Having got a lift with one of our drivers yesterday,his driving got me thinking is there such a thing as too much exhaust brake or having a driving style completely reliant on it.
Not a major problem in the greater scheme of things I know.just putting it out there to see what comes back.
Have a good weekend people.
No. I’ve always used the engine brake as my primary braking system. And the foot brake later in the braking phase if I’ve not quite timed it right. Obviously, in an emergency situation it’s foot brake all the way.
A mate of mine was telling me his place use Microlise. Heard of it (on here) but have no experience. He reckons his company like to restrict engine revs to 1500rpm even under engine braking as it supposedly saves fuel. Doesn’t sound right to me, could anyone shed any light on this ?
Restricting the engine to 1500rpm makes engine brakes rather useless. Wear wise engine brakes are supposed to be wear free. We keep our trucks a very long time and engine braking is used extensively. If they were so bad then why would manufacturers spend so much time and money developing them if it were cheaper to replace the brake pads and discs like a tart changes a durex.
Good drivers use the footbrake as little as possible, anticipation and reading the road is not difficult.
Sadly as we often see trucks being driven by those who have no business behind the wheel of a truck, you don’t drive anything “on the brakes” poor operation of a heavy truck costs a fortune in tyres fuel and maintenance and is bad for the environment.
Its got the point where many operators have installed equipment to monitor driver performance, sad really when drivers have to have their hand held for even the most simplest of tasks which were once routine.
Terry T:
No. I’ve always used the engine brake as my primary braking system. And the foot brake later in the braking phase if I’ve not quite timed it right. Obviously, in an emergency situation it’s foot brake all the way.A mate of mine was telling me his place use Microlise. Heard of it (on here) but have no experience. He reckons his company like to restrict engine revs to 1500rpm even under engine braking as it supposedly saves fuel. Doesn’t sound right to me, could anyone shed any light on this ?
Restricting the engine to 1500rpm makes engine brakes rather useless. Wear wise engine brakes are supposed to be wear free. We keep our trucks a very long time and engine braking is used extensively. If they were so bad then why would manufacturers spend so much time and money developing them if it were cheaper to replace the brake pads and discs like a tart changes a durex.
I believe you’re friend is referring to Fleetboard, Microlise which does have telematics features is primarily a tracking, guidance, and paperless delivery document and messaging system.
Fleetboard measures driver performance and the parameters vary between vehicle types, the driver starts his or her shift on 100% then loses points for over revving usually over 1900 RPM (dependent on vehicle type) driving out of the green band on the rev range, idling for more then 3 minutes, harsh braking and overspeeding the trucks are not limited in the rev range but you lose points for going over 1600 RPM as this is the upper limit of the green band, the use of the exhaust brake is not restricted by going outside the green range as you are not scored down when you’re foot is off the accelerator.
Fleetboard is not a problem for around 95% of drivers the other 5% were driving incorrectly to begin with, things like leaving the truck running to “warm it up” and coupling with the engine running and pointless over revving through the gears and lots of late braking.
if your using the service brakes above 20mph you’re getting it wrong, it makes driving a little more interesting in trying to predict and time it to perfection without braking, makes for a nicer drive and all the extra concentration makes it a lot safer too.
I don’t believe it is bothered with in todays training, apparently modern brakes are good enough without them?. Someone was telling me they are often not spec’d for the weight penalty ?
Bluey Circles:
if your using the service brakes above 20mph you’re getting it wrong, it makes driving a little more interesting in trying to predict and time it to perfection without braking, makes for a nicer drive and all the extra concentration makes it a lot safer too.I don’t believe it is bothered with in todays training, apparently modern brakes are good enough without them?. Someone was telling me they are often not spec’d for the weight penalty ?
Having passed my class 1 + 2 last year I was told to use the exhaust brake as much as I wanted! They class it as good reading of the road etc
I use the exhaust brake a lot more than the brake pedal.
Ta
Rich
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He could well mean microlise.As thats what we use for driver performance.We get a fuel bonus for achieving 5 certain conditions that are used with it.
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Terry T:
A mate of mine was telling me his place use Microlise. Heard of it (on here) but have no experience. He reckons his company like to restrict engine revs to 1500rpm even under engine braking as it supposedly saves fuel. Doesn’t sound right to me, could anyone shed any light on this ?
