Cummins 1000tq vs 6.4L Hemi towing mpg

[ib516]

I found a video on YouTube of a guy who towed the same trailer over the same loop (TFL Style) with 2 different Ram trucks. One was a Power Wagon with the 6.4L Hemi and the 8 speed, and the other was a Ram 3500 SRW with the H.O. 6.7L Cummins (1000 tq). The RV was a 2020 Mallard M26 TT (~6500# dry, 8600# GVWR).

The results are pretty much what I experienced in my comparisons.

VIDEO with the Power Wagon
VIDEO with the Cummins diesel

8.4 mpg with the 6.4L Hemi (computer 8.6)
11.6 mpg with the 6.7L Cummins (computer 10.9)

I suspect a regular (non PW) Ram with the 6.4L Hemi might squeak out a little better mpg due to not being equipped with off road tires and not having the 2" lift the PW has.

[n0arp]

IdaD wrote:
and then they spend the rest of the time they own the truck trying to justify why it the diesel (better) version of their truck wasn't worth it.

My take exactly. A reply I posted in a gas vs diesel thread on another forum a few months back:

jshupe wrote:
70% of what I read in these threads just comes off as gasoline owners trying to justify to themselves their decisions not to buy diesels. There is one that is clearly superior to the other for towing, if money is not a major concern.

Yes diesels are more expensive both up front, and with maintenance costs. Fuel costs a little more per gallon. You generally don't buy RVs or cars as investments, so who cares if you never make up the cost difference. Buy what you want to drive and/or need to have. And for people who spend too much time complaining about this, diesels sure seem to hold their resale value so you get a lot of that money back if you ever sell. Reliability might have been a point to consider when the DPF/SCR first came out, and with Ford's 6.0/6.4 issues, but with modern trucks is an overblown issue.

Having had a few trucks, both gas and diesel, and several large trailers, I know what the better option is, and will drive a diesel until EVs are on the market with massive battery capacities and widespread recharge networks.

...

I've been there. Not recently, but I certainly remember how confident I was in a few of the gas engines I've owned. Funnily enough, I did the same not once, not twice, but three times regarding truck size. When I ran a midsize I said it was plenty and I did not need a full size, when I drove a half ton I said it met my needs sufficiently and it wasn't until I upgraded to a fifth wheel that I needed a 3/4T. When upgraded to another fifth I spent a couple years throwing good money after bad to make the 3/4T comfortably perform the job of a DRW. I learned my lesson many times over about using the right tools for the job, but it took a long time for me to suck it up, actually acknowledge the deficiencies, and apply that lesson when it came to trucks.

[IdaD]

ShinerBock wrote:

wowens79 wrote:
So at 112,000 miles the engine theoretically pays for itself, unless you factor in putting in that $9000 in a good mutual fund, and having it turn into $18000 over those 7-8 years.

1. That would be IF you paid cash for the truck which would be stupid because you would make more investing it especially if you get a sub 4% interest rate. Most people finance their vehicle loan so theoretically they don't have $9k to put in a mutual fund.

2. You are not counting for the fact that the diesel truck is still worth $6-7K more than the gas version at that point and you would get that much more on resale/trade-in.

3. If you look at total cost of ownership between a 6.4L and Cummins, the difference is less than a few thousands for most people over 5 years/100k miles.... in the diesels favor.

4. The diesel option in the HD is the only option that not only gradually pays for itself, but it also adds greater performance and capabilities. The $3k 4x4 option does not pay for itself or add performance. The old $1,200 for the 6.4L over the 5.7L did add performance but it did not pay for itself. In fact it cost you much more as time when on due to costlier preventive maintenance. The $11k Laramie package does not pay for itself either yet you never hear anyone talk about how long it would take for these options would have an ROI. So why do they with the diesel option?

If you look at total ownership cost on a gas truck versus the diesel equivalent, when all is said and done you've effectively got a wash. I tend to run my vehicles into the ground so in my situation I think the diesel pencils out a bit better but probably not enough to matter over that many years. That being the case, why wouldn't a person pick the one that performs substantially better? In a lot of cases I think the additional up front cost is prohibitive and some folks would rather put that towards bling, and then they spend the rest of the time they own the truck trying to justify why it the diesel (better) version of their truck wasn't worth it.

[Grit_dog]

Hammerboy wrote:


Well said. I especially like your quote about people willing to pay high dollar for a trim package but can't bring themselves to spend the money on a diesel. I've argued that for a long time but everybody's wants are different. For me its performance over luxury, I can't afford both 😉

Dan

Performance vs Luxury is like standing vs sitting to pee....
Look at who's driving the gasser next time with that in mind! Lol

[Hammerboy]

ShinerBock wrote:

wowens79 wrote:
So at 112,000 miles the engine theoretically pays for itself, unless you factor in putting in that $9000 in a good mutual fund, and having it turn into $18000 over those 7-8 years.

