If price was not a consideration, Gas or Diesel?

otrfun wrote:

pnichols wrote:

otrfun wrote:
Can I politely assume you haven't driven a Cummins with the cruise on, the exhaust brake (EB) set to auto, while driving up and down 5-7% grades with, say 13,000 lbs. behind you . . . with your feet relaxed on the floorboard? ... snip

I've never owned a diesel ... but I have driven our 12,000 lb. RV up and down 5-7% grades while leaving the cruise set on and yes, the transmission does automatically downshift to whatever gear is necessary to maintain whatever speed I have set the cruise at. If I'm not in cruise, then subsequent brake taps bring the gearing down to whatever I need or want on downgrades.

However as I mentioned earlier my rear differential is a 4:56, so that helps tremendously with hold-back from 5th gear on down.

I've driven a number of gas vehicles that auto-downshift for braking as you describe. If you were to personally drive those same grades with any of the late model Big 3 diesels (cruise on, auto EB activated) I believe you would better appreciate how different true engine braking is vs. simple downshifting.

Hmmm .... I'm tempted to say that "downhill holdback" is "downhill holdback" .... with respect to diesel exhaust braking versus gas gear braking whenever a given weight vehicle combination is able to be slowed enough or too much.

However, since the exhaust braking engine back pressure mechanism is different than the gear braking engine back pressure mechanism ... maybe exhaust braking can somehow feel different to the driver. :h

Price is no object would be an Earth Roamer. I believe these are diesel only.

pnichols wrote:

otrfun wrote:
Can I politely assume you haven't driven a Cummins with the cruise on, the exhaust brake (EB) set to auto, while driving up and down 5-7% grades with, say 13,000 lbs. behind you . . . with your feet relaxed on the floorboard? ... snip

I've never owned a diesel ... but I have driven our 12,000 lb. RV up and down 5-7% grades while leaving the cruise set on and yes, the transmission does automatically downshift to whatever gear is necessary to maintain whatever speed I have set the cruise at. If I'm not in cruise, then subsequent brake taps bring the gearing down to whatever I need or want on downgrades.

However as I mentioned earlier my rear differential is a 4:56, so that helps tremendously with hold-back from 5th gear on down.

I've driven a number of gas vehicles that auto-downshift for braking as you describe. If you were to personally drive those same grades with any of the late model Big 3 diesels (cruise on, auto EB activated) I believe you would better appreciate how different true engine braking is vs. simple downshifting.

If price were not a consideration, I would buy the most expensive truck on the lot, which would probably have a diesel engine.

Heck why would I be buying off the lot? Custom order it with EVERY option.

Order TWO in fact so when one's in the shop for whatever reason, maintenance or repair, I can drive the other.

Actually I would have THREE trucks, one from each of the big three manufacturers.

You said price was not a consideration.

towpro wrote:

otrfun wrote:
The latest model HD gas V8's are pushing ~400+ HP with new 8-10 speed trannys. Late model diesels are also pushing ~400+ HP. 400 HP means they're both capable of doing the work. But . . . that tranny on the gasser will be constantly dancing around making up for the V8's lower torque on hills---not to mention that V8 pulling 3,000 - 5,000 RPM's while that tranny dances. If the sound and feel of this dance doesn't bother you, I'd go gas. Gas means less initial cost, cheaper fuel and less maintenance. If you're not fond of the V8's little dance, go diesel. Very few, if any downshifts with the diesel. As for the exhaust brake? Priceless!

This is true. But these diesel produces 400HP at 1800-2000 RPM which is the same RPM your running down the highway at.
the gas engine produces 400HP at around 4500 rpm so it must shift, and rev anytime it needs to produce power.

and I think engine rotations per mile is directly associated with fuel economy.

If you reread my post, I believe you'll find we're saying exactly the same thing--at least in terms of driving a gas engine. However, your comment about a diesel developing 400hp at 1,800 - 2,000 rpms, is incorrect. That' the rpm they develop max torque. Max hp is much higher, around 2,800 for a Cummins. 3,000+ for the PS and Duramax.

My diesel truck sits at 2000 RPM while cruising down the highway at 65MPH

Funny, my gasoline truck only turns 1600 rpm while cruising down the highway at 65mph. As a matter of fact, it turns exactly the same RPM as my fathers diesel truck, same manufacturer, same rear end.

