New Humvee?

[redpoint5]

I still wonder why the diesel Humvee only gets 8 MPG and is equipped with a 150-190 HP engine?

I could forget to take the parking brake off my diesel truck which weighs just about the same and has about the same size engine and still get better fuel economy.

Anyhow, there's several threads on the Chevy Bolt forum complaining of how wasteful the new EV Hummer is. Now to figure out how to roll electrons...

[JSH]

Originally Posted by cRiPpLe_rOoStEr

Roughly 40 years of technical development for Diesel engines playin their role. IIRC the Humvee is still fitted with a slightly modernized version of the Detroit Diesel 6.5L V8 rebranded Optimizer 6500, with the 3.4L Steyr M16 available as option.

Armored Humvees are so slow because they were never intended to be armored vehicles. The military added 7,000 pounds of armor to a 6,000 lb vehicle with a 190 HP diesel paired to a 4 speed automatic.

Yes, newer tech helps but so does matching engine output to the vehicle weight.

[JSH]

Originally Posted by redpoint5

I still wonder why the diesel Humvee only gets 8 MPG and is equipped with a 150-190 HP engine?

I could forget to take the parking brake off my diesel truck which weighs just about the same and has about the same size engine and still get better fuel economy.

Anyhow, there's several threads on the Chevy Bolt forum complaining of how wasteful the new EV Hummer is. Now to figure out how to roll electrons...

Likely a combination of 37 inch tires, low gearing, full time 4WD, portal hubs, and aerodynamics of a brick.

[cRiPpLe_rOoStEr]

Originally Posted by JSH

The military added 7,000 pounds of armor to a 6,000 lb vehicle with a 190 HP diesel paired to a 4 speed automatic.

Of course. Yet some modern 4-cyl turbodiesels below 5-litre outperform that old-school V8 fitted to the Humvee, even though they would naturally not have a performance much comparable to the Oshkosh JLTV with its Duramax-based powerplant.

Yes, newer tech helps but so does matching engine output to the vehicle weight.

Reminds me a talk I recently had with a taxi driver, regarding underpowered engines that we would often see in Brazilian vehicles as a desperate (and most often failed) attempt to increase fuel savings.

[JSH]

Originally Posted by cRiPpLe_rOoStEr

Of course. Yet some modern 4-cyl turbodiesels below 5-litre outperform that old-school V8 fitted to the Humvee, even though they would naturally not have a performance much comparable to the Oshkosh JLTV with its Duramax-based powerplant.

No doubt that 6.5L has a very low state of tune - it doesn't even have a turbo. The surprising thing is that is was an upgrade from the earlier 6.2L 165 hp V8 mated to a 3 speed automatic.

[cRiPpLe_rOoStEr]

Originally Posted by JSH

No doubt that 6.5L has a very low state of tune - it doesn't even have a turbo.

AFAIK the 195hp version fitted to the Humvee in the mid-'90s (and to earliest versions of the Hummer for the civilian market) is already turbocharged, yet its torque ratings are often pointed out as pathetic compared to a 6-cyl Cummins or the International engines fitted to the Ford F-Series around the same time.

[JSH]

Originally Posted by cRiPpLe_rOoStEr

AFAIK the 195hp version fitted to the Humvee in the mid-'90s (and to earliest versions of the Hummer for the civilian market) is already turbocharged, yet its torque ratings are often pointed out as pathetic compared to a 6-cyl Cummins or the International engines fitted to the Ford F-Series around the same time.

You recall correctly. The Detroit Diesel engines were:

6.2L NA
6.5L NA
6.5L Turbo

[redpoint5]

Yeah, my 5.9L ISB 6-cylinder diesel from 1998 puts out 235 horsepower.

Not impressed with a larger engine with more cylinders putting out much less power.

[JSH]

Originally Posted by redpoint5

Yeah, my 5.9L ISB 6-cylinder diesel from 1998 puts out 235 horsepower.

Not impressed with a larger engine with more cylinders putting out much less power.

The Humvee got a 6.5L turbo in 1994. 190 hp / 380 lb-ft was a decent spec at the time. The 1994 5.9L Cummins made 160 hp / 400 lb-ft.

AM General engines
https://www.amgeneral.com/what-we-do...ve-components/

Cummins engines.
Cummins Horsepower & Torque by Model Year

[jakobnev]

Now to figure out how to roll electrons...

A Tesla-coil exhaust maybe?