2020 Cummins IKE pull

[ib516]

VIDEO

What do you think? (other than graphic error at 18:35 that says GMC DENALI 🙂 )

For me, the time is about what I expected as it is missing a 10 speed auto and has slightly less power than the Ford.

[4x4ord]

I did an experiment with my Ford and determined that the Ford exhaust brake will produce about 170 reverse HP at the rear wheels (at 3500 engine rpm) ... likely about 145 at the crankshaft. Without the exhaust brake turned on the engine will produce about 62 negative HP. Drag and rolling resistance at 50 mph on a typical truck and 5ver is likely equivalent to about 80 negative HP. So the total resistance on my truck and trailer with the exhaust brake working at maximum capacity is about 250 negative HP at 50 mph. My 24000 lb truck/trailer on a 7% grade needs about 225 negative HP to hold it from accelerating.

Based on what I have experienced towing in the mountains the above seems about right. It takes an 8% grade before I will see may wheel brakes applied to supplement the exhaust brake.

Edit: Cummins: you need 382 reverse HP at the rear wheels of your truck to keep your 33k lb combined unit from accelerating on a 14% grade at 35 mph.

[4x4ord]

CaLBaR wrote:

4x4ord wrote:
With the Ford the brake lights only come while the wheel brakes are applied. The Ram is probably the same.

In my owners manual it states that the brake lights come on when the exhaust brake is active letting other drivers know that you are slowing down.

Rob

That's interesting but I think it is likely wrong. On my truck the brake lights only come on when the wheel brakes are applied .... when descending a grade at night I can see the brake light reflection off my trailer and the brake lights only come on when the wheel brakes are being activated. Even without the EB turned on and without a trailer hooked up, my truck will activate the wheel brakes going down a steep hill if cruise is set and the truck is wanting to accelerate down the hill. When the computer activates the wheel brakes the brake lights illuminate.


Edit: In the video we can be sure that the EB was on while that Ram was going down the hill and we can see the brake lights were not illuminated.

[GWolfe]

IdaD wrote:

ShinerBock wrote:
And it is not a theory that Mr truck has been wrong before.

Yeah, he's consistently grabbing vests that are about three sizes too small.

That was great I did LOL at that one!

[CaLBaR]

4x4ord wrote:
With the Ford the brake lights only come while the wheel brakes are applied. The Ram is probably the same.

In my owners manual it states that the brake lights come on when the exhaust brake is active letting other drivers know that you are slowing down.

Rob

[Huntindog]

FWIW, I have always used the CC with the EB on my 2011 Chevrolet.

It works so well, I have never tried it the way they do the tests.... Obviously I am not towing 30K....More like 28-30K gross.

I "think" that they do the tests the way they as a throwback to the days when the EBs and CCs were not integreated... I "think" that is pretty much standard across the brands now?

[Cummins12V98]

Next time I tow I will experiment with cruise and "AUTO" as I have always used "FULL" EB.

[Cummins12V98]

Someone please tell me where the engine was turning 3,500RPM descending the grade???

The "SOUND" of that truck is EXACTLY what mine sounds like coming down a steep grade WITH the EB on. That is NOT just the engine, the fact is when descending grade without the EB on the engine is very quiet in comparison. That was the EB "RUMBLE".

[Cummins12V98]

My gauge goes up to 230 braking HP.

I guarantee the EB did not turn off, it simply restricted more or less as needed.

[Cummins12V98]

"Just as a reminder that the previous 2020 Ram and GM trucks Ike pull had 2 brake applications with less weight. With 30k lbs the GM had more brake applications but the Ram had less."

GrassHopper, they did NOT have cruise control set on the last test you mention. For years I have said how **** well my EB brake works when the Cruize is set, now yalol know whatz I'm talkin aboot!

I repeat i have decelerated down miles of 14% locked in second at 33k combined holding 35mph. I would say they have improved keeping the truck at the selected speed. to do what I did I was holding cruise at 30mph or so.

[4x4ord]

jaycocamprs wrote:

4x4ord wrote:
I went back and watched the 4:00 minute mark of that video. I wonder why the gauge reads up to 240 reverse horsepower a while then drops off to 0? It almost seems as though the gauge starts reading at about 37 mph and it pulls it down to 35 mph then quits displaying. Could it be that while the gauge is displaying a number the wheel brakes are being applied.

240 reverse HP would definitely be slowing the truck. 175 reverse HP at the crankshaft should be enough to hold speed on the steepest part of the hill.

At the 4:00 mark, there is a red light on just over the "D". It goes out just before the -hp drops off to zero At the 6:01 mark it also shows -240 hp of braking, but no red light over the "D". Could the red light mean service brakes are applied?

That red light is a reflection of of the speedometer needle.

[4x4ord]

With the Ford the brake lights only come while the wheel brakes are applied. The Ram is probably the same.

[FishOnOne]

ShinerBock wrote:

FishOnOne wrote:

ShinerBock wrote:

FishOnOne wrote:

ShinerBock wrote:

FishOnOne wrote:
So to summarize:

Brake Applications:
Ram: 0 (Auto Brake assisted-unproven theory by Ford fanboys)
Ford: 5
GMC: 9

Time:
Ford: 10:20
Ram: 11:32
GMC: 11:47

MPG:
Ram: 2.5 mpg
Ford: 2.4 mpg
GMC: 2.4 mpg

There, I fixed it for you.

