Carryfast:
If you and nmm are right then transmission manufacturers like ZF and Eaton/Fuller have all been wrong over the years and boxes like the 16 speed ‘eco’ split etc would actually have been the best way to turn an economical wagon into a thirsty one and manufacturers like DAF etc etc would have only have used 9 speed transmissions at most because,in your view,making more gear shifts,using more gears,uses more fuel not saves it.
There is no if about we are right
To prove this and beat you with your own words, read on my friend, better yet, your beloved Daf gave me the ammunition with which to shoot you down
The economy model 2800, the DKSE, came with a 9spd Fuller, not a 13spd Fuller or a 16spd ZF EcoSplit, but a 9spd Fuller
The new economy model from Daf, the ATe comes with a direct top 12 spdAS-Tronic transmission, not a 16spd overdrive
Carryfast:
If you and nmm are right then transmission manufacturers like ZF and Eaton/Fuller have all been wrong over the years and boxes like the 16 speed ‘eco’ split etc would actually have been the best way to turn an economical wagon into a thirsty one and manufacturers like DAF etc etc would have only have used 9 speed transmissions at most because,in your view,making more gear shifts,using more gears,uses more fuel not saves it.
There is no if about we are right
To prove this and beat you with your own words, read on my friend, better yet, your beloved Daf gave me the ammunition with which to shoot you down
The economy model 2800, the DKSE, came with a 9spd Fuller, not a 13spd Fuller or a 16spd ZF EcoSplit, but a 9spd Fuller
The new economy model from Daf, the ATe comes with a direct top 12 spdAS-Tronic transmission, not a 16spd overdrive
No my ‘beloved DAF’ was fitted with the 12 speed constant mesh splitter while there were plenty of others in the range that were fitted with the 13 speed fuller and (I think ?) the 16 speed eco.While the ATI’s were certainly fitted with the 9 speed fuller probably on the basis that they thought that every driver who was given an ATI would drive it by flooring the accelerator and running it up to peak power in each gear and using just a few of it’s already too few (by comparison) gears.
But it’s no surprise to me that elsewhere you have expressed some disbelief at the fuel figures which I was getting from that old 1978 12 speed.The reason for that might have been the difference between driving it my way as opposed to ZB’s example.
But if you are right then obviously the 12 speed ZF,16 speed eco etc,and 13 speed and 18 speed fullers were all a big mistake on the part of their designers and manufacturers and should never have been fitted in most trucks.
kr79:
Trucks have 12 16 18 or however many gears so there is a gear for every occasion. 44 ton on flat motorways even at 44ton a 8 speed box would be fine. Through twisting mountainous roads you are going to need more raise the weights more again. IMO at. Standard weights a 12 speed or 13 speed will be adequate.
As the previous poster has said and nmm will probaly agree been an ex press journalist and dealing with the truck builders test staff the best way is get to cruising speed as quickly as possible and umpteen gearchanged ain’t the way to do that.
Look in Europe the swedes who run at the highest gross weights in normal operations. There two major home truck builders have used a 14 speed well 12 plus 2 crawler gears for years.
That’s exactly the reason for extra gears. When I’m driving on level ground at 60 tons with Volvo or Scania, I start at 1st high (to save clutch), skip to 3rd low, 4th high, 5th and 6th and I’m at speed limiter. Only 4 shifts needed. But when climbing uphill it’s a different story. If it’s a small hill and I know I need only split then I split but if I know that I have to shift more than split then I shift one main gear, no split, because I lose boost and speed every time I have to lift pedal from the floor.
One thing I don’t understand is why some manufacturers like Volvo and DAF tune their engines so that they drop like a stone when you go past max torque peak, makes it very hard to drive efficiently. Scania and MB have always been much more willing to rev higher.
