Engine braking - OK or not OK?

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roxburd

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Hi all,

Do you use engine braking in your motorhome? I find myself using it a little from time to time and I suspect it's frowned upon by HGV instructors... but I've never had any instruction so I'm curious. I'd never driven a big diesel before last month. I've done the IAM motorcycle advanced test and they have a saying - brakes to slow, gears to go. It basically means that you shouldn't use engine braking. They also advise block-changing - changing to the gear you want all in one go, rather than changing one gear at a time and declutching between. And not changing gear at all until you've finished braking. It all depends on circumstance but they are general guidance points.

I try to drive my MH at a very leisurely pace - but I'm still occasionally tempted to use a little engine braking - for example, as I'm entering a roundabout with a little more speed than I'd like to carry round and the gear I want will give some braking.

I realise this might seem a bit 'who cares' to some but I've found myself wondering and so thought I'd see what people think... I suppose the important question is this: can gentle engine braking cause any mechanical issues?? I wouldn't have thought so...

Cheers
(let the disagreements commence) :)
 
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When I learned to drive, brakes were cable operated and engine braking was essential. Of course this also involved double declutching as there was no synchroness on the gearbox.
I now drive an automatic MH but have the ability to select lower gears manually which is useful for hill descents.
 
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pappajohn said:
Engine braking on a diesel is pretty abysmal.
It's drawing the same volume of air regardless of pedal position.....off or floored.
The different being injection of fuel to make it go.
Click to expand...
As long as you dont slow the Vehicle on the clutch pedal because in doing so damage to the clutch and gearbox aint far away
 
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roxburd said:
Hi all,

Do you use engine braking in your motorhome? I find myself using it a little from time to time and I suspect it's frowned upon by HGV instructors... but I've never had any instruction so I'm curious. I'd never driven a big diesel before last month. I've done the IAM motorcycle advanced test and they have a saying - brakes to slow, gears to go. It basically means that you shouldn't use engine braking. They also advise block-changing - changing to the gear you want all in one go, rather than changing one gear at a time and declutching between. And not changing gear at all until you've finished braking. It all depends on circumstance but they are general guidance points.

I try to drive my MH at a very leisurely pace - but I'm still occasionally tempted to use a little engine braking - for example, as I'm entering a roundabout with a little more speed than I'd like to carry round and the gear I want will give some braking.

I realise this might seem a bit 'who cares' to some but I've found myself wondering and so thought I'd see what people think... I suppose the important question is this: can gentle engine braking cause any mechanical issues?? I wouldn't have thought so...

Cheers
(let the disagreements commence) :)
Click to expand...
I’m a retired motorcycle paramedic, who at the time was one of the early ones. The only option available to ambulance services at the time was to ask the police to train us, and at that time the only courses available were advanced. I don’t know what bike you ride but if I tried to change from 5th/6th to 2nd on a BMW all in one go the gearbox would give up very rapidly. Engine breaking on a boxer twin is phenomenal and apart from motorists not looking for a motorcycle on blues and two’s brakes are used sparingly.

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L' Hobo said:
I think what you are describing there is not the Jake brake but the Telma retarder.
We used to have them on the coaches with a lever near the steering wheel so one could use more or less depending on the severity of the hill.
I found them invaluable when doing the Ski trips as the wheels never locked up because the retardation was achieved by the use of electromagnetics on a disc fitted to the prop shaft.

I might be wrong? 🤔
Click to expand...
No it’s an engine brake, no Telma on this van, they don’t fit to the bigger trucks. Had one on my first Morelo which was 7.5t. Definitely an engine brake.
 
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stewartwebr said:
No it’s an engine brake, no Telma on this van, they don’t fit to the bigger trucks. Had one on my first Morelo which was 7.5t. Definitely an engine brake.
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Interesting, I wonder how all the emission controls, recirculations etc, handles that? 🤔
 
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Pausim said:
The result was the car spun through 180 degrees and slid sideways into a service road in front of some shops. It came to rest very neatly parked alongside the kerb facing back towards the slip road entrance.
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Sounds like a clip from a stunt driver's TV ad.
 