I would still love to see how these trucks do at 80F or even 100F.

I agree with testing at 80F or 100F but I doubt the order of performance would change.

And now your ok with reporting the computer mpg when you have always reported major errors with these systems.

TFL reported the brakes were part of the braking system so if you don't like that or agree with it go debate it with them like you do the Australian.

I feel the result will be similar to last years test if it were 80F. I don't


I have stated before that I don't think the computer is accurate with a lot of stop/starts of the engine. The more start/stops are in the tank average, the more it is off based on my experiences. I have also said it is fairly accurate going from point A to B without turning off the engine.

I like to report all the data(good or bad) and let the people decide for themselves instead of only giving them part of the information because of some bias. Mr Truck has reported many inconstancies before and I doubt this would be the last. After all, he also stated the truck/trailer's brake lights were on and yet they were not. Unproven theory by a Ram fanboy

Just as a reminder that the previous 2020 Ram and GM trucks Ike pull had 2 brake applications with less weight. With 30k lbs the GM had more brake applications but the Ram had less.

Give me a brake... :W

Yeah, because they did not have it on auto like I have been saying for the past two years. Auto works better if the truck is doing the shifting. Full mode is best used if you are shifting manually which they do not do.

I think the Powerstroke will get heat soaked at 80F and would have to cut power just like it looked like it did last year.

Also,it is not an unproven theory that they the brake lights were not one. It shows it in the video when they were behind the truck. And it is not a theory that Mr truck has been wrong before.

I thought the Ram was set to automatic and the cruise control wasn't set on so the system would not apply the brakes.

The Ford wasn't heat soaked as it wasn't pulling as strong from the get go. From what I've been reading this new 2020 pulls really strong compared to the '19.

If Mr. Truck was wrong the chaser truck had plenty of opportunities to see if the brake lights were not on and they could have simply edited Mr. Truck's comment out if he was wrong. There was only very short clips of the chaser truck behind the Ram. So no I don't agree with your theory.

[jaycocamprs]

4x4ord wrote:
I went back and watched the 4:00 minute mark of that video. I wonder why the gauge reads up to 240 reverse horsepower a while then drops off to 0? It almost seems as though the gauge starts reading at about 37 mph and it pulls it down to 35 mph then quits displaying. Could it be that while the gauge is displaying a number the wheel brakes are being applied.

240 reverse HP would definitely be slowing the truck. 175 reverse HP at the crankshaft should be enough to hold speed on the steepest part of the hill.

At the 4:00 mark, there is a red light on just over the "D". It goes out just before the -hp drops off to zero At the 6:01 mark it also shows -240 hp of braking, but no red light over the "D". Could the red light mean service brakes are applied?

[4x4ord]

FishOnOne wrote:

ShinerBock wrote:

FishOnOne wrote:

ShinerBock wrote:

FishOnOne wrote:
So to summarize:

Brake Applications:
Ram: 0 (Auto Brake assisted-unproven theory by Ford fanboys)
Ford: 5
GMC: 9

Time:
Ford: 10:20
Ram: 11:32
GMC: 11:47

MPG:
Ram: 2.5 mpg
Ford: 2.4 mpg
GMC: 2.4 mpg

There, I fixed it for you.

I would still love to see how these trucks do at 80F or even 100F.

I agree with testing at 80F or 100F but I doubt the order of performance would change.

And now your ok with reporting the computer mpg when you have always reported major errors with these systems.

TFL reported the brakes were part of the braking system so if you don't like that or agree with it go debate it with them like you do the Australian.

I feel the result will be similar to last years test if it were 80F. I don't


I have stated before that I don't think the computer is accurate with a lot of stop/starts of the engine. The more start/stops are in the tank average, the more it is off based on my experiences. I have also said it is fairly accurate going from point A to B without turning off the engine.

I like to report all the data(good or bad) and let the people decide for themselves instead of only giving them part of the information because of some bias. Mr Truck has reported many inconstancies before and I doubt this would be the last. After all, he also stated the truck/trailer's brake lights were on and yet they were not. Unproven theory by a Ram fanboy

Just as a reminder that the previous 2020 Ram and GM trucks Ike pull had 2 brake applications with less weight. With 30k lbs the GM had more brake applications but the Ram had less.

Give me a brake... :W

Likely the Ram wasn't set to cruise on the first test. So it was solely utilizing the exhaust brake to hold back. I think the Ike pull you're referencing had the trucks holding 25000 lbs at 50 mph. If so the engines would have had to generate about 132 reverse HP to keep from accelerating on the steepest part of the grade. The fact the Ram required 2 brake applications on that run indicates that the Cummins exhaust brake is capable of generating something a little less than 132 reverse HP at 2900 rpm (50 mph in 3rd gear). This Ike run, 39000 lbs at 35 mph, requires somewhere close to 175 reverse HP at the crankshaft to hold 35 mph.

[IdaD]

ShinerBock wrote:
And it is not a theory that Mr truck has been wrong before.

Yeah, he's consistently grabbing vests that are about three sizes too small.