Cummins Engines

[pete_359]

Saviem:

pete 359:

Saviem:
Evening all, good ■■■■■■■ stuff coming through! cav551, excellent post on the 220s, but the engine you refer to used by ■■■■■■■ in their marketing, was a 180, in an LV ERF, (was it F, 68 reg)? that was operated by Plants at Gnosall, Nr Stafford. Cracking engine those 180s, I always thought them more “driveable” than the 205, (but not the 220).

I do not know if “my claim to fame” is truly such, but I always wondered if I was the only person in the UK to have run a KTA 18litre in a tractor unit? Back in 94 I imported a Marmon conventional, (the rare breed from Texas). Bl… ugly thing, … but wow was she impressive! KTA,@600hp, (and like lots of these show and go trucks came with the dyno sheets)! 15speed double overdrive, and a six speed spicer behind that! No, truly I could not change through every gear, who on earth specs transmissions like this, only does it for one purpose, to achieve a set of gears that provide the optimum performance for their needs, and the fact that you end up with a myriad of unusable ratios is purely incidental! Tandem SQHDs on newway air, 90in Double Eagle, odly she ran on aluminium 20in Budds,80%, and no caps. Painted in Misted Imron, (a fading green), so many gauges that you just got worried if a needle moved! But the heart, The KTA, what can one say, just excessive in every way, just the sight of it when you tipped the bonnet, the rumble, the whistle, gears, you do`nt need gears, she had come from an Owner operator from Oklahoma, via an old friend in Kansas city, and had been contracted to Bekins. Why on earth the man specified a KTA could only be ego, and lots of it! But what a wonderful machine, and what a fantastic engine, (despite having exceeded 1000000miles, as documented). And she still lives in Italy with the proud owner who purchased her from me!

[ZB], interesting point, and often overlooked, about the way manufacturers declared their engines power outputs. Apples and Pears comes to mind! Somewhere in a filing cabinet I have an excellent guide published by Unic, (Iveco), regarding the published ratings of all engines available in the French lorry market, like for like. A very useful document, (and very well thumbed)! One thing Iveco,as an organisation excell at, clear documentation, and product comparison. But they do`nt make inline 6cylinders like what ■■■■■■■ did! Cheerio for now.

Hi saviem,
My mate rob Wilson owns this mk2 contractor,seen here in Abergavenny steam fair may2012.rob’s mk2 is powered by an American k series 18 litre ■■■■■■■ diesel.as originally fitted by scammell.an interesting spec.on the marmon that you imported.
Regards Andrew.

Evening all, hello Andrew, I did not know that Scammel fitted the K series a a straight option. That Contractor is one hell of a motor to own, I presume she has a semi auto box? Lucky man!

A lot of the later French Willeme TGs, as built by Perez et Raimond, the French Detroit importer, later had the Detroits taken out, and replaced by KTs. One such, still operated and owned by Phillipe Brame, as either a ballast locomotive, or as a 120tonne 5th wheel tractor, is powered by a KTA, with a Clark auto box. Transports Zucconi had a KTA regularly working at 300tonnes, (6x4), and Transports Scalex re engined an original Willeme TG Detroit with a KTA, 8x8 at 700tonnes plus!! Some lorries! "Our " Berliet TBO, was physically similar size to the Contractor, but never, ever the match of Louis Willemes designs!! (even when retro fitted with a KTA, surely the worlds most favoured retro fit "big hitter " engine of its time),

Yes,that Marmon was an interesting, (if little confusing), spec. Most of the US iron that I imported was ■■■■■■■ powered, (I always felt “safe” with Mr ■■■■■■■■■■ but I did bring in some CATV8s, and (a big mistake… some “green leakers”), incredible noise,and with Allison Autos, so fast as to be unbelievable), but hard to sell!!