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Yesterday, travelling through Devon in our Fiat 180hp, 9 speed auto PVC, we were in a queue on a hill and when I let off the brakes with little or no accelerator, the gearbox stayed in 2nd and revved to around 4,000 revs to arrest the speed. It stayed revving high when I applied a little brake and I ended up manually changing up to stop it sounding so bad!
It stays in or moves to lower gears when travelling at normal road speeds as well when I take my foot off the accelerator so Fiat gearboxes think that engine braking is ok 🤔
 
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cyberyacht said:
Sounds like a clip from a stunt driver's TV ad.
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Stunt drivers do it on purpose, I was completely out of control. A couple of weeks later we had another fall of snow at a weekend. I drove to a deserted office car park which was well hidden from view and spent an hour or more treating it as a skid pan and learning what worked when things went awry. Possibly the most valuable learning experience I ever had.

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Pausim said:
Stunt drivers do it on purpose, I was completely out of control. A couple of weeks later we had another fall of snow at a weekend. I drove to a deserted office car park which was well hidden from view and spent an hour or more treating it as a skid pan and learning what worked when things went awry. Possibly the most valuable learning experience I ever had.
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That reminds me that when we were stationed in Germany in the 60's and 70's, as soon as snow fell all car owners were given snow driving lessons (including wives if they wanted to) on the barrack square. It was invaluable and avoided a lot of costly mistakes.
 
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Captain Birdseye said:
We have a final ducato based motorhome with an automatic gearbox. Going downhill the box changes down of its own volition if I am off the throttle. I assume that it's programmed to do that.
Comments anyone?
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Ours does the same and I find it's pretty useful. You can over-ride manually if you don't want the engine braking effect.
 
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Pausim said:
Stunt drivers do it on purpose, I was completely out of control. A couple of weeks later we had another fall of snow at a weekend. I drove to a deserted office car park which was well hidden from view and spent an hour or more treating it as a skid pan and learning what worked when things went awry. Possibly the most valuable learning experience I ever had.
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Our local police station used to give lessons on their skid pan - the skills gained saved my (now ex) wife from a nasty prang. Sadly, they stopped offering that many years ago to save costs. False economy, obviously.
 
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pappajohn said:
Engine braking on a diesel is pretty abysmal.
It's drawing the same volume of air regardless of pedal position.....off or floored.
The different being injection of fuel to make it go.
Click to expand...
But all that dragged in air takes more compressing and energy when slowing things down so still very useful in the long descents
 
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roxburd said:
Our local police station used to give lessons on their skid pan - the skills gained saved my (now ex) wife from a nasty prang. Sadly, they stopped offering that many years ago to save costs. False economy, obviously.
Click to expand...
When I acquired my PSV from London Transport, they also used to give lessons to every bus driver in West London on the skid pan at Chiswick. Mine was in a double deck RT. 😄

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I've always used engine braking on every vehicle I've driven, I don't know why you would say it would be frowned upon by HGV instructors on the contrary large vehicles need this extra help when descending banks.
I have class 2 license and was taught to use the engine to slow down but at that time they were almost all manual gearboxes I don't know about nowadays the majority are automatics.
I find using the gears also gives me a good idea I'm going at the correct speed for hazards as I enter them and I'm in the correct gear when I exit.

The highways signage people advise to use engine breaking as photo.
Engine braking.jpg
 
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Barti Ddu said:
I don't get the motorcycle instructor's view at all. With a high compression petrol engine as fitted to any motorcycle, as soon as you roll off the throttle, you get a pretty big dollup of engine braking whether you want it or not. Obviously if you want to slow down any faster then you'll need to supplement this with braking too.

Last year in our Ducato motorhome I went down loads of hairpin strewn, steep Alpine passes in Germany, Austria and Slovenia. I don't see how you can descend safely without getting into a lowish gear to get some engine braking.
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My Ducato, 2.8 Automatic changes down automatically when going down hill.
 
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I taught my wife the beauty of manually overriding the auto gear box in the Landcruiser after she descended the hill to Porlock - the brakes were smoking and red hot. I was out with the fire extinguisher ready if needed.
 