I actually have my father's 2016 diesel this weekend with a 5k TC on the back while I'm use to driving a 2015 6.4 Hemi with a 2.5k TC on the back, both with the same 3.73 rear end. He gets 10.5-11 mpg while I get 11.5-12.5 mpg driving at the same speed. I'm not really impressed with his acceleration, nor with the noise. Do like the exhaust brake though. So I'm getting 10% better fuel mileage and right now diesel is a 25-40% premium where I mostly drive.

Now, if I was towing heavy, I would want the diesel hands down. I actually had a 2004 Dodge 5.9 Cummins when I towed a 13k FW. But for a TC, my gasser is doing just fine at less cost per mile. Lot less to go wrong with it, no DEF requirement, and just about any dealership can work on it with comfortable. My last gas truck, 92 F350 was sold with 170k miles on the original engine and it was still going strong so 250k miles on even a gas engine today isn't a worry at all. And if my engine does go, I can probably have it changed out for about the cost of a turbo plus injectors.

Don't forget, the emissions systems is only rated for 100k miles before it needs components to be replaced, but I do know folks getting 150k out of them.

otrfun wrote:
The latest model HD gas V8's are pushing ~400+ HP with new 8-10 speed trannys. Late model diesels are also pushing ~400+ HP. 400 HP means they're both capable of doing the work. But . . . that tranny on the gasser will be constantly dancing around making up for the V8's lower torque on hills---not to mention that V8 pulling 3,000 - 5,000 RPM's while that tranny dances. If the sound and feel of this dance doesn't bother you, I'd go gas. Gas means less initial cost, cheaper fuel and less maintenance. If you're not fond of the V8's little dance, go diesel. Very few, if any downshifts with the diesel. As for the exhaust brake? Priceless!

This is true. But these diesel produces 400HP at 1800-2000 RPM which is the same RPM your running down the highway at.
the gas engine produces 400HP at around 4500 rpm so it must shift, and rev anytime it needs to produce power.

and I think engine rotations per mile is directly associated with fuel economy.

pnichols wrote:
There's a tremenduous forward-bias weight penalty to pay just to get some lower RPM quietness when trying to tow with a diesel pickup. That's probably one reason why so many diesel pickups are 4X4, because when unloaded in the rear they must really suffer from poor rear traction in slippery conditions..

When I don't drive much in slippery condition, I know my RWD dually has program that limits the diesel output on 1st and 2nd gear, or the engine torque might bend the frame.

otrfun wrote:
Can I politely assume you haven't driven a Cummins with the cruise on, the exhaust brake (EB) set to auto, while driving up and down 5-7% grades with, say 13,000 lbs. behind you . . . with your feet relaxed on the floorboard? ... snip

I've never owned a diesel ... but I have driven our 12,000 lb. RV up and down 5-7% grades while leaving the cruise set on and yes, the transmission does automatically downshift to whatever gear is necessary to maintain whatever speed I have set the cruise at. If I'm not in cruise, then subsequent brake taps bring the gearing down to whatever I need or want on downgrades.

However as I mentioned earlier my rear differential is a 4:56, so that helps tremendously with hold-back from 5th gear on down.

Just out of curiosity, if you could get the same truck with either engine for the same price would anyone still buy the gas engine?
If so, what are the reasons.

Yes I would...

While I know the benefits of the jake break (exhaust brake) having used them for countless years,there just not needed most of the time unless your going over passes with large heavy loads all the time with a pickup like with a heavy fifth wheel or trailer,but how often does that happen.

How often would I need all the torque a diesel puts out??Not very..So the HP and torque advantage is only used very occasionally and the gassers do just fine as they have for many years..

So if I use my pickup for daily use,the gas engine wins hands down..

In my case,the closest dealer for diesel problems is 100-200 miles away.If I run out of diesel for some reason,not many carry a 5 gallon jug of diesel around with them for help unlike gasoline..

If power goes out in my area only one place has fuel and it isn't diesel...If Most gas stations around here have alot of pumps but only one for diesel..If that pump goes down,no fuel but there are multiple gas pumps..

Unless it's changed,super cold weather hates diesel engines and they need a different type(#1) to run properly..

That's just a few reason why a diesel is not for everyone in every place.