Good Sam Club Open Roads Forum: Cummins vs Hummer Towing 6,000 lbs


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Fisherman

Angus, Ontario, Canada

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Posted: 10/17/22 03:53pm

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Cummins12V98 wrote:

Grit dog wrote:

Fisherman wrote:

That's almost not believable from the Cummins. I had an '04 towing a 5k trailer and never got less that 18mpg. Something wrong with that engine.

Almost as unbelievable as getting 18mpg towing a 5klb trailer….

I agree! Lot's of inflated towing claims. A box behind you at 70 will reduce your mileage for sure.

Not inflated, I didn't tow at Kirk speed, max 60 MPH and yes 18 mpg towing the trailer, sorry if I don't launch like a rabbit and have smoke coming off the brakes 3 feet before the stop sign. Have a great day..

Fisherman

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Posted: 10/17/22 03:57pm

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RetiredRealtorRick wrote:

Grit dog wrote:

Fisherman wrote:

That's almost not believable from the Cummins. I had an '04 towing a 5k trailer and never got less that 18mpg. Something wrong with that engine.

Almost as unbelievable as getting 18mpg towing a 5klb trailer….

Somebody needs either:

1. New batteries in their calculator
2. A crash course in math skills, or
3. A reminder that honesty is always the best policy

[emoticon]

I use the calculator on the computer, I passed Math and why would I fluff the results.

Cummins12V98

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Posted: 10/17/22 03:59pm

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Fisherman wrote:

Cummins12V98 wrote:

Grit dog wrote:

Fisherman wrote:

That's almost not believable from the Cummins. I had an '04 towing a 5k trailer and never got less that 18mpg. Something wrong with that engine.

Almost as unbelievable as getting 18mpg towing a 5klb trailer….

I agree! Lot's of inflated towing claims. A box behind you at 70 will reduce your mileage for sure.

Did you use the overhead or fill each tank to the top? Was your 04 RAM CUMMINS a stick or auto?

Now you mention 60 towing the video was 70 towing. You led us to believe you also were towing 70 by not saying you were towing at 60. Details matter.

2015 RAM LongHorn 3500 Dually CrewCab 4X4 CUMMINS/AISIN RearAir 385HP/865TQ 4:10's
37,800# GCVWR "Towing Beast"

"HeavyWeight" B&W RVK3600

2016 MobileSuites 39TKSB3 highly "Elited" In the stable

2007.5 Mobile Suites 36 SB3 29,000# Combined SOLD

Turtle n Peeps

California

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Posted: 10/17/22 04:42pm

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IdaD wrote:

9.7 does seem a little low to me for that setup even going 70. Not crazy low but I'd have guessed more like 11 at those speeds. It could have been a windy day, though.

The interesting thing I've learned watching some of these videos recently is how efficient these EVs are in terms of energy use. Assuming this video is accurate, the Cummins carries 5 times the energy but can only tow roughly twice as far. I suppose even less impressive is that the Hummer needs a 3000 lb battery to carry a fifth the energy vs 31 gallons of diesel.

I went through Texas one time and I got like 9 miles/gallon when I normally got 12. I was driving into a straight headwind. I would guess it was about 20 MPH? So yes, it can make a big difference.

About the motor efficiency. Electric motors are around 80% efficient. Modern diesels are roughly 40% efficient.

A gallon of #2 has about 38kwh of energy in it. So if you have a battery with 131kwh, (a Lightning battery) you have a diesel fuel tank of about 3.5 gallons of diesel. That being said, if you remember, an electric motor is 2x as efficient as an ICDE. So you now have a fuel tank of about 7 gallons of diesel in your electric truck.

A 131kwh battery (the Lightning size) can tow about 7 gallons worth of diesel. My diesel would get about 12 MPG towing that trailer. So my diesel would tow that trailer about 84 miles before I ran out of fuel.
These little electric trucks get around 3/4 of a mile/kwh towing a small trailer.

Well would you look at that!! The lightning towed that trailer 87 miles before it ran out of juice!!!

Math works!!!

~ Too many freaks & not enough circuses ~

"Life is not tried ~ it is merely survived ~ if you're standing
outside the fire"

"The best way to get a bad law repealed is to enforce it strictly."- Abraham Lincoln

Fisherman

Angus, Ontario, Canada

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Posted: 10/17/22 05:50pm

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Cummins12V98 wrote:

Fisherman wrote:

Cummins12V98 wrote:

Grit dog wrote:

Fisherman wrote:

That's almost not believable from the Cummins. I had an '04 towing a 5k trailer and never got less that 18mpg. Something wrong with that engine.

Almost as unbelievable as getting 18mpg towing a 5klb trailer….

I agree! Lot's of inflated towing claims. A box behind you at 70 will reduce your mileage for sure.

I looked at the "Lie-o-meter" infrequently, I'd fill the tank to first click and then add one gallon(there was always that room). It was an '04.5 bought in July of 04, had the 325HP600, 6 speed stick with a 3.73 rear end. Sorry about the 60 vs 70.

RCMAN46

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Posted: 10/17/22 07:33pm

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At highway speeds pulling a barn door on mostly level roads wind resistance is the major factor.
The drag from wind is a square function. There is 36% more resistance (drag) at 70 mph than at 60 mph. Thus it will take about 36% more fuel at 70 mph than at 60 mph.