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bladerunner said:
I taught my wife the beauty of manually overriding the auto gear box in the Landcruiser after she descended the hill to Porlock - the brakes were smoking and red hot. I was out with the fire extinguisher ready if needed.
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Unless you wanted to get reversed over I suspect you really pointed out how Toyota engineers had got their auto box design so badly wrong 😉

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Dazzola said:
Your motorcycle instructor couldn't be more wrong if he tried my friend.
Engine braking is very important for stability on a bike, it keeps things taught, inline and ready for the next gear change.
Using brakes only is a fools game, wet conditions -engine braking, gives you the first pointers to the grip available.
You should be listening to the engines tone during slowdown, and matching engine speed to gear position and rate of deceleration.
Kind of the same thing with a van, motorhome or car, it's a feel thing and it can make your discs and pads last much longer!
Click to expand...
O
 
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Dazzola said:
Your motorcycle instructor couldn't be more wrong if he tried my friend.
Engine braking is very important for stability on a bike, it keeps things taught, inline and ready for the next gear change.
Using brakes only is a fools game, wet conditions -engine braking, gives you the first pointers to the grip available.
You should be listening to the engines tone during slowdown, and matching engine speed to gear position and rate of deceleration.
Kind of the same thing with a van, motorhome or car, it's a feel thing and it can make your discs and pads last much longer!
Click to expand...
Absolutely agree with Dazzola, engine braking should be used almost whatever your driving on it own or in combination with the brakes I don’t agree with block changes either Some points to remember :
Diesels have far higher compression ratios than petrol .
Motorcycles have a sequential gearbox .
You need to be in the correct gear at any time ready to use power or braking at any point to cope with instantly changing situations as you drive or ride a car lorry or bike.
 
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Figaro said:
There was a guy on facebook recently that absolutely destroyed a newish clutch on an elderly Hymer using engine braking.
The clutch was completely shredded to a pile of fiberous matter and twisted metal, looked like it had been through a grater.
But I think he was using 1st gear :oops:
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Normally just use brakes ,as brake pads /shoes are cheaper than clutches and gearboxes, in saying that prolonged braking causes " brake fade" ie. Loss of brake performance, as you are either boiling the brake fluid or more likely making any resin in brake shoes or brake pads exude between those parts and brake drums or brake discs thereby creating a lubricant.
As they say in church," Here endith the first lesson" 😀
 
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Tony50 said:
Normally just use brakes ,as brake pads /shoes are cheaper than clutches and gearboxes, in saying that prolonged braking causes " brake fade" ie. Loss of brake performance, as you are either boiling the brake fluid or more likely making any resin in brake shoes or brake pads exude between those parts and brake drums or brake discs thereby creating a lubricant.
As they say in church," Here endith the first lesson" 😀
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Plenty of lubricant in my underwear when when we got the on screen " check brake fluid", as we descended the Massif Central to the Tarn Gorge a couple of years ago.:eek:
Mike.
 
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As with anything, there are degrees of application.
When I come off a motorway slip road, I change down from 5th to 4th to help me slow down.
But I don't change down to 1st for obvious reasons.
I was sent out in a 44t wagon and drag one day that had a faulty clutch. It'll be alright they said. Just navigating a roundabout and tried to engage 3rd gear (out of 16), and it went into 1st instead. Big bang, bits of clutch all over the road.
As previously stated, you have to have sympathy for the machinery.

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Figaro said:
absolutely destroyed a newish clutch
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.
Thats MY point: engine braking is great. For eg: rolling in 3rd on a slight decline is ideal to keep within the speed limit.

I used LOADS of EB in my F.Anglia because just the brakes only was not enough to wash the speed off - so loads of revs to match shaft speeds and drop the clutch, listen to that poor old 109e redlining like a good 'un ! Great Fun, but it hammered the clutch.

if you are already in the required gear, foot off will give some EB. If you need more EB, u need a lower gear - which means using the clutch. There's the rub - is it cheaper to replace brake pads, or a clutch plate ?
_
 
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