Anyone else noticed how when you are going downhill in an Actros MP4, it drops to neutral then when it hits 59mph it kicks down to 10th gear and puts the exhauster on?
Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.
Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
yeah i’ve noticed that they go into neutral, i think they call it eco coast or something like that.
I cannot comment about it dropping into 10th as i haven’t gone that fast in one.
jobseeker:
yeah i’ve noticed that they go into neutral, i think they call it eco coast or something like that.
I cannot comment about it dropping into 10th as i haven’t gone that fast in one.
Sure it is EcoRoll or similar, I understand the logic behind it, Volvo and the older Actros models do it.
I just can’t see that redlining to slow down is good for the engine (especially if new)
It’s a Mercedes approved way of slowing the truck. The exhaust brake is most efficient at high engine revs. The engine management won’t let the revs go over a set limit so it won’t damage itself. DPD train all their drivers to slow the truck using the exhaust brake instead of the footbrake because it’s more fuel efficient.
I set my cruise to 86kph and set the eco roll to +3mph, that way the exhaust brake cuts in at 90kph and it doesn’t drop into eco roll. I fail to see how a vehicle ticking over in what is essentially neutral can be more fuel efficient than a vehicle on the overrun where 100% of the fuel is being returned to the tank.
trubster:
Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
That is exactly how they’re supposed to work. At one previous employer, Geopost (now DPD), they put us through the Mercedes economical driving course. We were told on that course that you’re supposed to drop the gears to get the revs right up when descending and using the exhauster brake to help slow.
Exhaust brakes work better the faster the engine is turning.
Conor:
trubster:
Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
That is exactly how they’re supposed to work. At one previous employer, Geopost (now DPD), they put us through the Mercedes economical driving course. We were told on that course that you’re supposed to drop the gears to get the revs right up when descending and using the exhauster brake to help slow.
Exhaust brakes work better the faster the engine is turning.
While I agree with that, I still don’t see how Red Lining the engine is not going to damage the engine (in the longer term)
trubster:
Conor:
trubster:
Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
That is exactly how they’re supposed to work. At one previous employer, Geopost (now DPD), they put us through the Mercedes economical driving course. We were told on that course that you’re supposed to drop the gears to get the revs right up when descending and using the exhauster brake to help slow.
Exhaust brakes work better the faster the engine is turning.
While I agree with that, I still don’t see how Red Lining the engine is not going to damage the engine (in the longer term)
I’m sure Mercedes designers know what they were doing when they designed it?
i wouldnt be so confident. alot of autos are driven in manual regardless of marque.
trubster:
Anyone else noticed how when you are going downhill in an Actros MP4, it drops to neutral then when it hits 59mph it kicks down to 10th gear and puts the exhauster on?Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.
Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
It’s called using the exhaust break properly . I was like you for the past ten years odd not using them properl y(partly cuz I had a retarder on one), you’ve got to provide revs for the exhaust/engine break to work efficiently, this doesn’t use diesel although I hate over revving engines like you as long as you don’t red line him they’re fine, might use a bit more oil but will save on brake pads.
Zausters are useless unless you provide the revs.
trubster:
Conor:
trubster:
Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
That is exactly how they’re supposed to work. At one previous employer, Geopost (now DPD), they put us through the Mercedes economical driving course. We were told on that course that you’re supposed to drop the gears to get the revs right up when descending and using the exhauster brake to help slow.
Exhaust brakes work better the faster the engine is turning.
While I agree with that, I still don’t see how Red Lining the engine is not going to damage the engine (in the longer term)
You’re not in the red though, just up to the start of the red. It shouldn’t be going in the red really.
Silver_Surfer:
trubster:
Anyone else noticed how when you are going downhill in an Actros MP4, it drops to neutral then when it hits 59mph it kicks down to 10th gear and puts the exhauster on?Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.
Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
It’s called using the exhaust break properly . I was like you for the past ten years odd not using them properl y(partly cuz I had a retarder on one), you’ve got to provide revs for the exhaust/engine break to work efficiently, this doesn’t use diesel although I hate over revving engines like you as long as you don’t red line him they’re fine, might use a bit more oil but will save on brake pads.
Zausters are useless unless you provide the revs.
I agree 100%, 'Zausters are fantastic and I use them where possible - on the Renaults and Scania’s I have driven that have them (also on the Iveco’s I would rather forget 
)
I had inadvertently clicked the EB too low on the Renault once, it got near the red and came up with a picture of a boot pushing the brake pedal.
If it was me, I would use 11th gear (First Click) to hold the speed around 59-60 rather than 10th to do little more than make a lot of noise.
Silver_Surfer:
You’re not in the red though, just up to the start of the red. It shouldn’t be going in the red really.
True - It gets to a few revs off the red (As I said before, it doesn’t sound very healthy)
timmo:
It’s a Mercedes approved way of slowing the truck. The exhaust brake is most efficient at high engine revs. The engine management won’t let the revs go over a set limit so it won’t damage itself. DPD train all their drivers to slow the truck using the exhaust brake instead of the footbrake because it’s more fuel efficient.
Spot on Timmo, the continuous brake is designed to work this way it’s all to do with sucking in air to slow down and it’s all designed to work this way, engaging the continuous brake stops the fuel supply thus saving fuel.
ellies dad:
i wouldnt be so confident. alot of autos are driven in manual regardless of marque.
We have some new Euro 6’s with auto only and no manual option.
trubster:
Silver_Surfer:
You’re not in the red though, just up to the start of the red. It shouldn’t be going in the red really.True - It gets to a few revs off the red (As I said before, it doesn’t sound very healthy)
I agree.
trubster:
Silver_Surfer:
trubster:
Anyone else noticed how when you are going downhill in an Actros MP4, it drops to neutral then when it hits 59mph it kicks down to 10th gear and puts the exhauster on?Surely 10th gear which gets it just below the red line, can not be good for the engine or gearbox? plus it sounds awful.
Is it just me that thinks this or is it quite all right for it to be in 10th at 60mph?
It’s called using the exhaust break properly . I was like you for the past ten years odd not using them properl y(partly cuz I had a retarder on one), you’ve got to provide revs for the exhaust/engine break to work efficiently, this doesn’t use diesel although I hate over revving engines like you as long as you don’t red line him they’re fine, might use a bit more oil but will save on brake pads.
Zausters are useless unless you provide the revs.
I agree 100%, 'Zausters are fantastic and I use them where possible - on the Renaults and Scania’s I have driven that have them (also on the Iveco’s I would rather forget
I had inadvertently clicked the EB too low on the Renault once, it got near the red and came up with a picture of a boot pushing the brake pedal.
If it was me, I would use 11th gear (First Click) to hold the speed around 59-60 rather than 10th to do little more than make a lot of noise.
You can override it with the use of the throttle, if you use half throttle with cruise engaged while going downhill it won’t change down, or you can let it drop to 11th with the engine brake on and just depress the throttle a tiny bit and it won’t drop down to 10th. I found it out by accident the other day!
The actros’ we have do the same, and some have gone a lot faster. Dont notice it going into 10th though. The one that I drove yesterday went into 11th. I think it must be a safety feature.
lightning:
The actros’ we have do the same, and some have gone a lot faster. Dont notice it going into 10th though. The one that I drove yesterday went into 11th. I think it must be a safety feature.
Not enough weight and not a big enough hill…
Does it on a SCANIA if you use the exhaust, shoots you into the blue and DOESN’T use fuel! Nowhere near the red but not far off! 
drops a cog coming downhill, saves your fuel 