Maybe they haven’t ‘tuned’ their engines to drop like a stone beyond the torque peak maybe it’s because the guvnors have asked for them to be governed in order to stop the situation of drivers running the thing up too far beyond that torque peak by not using enough of the gears and trying to drive it as in that example which ZB made.There’s no way that any truck can be driven efficiently by taking it past peak torque and up to anywhere near peak power on a regular basis and for that you need plenty of close gear ratios to upshift the thing at the right time without then running it too low in the rev range and losing the boost.
Let’s have a vote, shall we? The best way to get a vehicle up to speed is by using a light throttle, never exceed 1300rpm, use all 18 gears in your constant-mesh 'box and use the clutch for every change. Yes or no.
[zb]
anorak:
Let’s have a vote, shall we? The best way to get a vehicle up to speed is by using a light throttle, never exceed 1300rpm, use all 18 gears in your constant-mesh 'box and use the clutch for every change. Yes or no.
Where does using over light accelerator application and a 1,300 rev limit fit in with what I’m saying which is just short (progressive) shift the thing using the best part of the torque band and for that having more (closer) gear ratios is better than having less.Which is why that type of transmission has been specced and made for years as opposed to 6-9 speeds.
kr79:
No you will end up with arm ache but it will sound nice if you have straight pipes.
So you’ve obviously never heard a two stroke fire truck being driven (almost) the way in which ZB described but still preferably with a close ratio 13 speed box to keep it close to peak power as opposed to peak torque.
i,ll only use 3 , 4 or6 gears on the 144 when acelaiting, but not always the same . but the video and driving thru al 12 gears sounds stupid, and definitly not save fuel,and thats afact the absolute thrut and can not be woted about cheers benkku(still it was not wrong whit many gears,only how to use them right
Carryfast:
If you and nmm are right then transmission manufacturers like ZF and Eaton/Fuller have all been wrong over the years and boxes like the 16 speed ‘eco’ split etc would actually have been the best way to turn an economical wagon into a thirsty one and manufacturers like DAF etc etc would have only have used 9 speed transmissions at most because,in your view,making more gear shifts,using more gears,uses more fuel not saves it.
There is no if about we are right
To prove this and beat you with your own words, read on my friend, better yet, your beloved Daf gave me the ammunition with which to shoot you down
The economy model 2800, the DKSE, came with a 9spd Fuller, not a 13spd Fuller or a 16spd ZF EcoSplit, but a 9spd Fuller
The new economy model from Daf, the ATe comes with a direct top 12 spdAS-Tronic transmission, not a 16spd overdrive
No my ‘beloved DAF’ was fitted with the 12 speed constant mesh splitter while there were plenty of others in the range that were fitted with the 13 speed fuller and (I think ?) the 16 speed eco.While the ATI’s were certainly fitted with the 9 speed fuller probably on the basis that they thought that every driver who was given an ATI would drive it by flooring the accelerator and running it up to peak power in each gear and using just a few of it’s already too few (by comparison) gears.
But it’s no surprise to me that elsewhere you have expressed some disbelief at the fuel figures which I was getting from that old 1978 12 speed.The reason for that might have been the difference between driving it my way as opposed to ZB’s example.
But if you are right then obviously the 12 speed ZF,16 speed eco etc,and 13 speed and 18 speed fullers were all a big mistake on the part of their designers and manufacturers and should never have been fitted in most trucks.
I had a couple of 2800 ATIs with the 16 speed knockover ZF box they came complete with a blindfold for the hills
I don’t get the facisnation with 2800 Dafs myself, I’ve driven a few and they were far from special
I would’ve taken an F10 or 112 over a 2800 any day of the week, in fact I wouldn’t have swapped my Sed Ak 400 with E290 for a 2800 Daf, come to think of it, the only lorry I’ve driven that I would swap for a 2800 Daf was a…2300 Daf
The only good thing about a 2800 was the bottom bunk, the rest of it (from a driver’s point of view) was crap compared to the opposition, stupid great big flat steering wheel, silly little side windows, the windscreen was too low, a broomstick for a gearstick, they smoked like a train and had air leaks galore
Carryfast:
Where does using over light accelerator application and a 1,300 rev limit fit in with what I’m saying which is just short (progressive) shift the thing using the best part of the torque band and for that having more (closer) gear ratios is better than having less.Which is why that type of transmission has been specced and made for years as opposed to 6-9 speeds.