The only "double boxes " that I imported were the Marmon, two W900s, and a Pete 362, withthe longest wheelbase I have ever seen, covered by an enormous “Naughhyde” filled double Eagle, ( a masterclass in how to waste space)!! Most were RTOO. or RTO 13, or 15speed, and the second box was universaly a Spicer 6speed. Now the 362, (more blind spots than any other vehicle ever), had a 10speed Spicer, with a 6speed Spicer behind, and was actually the nicest one to drive of the lot!!! She found a home in sunny Spain, (and what an enjoyable “delivery drive” that was)!!

But you know when we look back, the biggest break through for ■■■■■■■ was the “Big Cam E290”, hi torque rise 14litre. But what consternation that engine caused in the UK market. It would not fit most chassis! Foden, ERF, had to totally redesign their front axle to take the physically larger, (heavier), engine. The only UK assembler that could accomodate the E290, was Seddon Atkinson.

But the physical dimensions were not the only problem…no one had an axle “tall enough” to accomodate 60mph @1700rpm!! Only the US manufacturers!!!( as an aside , was this the catalyst that turned Foden towards propriotory components, axles, gearboxes, et al)■■ Exactly the same situation pertained with clutches, and their torque capacity!! Could it be said that the E290 was the catalyst for US inspired drivelines in UK assembled, (manufactured) lorries■■? A point to ponder upon, and I shall ponder with the aid of several large glasses of Bollinger, Bon Nuit, mes braves, Cheerio for now.

hi saviem,
to be honest,i wasn’t aware of the k series fitted in contractor’s,which some might say,shows how little i know .i am sure rob told me she had an allison box.i take your point about the double eagle and it’s wasted space,when i imported my 359 i was astonished at the strange sleeper layout.back to the title of this thread,i also totally agree with you about the e290,i was only a kid at the time,but they really were revolutionary back then.i am pretty sure? that one of the first transcontinental’s sold in south wales had a k series ■■■■■■■ in her.there’s a picture in the book about them,glyn s. john transport ran her,an n reg. i think?keep up the info. and memories saviem,i know i’m not the only one that shares your opinions .
regards andrew.

[saviem]

Hello Andrew,… I suddenly feel old!!! Im past my sell by date, E290s are still modern to me! Good job we both like American iron, It ageless, Cheerio for now.

[carryfast]

Saviem:
A lot of the later French Willeme TGs, as built by Perez et Raimond, the French Detroit importer, later had the Detroits taken out, and replaced by KTs. One such, still operated and owned by Phillipe Brame, as either a ballast locomotive, or as a 120tonne 5th wheel tractor, is powered by a KTA, with a Clark auto box. Transports Zucconi had a KTA regularly working at 300tonnes, (6x4), and Transports Scalex re engined an original Willeme TG Detroit with a KTA, 8x8 at 700tonnes plus!! Some lorries! "Our " Berliet TBO, was physically similar size to the Contractor, but never, ever the match of Louis Willemes designs!! (even when retro fitted with a KTA, surely the worlds most favoured retro fit "big hitter " engine of its time),

Yes,that Marmon was an interesting, (if little confusing), spec. Most of the US iron that I imported was ■■■■■■■ powered, (I always felt “safe” with Mr ■■■■■■■■■■ but I did bring in some CATV8s, and (a big mistake… some “green leakers”), incredible noise,and with Allison Autos, so fast as to be unbelievable), but hard to sell!!

Blimey if you think that a Detroit was quick driving through an Allison boat anchor. You’d probably have lost at least 30% more power at the wheels as it would have done with a conventional clutch and gearbox like a fuller in it.That might explain some of the reason why they were hard to sell.