1. That would be IF you paid cash for the truck which would be stupid because you would make more investing it especially if you get a sub 4% interest rate. Most people finance their vehicle loan so theoretically they don't have $9k to put in a mutual fund.

2. You are not counting for the fact that the diesel truck is still worth $6-7K more than the gas version at that point and you would get that much more on resale/trade-in.

3. If you look at total cost of ownership between a 6.4L and Cummins, the difference is less than a few thousands for most people over 5 years/100k miles.... in the diesels favor.

4. The diesel option in the HD is the only option that not only gradually pays for itself, but it also adds greater performance and capabilities. The $3k 4x4 option does not pay for itself or add performance. The old $1,200 for the 6.4L over the 5.7L did add performance but it did not pay for itself. In fact it cost you much more as time when on due to costlier preventive maintenance. The $11k Laramie package does not pay for itself either yet you never hear anyone talk about how long it would take for these options would have an ROI. So why do they with the diesel option?

Well said. I especially like your quote about people willing to pay high dollar for a trim package but can't bring themselves to spend the money on a diesel. I've argued that for a long time but everybody's wants are different. For me its performance over luxury, I can't afford both 😉

Dan

[wanderingaimles]

ShinerBock wrote:

ib516 wrote:

8.4 mpg with the 6.4L Hemi (computer 8.6)
11.6 mpg with the 6.7L Cummins (computer 10.9)

With 87 octane being $2.30 where I live, that is $.26 per mile. However, if you use the recommended 89 octane in the 6.4L which currently costs $2.60 a gallon, then it is $.31 per mile. Diesel is currently at $2.70 here so that is $.23 cost per mile.

I look forward those types of comparasions next year with the new Ford 7.3 gassers. Both in trucks and motorhomes.
Will the new 10 speed tranny and the additional torque in the 7.3 give a substantial boost in economy compared to the diesels?

[ShinerBock]

wowens79 wrote:
So at 112,000 miles the engine theoretically pays for itself, unless you factor in putting in that $9000 in a good mutual fund, and having it turn into $18000 over those 7-8 years.

1. That would be IF you paid cash for the truck which would be stupid because you would make more investing it especially if you get a sub 4% interest rate. Most people finance their vehicle loan so theoretically they don't have $9k to put in a mutual fund.

2. You are not counting for the fact that the diesel truck is still worth $6-7K more than the gas version at that point and you would get that much more on resale/trade-in.

3. If you look at total cost of ownership between a 6.4L and Cummins, the difference is less than a few thousands for most people over 5 years/100k miles.... in the diesels favor.

4. The diesel option in the HD is the only option that not only gradually pays for itself, but it also adds greater performance and capabilities. The $3k 4x4 option does not pay for itself or add performance. The old $1,200 for the 6.4L over the 5.7L did add performance but it did not pay for itself. In fact it cost you much more as time when on due to costlier preventive maintenance. The $11k Laramie package does not pay for itself either yet you never hear anyone talk about how long it would take for these options would have an ROI. So why do they with the diesel option?

[wowens79]

So at 112,000 miles the engine theoretically pays for itself, unless you factor in putting in that $9000 in a good mutual fund, and having it turn into $18000 over those 7-8 years.

But you still only have half the torque. But I'm only towing about 8k lbs, so I don't need the Cummins, but it would be nice.

I think my next truck will be the 6.4 gasser, it fits my needs and budget nicely.

[FishOnOne]

ShinerBock wrote:

ib516 wrote:

8.4 mpg with the 6.4L Hemi (computer 8.6)
11.6 mpg with the 6.7L Cummins (computer 10.9)

With 89 octane being $2.30 where I live, that is $.26 per mile. However, if you use the recommended 89 octane in the 6.4L which currently costs $2.60 a gallon, then it is $.31 per mile. Diesel is currently at $2.70 here so that is $.23 cost per mile.

Oh sh!t....:B

[ShinerBock]

ib516 wrote:

8.4 mpg with the 6.4L Hemi (computer 8.6)
11.6 mpg with the 6.7L Cummins (computer 10.9)

With 87 octane being $2.30 where I live, that is $.26 per mile. However, if you use the recommended 89 octane in the 6.4L which currently costs $2.60 a gallon, then it is $.31 per mile. Diesel is currently at $2.70 here so that is $.23 cost per mile.

[ShinerBock]

ScottG wrote:
Another interesting test would be to do it with the lower output Cummins. It has higher compression and should get better mileage - but will it.

So far, it is looking like it will. But this is the only test I have seen of the new lower output Cummins with the significantly higher compression ratio.

How does the Megabuck 2019 Ram HD Mega Cab Tow? Empty and Loaded MPG Loops.

[ScottG]

Another interesting test would be to do it with the lower output Cummins. It has higher compression and should get better mileage - but will it.