What Is A Retarder And When Do You Use It?

[Dwight Hut Pizza]

So now that I've been playing this game long enough I am starting to use the more advanced functions and went to the controls to put keybinds on more things. I understood pretty much everything but then I came across retarder. Can someone please explain what this does and when I should use it please? Thanks.

[AdmiralTigerclaw]

Originally posted by The Governor:

Originally posted by Sandhill:

"The Jake brake and retarder are actually one and the same." This is simply not true.

The question was not about the dictionary definition of retarder (the hand out the window, open or grasping at straws is indeed an aerodynamic retarder by that definition) but about the definition within the highway transportation industry and specifically within ATS.
Retarders and engine brakes are two entirely different things which only share a single purpose but otherwise have nothing in common, they even work differently depending on conditions (vehicle speed, engine rpm) and really are not even functionally interchangable.

I literally linked you the definition. But you do you I guess. Me and the company I work for will continue calling it Jake and/or retarder.

I'll just keep calling them Thrust Reversers.


Wait, that's a High Bypass Turbofan.

Why does my truck have a high bypass turbofan?

[jboweruk]

Originally posted by Sandhill:

Originally posted by AyMazingATS:

American trucks for the longest time never used retarders. It was a European thing. Though still not widely used in the USA more trucks are being equipped with retarders.

Retarders have, it seems, been used quite a bit in the USA on Allison automatic transmission equipped buses and the motor homes built on bus chassis. I do not follow it closely, and was unaware that retarders were being used in any other application.
An obvious advantage of the retarder over the Jacobs type engine brake is that retarders are almost silent, where Jake brakes are more and more banned because of the noise. European standards seem to require quiet running, and I assume that is the biggest reason that retarders are common on trucks in Europe and nearly unheard of here.

In Europe we don't use 'Jake Brakes' but instead we use Exhaust Brakes. They work similarly I believe but for obvious reasons are quieter.

[zeeuwse_adonis]

https://www.youtube.com/watch?v=jaqX2mx1yhQ

[Sandhill]

There are no exhaust brakes in ATS, just engine (jake) brakes and retarders, within the game if they act differently and have different key assignments, so trying to treat them as the same will not work so well....

Originally posted by zeeuwse_adonis:

https://www.youtube.com/watch?v=jaqX2mx1yhQ

[GunBoat]

Has anyone actually used a retarder down the Grapevine (in real life)? I seriously doubt it would pass that test without the need to replace the transmission in Bakersfield. It seems to me that only the engine cooling system (engine brake) could handle the heat generated by holding back gravity with the load weight of a semi tractor trailer rolling down the grapevine.

Plus if the retarder design originated in Europe, I doubt it would be sufficient for the roads here in the USA. But I do not drive semi's, so I could be incorrect.

[zeeuwse_adonis]

https://www.youtube.com/watch?v=ehJ6z01mtxY

[jboweruk]

Just as a footnote; apparently now the newest DAF trucks here in the UK have engine brakes on them instead of exhaust brakes.

[lrrcp90]

Originally posted by jboweruk:

Originally posted by Sandhill:

Retarders have, it seems, been used quite a bit in the USA on Allison automatic transmission equipped buses and the motor homes built on bus chassis. I do not follow it closely, and was unaware that retarders were being used in any other application.
An obvious advantage of the retarder over the Jacobs type engine brake is that retarders are almost silent, where Jake brakes are more and more banned because of the noise. European standards seem to require quiet running, and I assume that is the biggest reason that retarders are common on trucks in Europe and nearly unheard of here.

In Europe we don't use 'Jake Brakes' but instead we use Exhaust Brakes. They work similarly I believe but for obvious reasons are quieter.

They are the same, muffled exhaust breaks are quite

[lrrcp90]

Originally posted by The Governor:

Originally posted by Sandhill:

#1 item that they discuss is in fact the Jake. By releasing compression in the engine, the engine itself pulls the semi back, helping it hold its speed on downhill grades, The higher the compression (the lower the gear), the more pull you receive. For example, California law says trucks may only do 35 mph down grapevine (I-5). So in my real truck I get down to 6th gear and have to run between 1st and 2nd stage jake. 1st is too weak, and I slowly gain speed, and 2nd is too strong and I slowly lose speed. If I do max jake (3rd stage) I will lose enough speed that my truck will actually downshift to 5 and eventually 4



But....

I dont have to use my service brakes. My doing so I avoid extra wear and tear. Also, as service brakes heat up, I would experience brake fade. The hotter they get, the less stopping power they have. And if I continue with this action, I can eventually smoke my brakes, which can possibly lead to brake weld or a trailer gone up in flames.

The OP's question asked what it does, and I told him. As I said before, i love the jake and I live by the Jake, Still shocked that its stated its uncommon in the state because its standard issue in all our fleet trucks.

my truck (freightliner 2020) i simply set the cruise control in decent mode and the truck manages the jake brake changing jake brake levels on the fly as needed holding the cruise speed exactly.

[lrrcp90]

Originally posted by God:

Has anyone actually used a retarder down the Grapevine (in real life)? I seriously doubt it would pass that test without the need to replace the transmission in Bakersfield. It seems to me that only the engine cooling system (engine brake) could handle the heat generated by holding back gravity with the load weight of a semi tractor trailer rolling down the grapevine.

Plus if the retarder design originated in Europe, I doubt it would be sufficient for the roads here in the USA. But I do not drive semi's, so I could be incorrect.

you have to remember it also depends on weather conditions.
anytime the road is wet you do not want to use anything that slows your drive axle because it can cause the trailer to push the tractor esp on a curve, you wind up using gears and stab breaking instead

[C0pyCatter]

Originally posted by drufus59:

use with cruise control to help stop speeding

Imo this is the best reply because in a single sentence it explains how you'd actually just it. Thanks!

[Chris]

Originally posted by GunBoat:

Has anyone actually used a retarder down the Grapevine (in real life)? I seriously doubt it would pass that test without the need to replace the transmission in Bakersfield. It seems to me that only the engine cooling system (engine brake) could handle the heat generated by holding back gravity with the load weight of a semi tractor trailer rolling down the grapevine.

Plus if the retarder design originated in Europe, I doubt it would be sufficient for the roads here in the USA. But I do not drive semi's, so I could be incorrect.

A retarder is WAY more powerful in terms of braking power. And we have the same if not steeper grades in europe with heavier trucks. so i dont know why the us is still sticking to the engine/jake brake