rigs. Kenworth has an entire brochure on it:

http://www.kenworth.com/brochures/FuelEfficiency.pdf

The other big difference would probably be the powertrain. Matt, you are right about the Hummer's being gas-powered - at least the H2 and H3 models, but the big 'ol H1 is a 6.6L Duramax turbo diesel rated at 300 hp. This is mated to an Alison 5-speed automatic (read power/fuel sucking) transmission.

Big rigs can be anywhere from 300 to 600 hp diesels, but the gear boxes range from 9 to 18 speed manuals!

http://www.peterbilt.com/387Details.asp?model=model387

[Matt Timion]

Originally Posted by 95metro

Big rigs can be anywhere from 300 to 600 hp diesels, but the gear boxes range from 9 to 18 speed manuals!

http://www.peterbilt.com/387Details.asp?model=model387

Yeah, i'm certain that having an 18th helps a little

Think I can put one of those on my civic?

No? Okay.

[95metro]

Imagine the short-shifting capabilities though!

[Sludgy]

Some of these behemoths with proper gearing get much better mileage than you'd expect.

I'm WAY torqued that the smallest diesel you can get in a Ford pickup is a whopping 325 HP, when Ford offers a 200 HP diesel in their Class 4 & 5 delivery trucks. 325 HP is way too much power, the truck is pulling mayber 10% of that at highway speeds, and is not in an efficient operating spot.

The 200 HP motor would operate in a sweet spot in a pickup. But ****upord won't offer it.

[GasSavers_maxc]

This past winter there was a program on "UPN 50 local station" "Cool fuels" This guy had a full size i think Dodge diesel pickup getting 45 mpg on hiway,on bio-diesel fuel. That truck had to weigh 5000lb+. I think it was 4WD?