As for Willeme’s having their Detroits changed for KT’s.Even in non turbo form the V16 could make over 600 hp at around 2000 rpm with the right injector options and it would have been a lot easier and cheaper to modify them to turbocharged spec,to put them on a like with like footing with the ■■■■■■■■■■■■ go to all the trouble and expense of putting a KT into them.

forum-auto.com/automobile-pr … m#t1777289

The same applies in the case of FTF who seem to have only used the 12V71 in non turbocharged form which seem to have been more than up to the job though.In most cases the only way that ■■■■■■■ can match Detroits is on an unfair basis of comparing turbocharged ■■■■■■■ engines with non turbocharged Detroits.

janvanwees.nl/FTF/FTF.html

[zb_anorak]

Carryfast:
Blimey if you think that a Detroit was quick driving through an Allison boat anchor. You’d probably have lost at least 30% more power at the wheels as it would have done with a conventional clutch and gearbox like a fuller in it.That might explain some of the reason why they were hard to sell.

More BS. Torque converter automatic 'boxes are nowhere near as bad as you say.
allisontransmission.com/serv … 5704EN.pdf

Regarding the DD vs. ■■■■■■■ argument, the only advantage of the 2 stroke engine, for a given power output, is smaller size and weight (and therefore cost). Not much of a selling point on a ballasted tractor!

[carryfast]

[zb]
anorak:

Carryfast:
Blimey if you think that a Detroit was quick driving through an Allison boat anchor. You’d probably have lost at least 30% more power at the wheels as it would have done with a conventional clutch and gearbox like a fuller in it.That might explain some of the reason why they were hard to sell.

More BS. Torque converter automatic 'boxes are nowhere near as bad as you say.
allisontransmission.com/serv … 5704EN.pdf

Regarding the DD vs. ■■■■■■■ argument, the only advantage of the 2 stroke engine, for a given power output, is smaller size and weight (and therefore cost). Not much of a selling point on a ballasted tractor!

Firstly we’re talking about ‘were’ as bad maybe not ‘are’ as bad today with all the current developments.However the issue of any (arguable) shifting time losses,for a decent constant mesh manual box,v a torque converter auto,not being more than made up for,in power loss advantages of conventional mechanicl trans v torque converter,seems more like bs that anything which I’ve put.

I notice that none of those Allison figures actually included any chassis dyno figures (at the wheels) of an equivalent engine spec running with mechanical trans v auto.

However if a torque converter type transmission is supposed to be so good then there’s a lot of premium truck and car transmission designers who’ve got it wrong by going for the automated manual idea instead of the torque converter one.Usually torque converter autos are just used where their advantages outweigh their disadvantages and in general those ‘advantages’ have never included superior fuel economy and not losing loads of power between the engine and the wheels.

On the subject of chucking out a V16 Detroit in favour of a KT on a Willeme heavy haulage wagon,assuming that you’ve admitted that the advantage of the Detroit is better specific outputs,then what was the advantage of the KT ,with the arguable exception of better fuel consumption which would probably have been more a reflection of the non turbocharged spec of the Detroit v the turbocharged ■■■■■■■ in this case .You’ve actually missed the opposite advantage of not only a smaller size for a given power output but a bigger power output,at lower engine speed,for a given size which often gets overlooked.
By the Brits.

[v8lenny]

Allison equipped trucks have always accelerated better than any manual or automated manual trucks, espacially turbocharged because you don’t lose boost between shifts. They are worse when cruising and climbing hills because of higher transmission losses but in very heavy haul work they are again better when climbing because it’s impossible to shift gears with manual without loosing all the speed when you have 250 tons and 20+ axles or something behind you. Allison is also very heavy and expensive which is the main reason they are not used more these days.

K ■■■■■■■ is 19 litres, not 18 litres, and not very fuel efficient at light work because of PT fuel system and because of displacement, it is pumping lot of air just for nothing when the power is not needed. Detroit design was from 30s so they were not perfect either, modern 2 stroke would be quite interesting but customers would be too afraid (stupid) to try them, that’s why they are not used any more.

