2016 Silverado 3500 - Ike Gauntlet Pull

ShinerBock wrote:
There are also some that I think are a bit confused on how the exhaust brake works. In theory a larger displacement engine like the Cummins should have a higher back pressure psi at the same rpm than a smaller displacement engine like the Duramax and Powerstroke.

You've lost me somewhere. All 3 engines are virtually the same displacement. The Cummins has larger cylinders but fewer, so in theory it should wash, right?

TFL's method of testing really demonstrates how well these trucks drivetrains are engineered by the manufacturer.

IdaD wrote:



My exhaust brake icon is yellow in full and auto modes. The manual says I should have two colors but I don't. Both modes work fine, though.

So when you hit your exhaust brake button a second time to put it in auto mode the icon on you 7 inch dash screen still remains yellow instead of turning green? Wow, that is weird. I know the light on the button remains yellow, but the icon on the dash should turn green.

IdaD wrote:


My exhaust brake icon is yellow in full and auto modes. The manual says I should have two colors but I don't. Both modes work fine, though.

Little color blind are you? Chris

So what have we learned from all of this other than these test are not real life that an experienced driver deals with out on the highways of America.

A more real video to view would be three instructional videos on how to operate a RAM, GM or Ford exhaust brake while descending a mountain pass with a load. And yes it does take a little knowledge and input from the driver to get the most out of these systems.

Note: Do I really care if the another truck and trailer got to the top 20-30 seconds faster when I am doing a 300-350 mile day on the road????? I don't think so! Try their test on the Grape Vine on I-5 in California with it's mad crazy traffic.

Chris

ShinerBock wrote:
It performed very well both up hill and down hill.


I remember when the Ram video you came out last month I sent a email to them saying they need to do the down hill portion again since the they had the exhaust brake in full mode and not in auto mode. You can clearly see they had it in full mode since the icon was yellow and not green. I never got a response back from them which was kind of a disappointment especially when they should know better being a truck site.

For those that don't have Ram's, they have two exhaust brake modes, full(yellow icon) and auto(green icon). Now I know what you you are thinking that full mode show slow you down the most. It does, but only when you are downshifting yourself so in situations like the down hill Ike test where they don't shift manually then auto mode would work better.

In auto mode, the truck will remember what speed you let off the accelerator pedal or what speed the cruise control is set to and will vary the exhaust brake and even downshift to keep you at that speed. If you let of the accelerator pedal at 60 mph, then the truck will do whatever it takes to keep you at or near 60 mph. If you start to go too fast that the exhaust brake in 6th gear is not strong enough to slow you down then it will drop down a gear that the exhaust brake is strong enough to slow you down to the desired speed just like the Chevy did in the video. The higher the rpm and lower then gear you are in then the better the exhaust brake works. As stated in the owners manual, the auto mode is meant to keep you at a certain speed.

In full mode like they had in the Ram video the truck will not downshift to keep you at a certain speed like auto mode will. All it does is activate the exhaust brake when you let off the accelerator (if the rpms are high enough and the torque converter is locked) and you will remain in 6th gear at 60 mph which is the gear that the exhaust brake is the weakest. Full mode is mainly for aiding you in slowing down since the transmission will automatically downshift as you come to a stop making the exhaust brake even stronger with each downshift. It is also good for those who like to manually downshift to a gear that the exhaust brake is strong enough to slow them down to the desired speed. It is NOT best for keeping speed (cruise control or not) going down a mountain like TFL did down the Ike.

My exhaust brake icon is yellow in full and auto modes. The manual says I should have two colors but I don't. Both modes work fine, though.

My experience with our 2015 gmc is as you tap the brake the EB becomes more aggressive especially in tow haul.I usually just put it on cruise control decending and keep dropping it down as required.My gross wt is 23500 ,using trailer brakes going down hill is a rare event.

Bionic Man wrote:

Since we have already taken it off topic............