Carryfast:
It’s all about driving a diesel engine as it’s meant to be driven over as narrow a rev range as possible,as far below the power peak as possible while still maintaining good progress which means lots of short shifted upshifts using a close ratio box to keep road speed as high as possible while engine speed is kept as low as possible… Blah blah
The best way to be fuel efficient is to get up to cruising speed as fast as possible,and that means skipping gears where appropriate.I have finished bandying words with CF,it’s no use to bang your head against a brick wall, so I’ll leave it at that.
newmercman:
I don’t get the facisnation with 2800 Dafs myself, I’ve driven a few and they were far from special
I would’ve taken an F10 or 112 over a 2800 any day of the week, in fact I wouldn’t have swapped my Sed Ak 400 with E290 for a 2800 Daf, come to think of it, the only lorry I’ve driven that I would swap for a 2800 Daf was a…2300 Daf
The only good thing about a 2800 was the bottom bunk, the rest of it (from a driver’s point of view) was crap compared to the opposition, stupid great big flat steering wheel, silly little side windows, the windscreen was too low, a broomstick for a gearstick, they smoked like a train and had air leaks galore
kr79:
No you will end up with arm ache but it will sound nice if you have straight pipes.
So you’ve obviously never heard a two stroke fire truck being driven (almost) the way in which ZB described but still preferably with a close ratio 13 speed box to keep it close to peak power as opposed to peak torque.
Tony Taylor:
The best way to be fuel efficient is to get up to cruising speed as fast as possible,and that means skipping gears where appropriate.I have finished bandying words with CF,it’s no use to bang your head against a brick wall, so I’ll leave it at that.
If I may add to this (which I believe to be correct): A vehicle which takes longer to reach its cruising speed will have to cruise faster, to record the same average speed. It will therefore use more fuel over the journey. This is irrespective of engine characteristics. Summary: if you want to waste time and fuel, accelerate at low engine speeds and use as many gearchanges as you can.
Tony Taylor:
The best way to be fuel efficient is to get up to cruising speed as fast as possible
The best way to get a loaded truck up to any speed ‘as fast as possible’ is the opposite of shortshifting at around the torque peak.It’s actually as I said upshifting at slightly below peak power.But that will still be faster in the case of using a gearbox with closer ratios than wider ones which therefore keeps the engine speed closer to it’s power peak at each upshift.But the resulting fuel figures, (regardless of wether that’s done with a wide ratio box,which is effectively what (excessive) skip shifting turns a close ratio multi speed box into) ,or a close ratio one,will be relatively horrific by comparison with using the progressive/short shifted approach at well below peak power.
What you seem to be saying is that the most economical way to drive a truck is to accelerate it up to whatever speed as fast as possible which is exactly what driving fire trucks is all about but that’s going to cost a ‘few’ extra pounds in fuel to do it and certainly isn’t the most fuel efficient way.Whereas using mainly the torque to do the job of making a truck accelerate up to speed as fuel efficiently as possible is a totally different thing.
kr79:
No you will end up with arm ache but it will sound nice if you have straight pipes.
So you’ve obviously never heard a two stroke fire truck being driven (almost) the way in which ZB described but still preferably with a close ratio 13 speed box to keep it close to peak power as opposed to peak torque.
This is trucknet not fire engine net
I was just using the comparison to show that running an engine up to peak power at each upshift is the best way to make lots of noise and burn lots of fuel.
Have you noticed that I’ve kept quiet and out of it, over the last few posts. It’s very interesting though all the different thoughts on how the most efficient rolling speed should be attained.
Reminds me of a maths lesson at school, all these figures!!
but the video and driving thru al 12 gears sounds stupid, and definitly not save fuel,and thats afact 
cheers benkku(still it was not wrong whit many gears,only how to use them right 