[sammyopisite]

I never drove a mark 2 contractor but I did drive the mark 1 ( 6x4 ) on quite a few occasions and this had a 380 turbo charged ■■■■■■■ which was rated at 240 tons and 300 tons on site work was not unusual these had a self changing gears 8 speed semi automatic gear box and a floor mounted spitter giving 16 speeds as well as a torque converter which was necessary at these weights as the gearing was a lot more important than horsepower when operating at these weights ( as the little gardner in the old 100 tonner proved ). The 250 ■■■■■■■ in the junior contractor which was rated at 125 ton was also a very good tool and I cannot recall any engine failures in either again the same gear box was fitted. The contractors replaced the super constructors ( 6x6 ) which were fitted with an Albion engine ( the same gear box 8 speed and no splitter ) but they had quite a lot of engine problems mostly porous liners. I also drove a MAN V10 rated at 150 tons which only had a 5 or 6 speed box ( column change ) and a torque converter which was well on top of the job which it was required to do.

cheers Johnnie

[carryfast]

V8Lenny:
Allison equipped trucks have always accelerated better than any manual or automated manual trucks, espacially turbocharged because you don’t lose boost between shifts. They are worse when cruising and climbing hills because of higher transmission losses

Accellerating under load is no different to climbing a hill.It’s all about how much power and torque is applied at the driving wheels.The Allison might arguably shift a bit quicker and under power but it’s usually got less,so wider,ratios.Therefore the combination of the ( fast enough ) shift times of a constant mesh box,closer ratios and lower transmission losses means a clutch type manual wins out on economy and performance over a torque converter type auto in most cases in most types of emergency or haulage trucks.

Which,as I’ve said just leaves the torque converter type auto winning out sometimes when it’s advantages outweigh it’s disadvantages such as in the case of specialist heavy haulage applications etc or in cases and/or where the truck is more often likely to be driven by licence holders than drivers.

Forget the engine in this case it’s just posted as a comparison of transmissions and shift times and the way in which the motor has to work harder for the same effect with the Allison,although obviously there’s a lot less time needed with Detroit motors because of the fast drop in revs when they’re declutched (like a car with a lightened flywheel) unlike ■■■■■■■ etc.

youtube.com/watch?v=fKHFiqfWO5k

youtube.com/watch?v=I-cM80_qs98

[cav551]

■■■■■■■ 262 (turbocharged 220) Narrow horsepower and torque band of these fairly early engines required a multispeed transmission.

youtube.com/watch?v=ol7StdtHEMc

[carryfast]

cav551:
■■■■■■■ 262 (turbocharged 220) Narrow horsepower and torque band of these fairly early engines required a multispeed transmission.

youtube.com/watch?v=ol7StdtHEMc

The idea that any type of diesel has a ‘wide’ power band is a myth in the real world.The more gears ( within reason ) that it’s got usually the easier it will be to drive and the closer it can be kept to it’s optimum output and fuel consumption engine speeds which isn’t a very wide band in any type considering that maximum power rating rpm is more an acedemic guide to what is actually realistically available below that engine speed without destroying fuel consumption and/or long term reliability.

While the most efficient way to drive any type of engine is to not let it lug too low in the range nor rev it too high.

The problem with having less gears is that it leaves no option than to run the thing very high up in the rev range on every upshift ( ie you can’t short shift it ) so that it doesn’t bog down when it gets into the next gear up.The same issue applies climbing hills when with a wide ratio box you either get caught between gears or the thing loses too much road speed faster than the revs can drop low enough for the next gear up which just leaves the choice of running it at higher engine speed than is really needed because there’s no way that it can be upshifted fast enough.

Which is why even the so called high torque rise luggers were still more often and/or better when they were specced with a 13 speed fuller than a 9 speed one.

[saviem]

Evening all, well CF, you have gone and done it again! Upset “placid” [ZB], locked horns with V8lenny, and sammyopposite, on a subject that you patently know little about, let alone have the capacity to understand, or even comprehend.

In past posts on this site, and others, you have been advised to consider your views in the light of, (shall we say, to be polite), historical, and comparative inaccuracies.