It is actually not off topic in my opinion since the OP discusses the performance of the Ram's exhaust brake in the very first post, and has brought it up multiple times since then. Also, the brake in full mode will slow you down and downshift IF the exhaust brake is strong enough to do so. If the exhaust brake is not strong enough to slow the truck down in 6th gear in full mode, it will not downshift to slow you down unless you manually do so. If the exhaust brake is strong enough to slow you down in 6th, then it will eventually slow you down enough to force a downshift.

There are also some that I think are a bit confused on how the exhaust brake works. In theory a larger displacement engine like the Cummins should have a higher back pressure psi at the same rpm than a smaller displacement engine like the Duramax and Powerstroke. What will make them slow down the truck differently is what rpm and gear each truck is in since the exhaust brake gets stronger the higher the rpm. If the shifting strategy of the Chevy forces the truck to downshift to 4th gear while the Ram remained in 6th or 5th then of course the Chevy's exhaust brake will be stronger and slow down the truck even more. However, if they were both in the same gear and rpm then the higher displacement engine should have a stronger back pressure and therefor stronger exhaust brake. Since TFL does not manually shift, they are completely reliant on the truck to downshift to keep at a certain which is what auto mode is for, and not full mode.

ShinerBock wrote:
It performed very well both up hill and down hill.


I remember when the Ram video you came out last month I sent a email to them saying they need to do the down hill portion again since the they had the exhaust brake in full mode and not in auto mode. You can clearly see they had it in full mode since the icon was yellow and not green. I never got a response back from them which was kind of a disappointment especially when they should know better being a truck site.

For those that don't have Ram's, they have two exhaust brake modes, full(yellow icon) and auto(green icon). Now I know what you you are thinking that full mode show slow you down the most. It does, but only when you are downshifting yourself so in situations like the down hill Ike test where they don't shift manually then auto mode would work better.

In auto mode, the truck will remember what speed you let off the accelerator pedal or what speed the cruise control is set to and will vary the exhaust brake and even downshift to keep you at that speed. If you let of the accelerator pedal at 60 mph, then the truck will do whatever it takes to keep you at or near 60 mph. If you start to go too fast that the exhaust brake in 6th gear is not strong enough to slow you down then it will drop down a gear that the exhaust brake is strong enough to slow you down to the desired speed just like the Chevy did in the video. The higher the rpm and lower then gear you are in then the better the exhaust brake works. As stated in the owners manual, the auto mode is meant to keep you at a certain speed.

In full mode like they had in the Ram video the truck will not downshift to keep you at a certain speed like auto mode will. All it does is activate the exhaust brake when you let off the accelerator (if the rpms are high enough and the torque converter is locked) and you will remain in 6th gear at 60 mph which is the gear that the exhaust brake is the weakest. Full mode is mainly for aiding you in slowing down since the transmission will automatically downshift as you come to a stop making the exhaust brake even stronger with each downshift. It is also good for those who like to manually downshift to a gear that the exhaust brake is strong enough to slow them down to the desired speed. It is NOT best for keeping speed (cruise control or not) going down a mountain like TFL did down the Ike.

I test drove a new Chevy a couple weeks back and the exhaust brake is more aggressive in the Chevy than in the Ram. IMO it was not a good thing. The thing I see with the FLT tests is that they are pretty much testing for worst possible case. 99.9% of the trucks on the road will never see anything no where near the hill they test on so as far as grade braking at hwy speeds like that goes I love the way my Ram is set up. The only thing I got from this video is that if I ever encounter a grade like that I will have to hit my brakes 5 more times than the Chevy next to me.LOL At least I don't have to give it gas going down hill on the less steep grades. The D-max brake is always full on even when running around empty. The Cummins brake is variable. It acts the same loaded or not. The exhaust brake and compression brake is designed as an assist, not to stop you.

Cummins12V98 wrote:
ShinerBrock

I NEVER have used my EB in auto mode when towing. I always place my trans in the gear I would have ascended the hill in when descending and set cruise control. I have also let it do it's thing by letting off going down a grade and it does down shift. I guess I will have to give the Auto mode a try and compare it to the full on mode. I don't think it will make any difference.

You have to touch the brake pedal for the auto to work in my truck.