MikeRP wrote:
4x4ord wrote:
blofgren wrote:
Cummins12V98 wrote:
But But RAM was the safest of all with ZERO brake applications. Not really anything more important.
Also had had a good time climbing with nice cool temps and guess what the fan NEVER came on.
I totally agree.
And if it wasn't for that silly CP4 fuel pump that is now bolted on to it, it is the truck that will do it reliably for many years to come.
I can certainly see a person buying a Ram for the air suspension or because they prefer the interior of the truck and I can even understand some people liking the idea that they have a Cummins under the hood. It is even possible that the Cummins has a slightly better exhaust brake .... As far as this downhill braking test demonstrating anything I don't think the testers understood the workings of the braking systems well enough to conduct a proper test:
I posted this comment on another thread and although I realize that I could be wrong I feel confident that I have come to a proper understanding of how these braking systems work:
The TFL guys said they had the Ford EB set to auto which is the best setting on the Ford for the downhill test they were doing. However there is more to it than picking a speed to hold the load at and measuring brake applications. For instance, The maximum reverse HP an engine can create occurs at maximum exhaust back pressure and engine redline. So 35 mph was an excellent speed for the Cummins to function at. It put the transmission in a low enough gear to get high torque to the rear axle and had the engine running very close to redline .... At the 4:00 and 6:00 minute marks in the video you can see the EB gauge all of a sudden display 236 reverse HP when the engine reaches redline. I believe the gauge is displaying this value while the computer applies the wheel brakes i order to prevent the engine from over revving. You can see that while the EB gauge displays a value, the speed of the truck slows from 37 mph to 35 and then the wheel brakes are released.
If they had chosen 42 mph as the speed they wanted the truck to hold to the Ram would have had a disadvantage because the truck would have shifted to 3rd gear and the engine would have dropped to about 2400 rpm. At 2400 rpm the engine would have been producing considerably less reverse HP, third gear would have put much less torque to the rear axle and Mr. Truck would have been applying the brakes prior to the engine reaching redline.
I didn't watch the Ford downhill portion again but I suspect they tried to go 35 mph with it as well. The Problem with that is 35 mph puts the Powerstroke in 3rd gear at 2800 rpm and in order to get maximum performance out of the Powerstroke EB they would have run the truck in 3rd gear at about 3400 rpm where it would have been travelling about 42 mph. And better still they could have slowed the Ford to to get it to drop into 2nd gear and ran at 32 mph and 3500 rpm. Had the Ford been running at a higher rpm the computer would have been applying the brakes when the engine rpm reached redline. (I'm not sure what rpm the 2020 Powerstroke needs to reach before the computer applies the brakes .... my '17 redlines at 3600 but I think the 2020 might be even higher)
I think the computer applies the wheel brakes at engine red line, so the Ram computer was performing multiple wheel brake applications where as it was Mr Truck applying the Ford wheel brakes prior to engine red line.
A tester really has to understand the workings of these trucks well to perform tests that demonstrate the full potential of each truck.
What is the evidence that the Ram is using the brakes on full auto? The Ram will not only take the input from the cruise control speed but uses the exhaust brake to the max and also transmission braking w the Aisin. I have never experienced this on my Ram.
I believe it was a major achievement to go down the IKE w zero brake applications and this was understated.
Similarly I think if TFL would have used the cruise on the way up set to 55 mph, that the engine instead of loafing along at 2200 rpm would have downshifted and worked to get to redline which wouldn’t have been 55 but would have got up the hill quicker.
I’m not saying it would have beat the Ford up the hill.
This is cat and mouse w the manufacturers. I still think Ram has the advantage since this 6.7 Cummins is used in many different applications. That Cummins programmed right would have made the bill in the same time as the Ford in this winter test.”, there is no doubt t in my mind.
Question is how would they all do at 95 degrees in the summer? You have to wonder on the way down would an engine go into limp mode because of excess heat., which could be a disaster. I think we saw that on Ford’s 3.0L diesel test last year. That would be bad towing 30,000 down the hill with one of these bigger diesels.
I still think Tfl ought to run the Ram up the hill using cruise. However, another thought, what % of these truck ls will tow 30,000 lbs? Certainly for the RVers not many and any one of these trucks we’d all be proud to own. They are all fantasy trucks 10 years ago and all are amazing to watch how three manufacturers get to the near same result 3 different ways.
Peace
I guess everyone needs a different degree of "proof" to be convinced of something. For me the proof that the Ram was using wheel brakes was when Andre and Mr. Truck noticed the Cummins was holding back in 3rd gear at the top of hill. Then we heard Mr. Truck explain that the new Ram has a computer controlled exhaust brake that controls the brakes, trailer brakes and lights. Further "proof" for me was seeing the exhaust brake gauge read 240 reverse hp pop up suddenly and then just as suddenly disappear after the truck slow down a couple mph.