On the overrun and not under load it makes no difference to the fuel consumption how high the engine speed is.On the old tech type engines it would have been more or less idling levels of fuelling.While modern engine management systems would be expected to have fuel shut off on the overrun and never more than idle amounts.
While exhaust brakes and any type of engine braking is effectively made useless by minimising engine speed by using a too high gear.
This is difficult to explain and easily misunderstood.
Over-reliance upon the exhaust brake or retarder will have the same effect as driving the vehicle around unladen the whole time. The friction material needs to reach the lower end of its operating temperature to be in its most effective working zone. Warm brakes will be better than cold ones. So almost coming to a halt on the auxiliary brake as a matter of habit will result in brakes which do not perform as well as intended. This will be more noticeable when the brakes are cold. In short, if the friction material does not get heat cycled then its stone cold performance suffers as will its ultimate ability as well. Habitual very light braking is not a good thing.
For level roads the 20 MPH advice seems just about right.
cav551:
This is difficult to explain and easily misunderstood.Over-reliance upon the exhaust brake or retarder will have the same effect as driving the vehicle around unladen the whole time. The friction material needs to reach the lower end of its operating temperature to be in its most effective working zone. Warm brakes will be better than cold ones. So almost coming to a halt on the auxiliary brake as a matter of habit will result in brakes which do not perform as well as intended. This will be more noticeable when the brakes are cold. In short, if the friction material does not get heat cycled then its stone cold performance suffers as will its ultimate ability as well. Habitual very light braking is not a good thing.
For level roads the 20 MPH advice seems just about right.
I had never considered normal everyday type brakes being too cold, I always thought cooler the better (obviously within reason). But a few searches and it would appear some manufacturers are saying 200c as the optimal temperature for wear (not sure how wear relates to friction). Clearly you can’t keep your brakes that warm trundling down the motorway, but yes, certainly they do need regular use esp in wet whether where a bit of heat will keep them dry.
When I did an assessment with GIST in 2001 the guy said I was using the exhaust brake too much! I thought I was just using it normally, ie as mentioned above, like anticipation of slowing traffic etc, I certainly didn’t think I was over using it.
Well we use the engine brakes extensively at my gaffe and over the years I’ve had to do some pretty extreme emergency stops both on normal roads at slow speed and on the motorway sitting on the limiter. Can’t say I’ve ever felt like I could’ve done with better brakes to be honest.
This is all very interesting to me. I’m learning the theory currently and the DVSA theory book talks about use of the retarder only in relation to going downhill as a means to avoid brake fade.
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Preferred the retarder to the exhaust brake every time …
Yep, auxilliary brake (exhaust, retarder or Jacob) is my primary brake, service brakes are for coming to rest and emergencies.
Not in the least bothered what some company trainer thinks is best on the day in question.
I have use vehicles with a retarder, and are far superior to a useless exhaust brake… The retarder is coupled to the propshaft, and is more useful for using it as a primary brake, unlike the exhauster…But as retarders are very expensive, and mostly fitted to coaches these days, unless you have a boss who cares about his brakes and renewing of them, and so the majority of trucks today ( in the west ) have exhaust brakes, and i only use them when in a low gear, and proceeding down a very steep hill. We have all seen the clever one who thinks you are stupid for going so slow, and yet overtakes at top speed, then we find him at the bottom with all the rear axles on fire…a thumbs up is often called for in that situation…for me…safety is paramount.
IronEddie:
This is all very interesting to me. I’m learning the theory currently and the DVSA theory book talks about use of the retarder only in relation to going downhill as a means to avoid brake fade.Sent from my E6653 using Tapatalk
Which is bollox.
What does it cost to use it all the time?
Nothing.
As most here, I use it as my primary means of slowing all the time and the brakes come last.
It saves on brake wear and heat and when you really do need the brakes in anger, like descending a steep hill, they will be cooler instead of already hot and so increasing the risk of brake fade and a potential acident!
It really is a no brainer.
Its abit like car drivers who drive around in ■■■■■■■ rain with side lights on, why?
It costs no more to use dipped headlights so why not use the bloody things!
My lorry has a ■■■■■■ er on the drivers seat
I use an exhaust brake for the majority of the time, no problems as it assists with driving carefully & slowing down nicely, main brakes for stopping at lights or in a hurry.
Use exhaust brake except in a Daf as they are useless unless you drop a cog if fully freighted