So lets consider some facts. The spec sheet shown under Phillipe Brame`s TG does not relate to the model that he owns and operates! Like so many manufacturers of “heavy hitters”, Willeme, and later their licencee P&R, custom built their machines to an individual operators specification. Spec sheets were in the main “indicators”, of what could be achieved, and not what was actually built! For comparison refer to Scammels written offerings.

The enormous growth of France`s Nuclear Power industry, and the need to move quantities of heavy loads gave Louis Willeme the reason to develop the TG range. The ready supply of a “unified” drivetrain, in that Clark/ Detroit could be obtained as a one stop, cost effective, “specified fitment” led to their adoption as the standard specification, for the type of weight/work envisaged. (150/1000tonnes gtw, in 6x4, 8x4, and 8x8 configuration).

That in operation problems relating to the actual motive power unit, led to operators seeking to "re-power at (on average) 24months, is a matter of fact, (supported by documentation sourced from Willeme, and PRP, during my evaluation of the designs, as a potential incremetal market acquisition for Saviem ). The chosen re- power unit was universally the KTA ■■■■■■■■ As was the re-powering choice for , (our), TBO Berliet, an operators prefered choice, that caused great consternation in Vennisieux, (“mon dieu, the Americans are coming”)!!!

Your comments regarding “power loss” in automated transmissions disregard the operational factors involved in hauling large weights, “on highway”. I think it is an industry norm that a Torque converter, or fully automated transmission is preferable to anything else in this application, and certainly preferable to “dropping the box” on the roadside!! Driveability, and useability are far more important than pure, “spec sheet horsepower”

That Willeme,produced potentially the best European “heavy hitter” design is an arguable fact, that the ■■■■■■■ KTA provided the best engine option is factually correct. Clessie ■■■■■■■ rules…ok. (is that contemporary speak)■■? I will away to the Bollinger to consider that fact, Bon Nuit, mes braves, Cheerio for now.

[carryfast]

Saviem:
Evening all, well CF, you have gone and done it again! Upset “placid” [ZB], locked horns with V8lenny, and sammyopposite, on a subject that you patently know little about, let alone have the capacity to understand, or even comprehend.

In past posts on this site, and others, you have been advised to consider your views in the light of, (shall we say, to be polite), historical, and comparative inaccuracies.

So lets consider some facts. The spec sheet shown under Phillipe Brame`s TG does not relate to the model that he owns and operates! Like so many manufacturers of “heavy hitters”, Willeme, and later their licencee P&R, custom built their machines to an individual operators specification. Spec sheets were in the main “indicators”, of what could be achieved, and not what was actually built! For comparison refer to Scammels written offerings.

The enormous growth of France`s Nuclear Power industry, and the need to move quantities of heavy loads gave Louis Willeme the reason to develop the TG range. The ready supply of a “unified” drivetrain, in that Clark/ Detroit could be obtained as a one stop, cost effective, “specified fitment” led to their adoption as the standard specification, for the type of weight/work envisaged. (150/1000tonnes gtw, in 6x4, 8x4, and 8x8 configuration).

That in operation problems relating to the actual motive power unit, led to operators seeking to "re-power at (on average) 24months, is a matter of fact, (supported by documentation sourced from Willeme, and PRP, during my evaluation of the designs, as a potential incremetal market acquisition for Saviem ). The chosen re- power unit was universally the KTA ■■■■■■■■ As was the re-powering choice for , (our), TBO Berliet, an operators prefered choice, that caused great consternation in Vennisieux, (“mon dieu, the Americans are coming”)!!!

Your comments regarding “power loss” in automated transmissions disregard the operational factors involved in hauling large weights, “on highway”. I think it is an industry norm that a Torque converter, or fully automated transmission is preferable to anything else in this application, and certainly preferable to “dropping the box” on the roadside!! Driveability, and useability are far more important than pure, “spec sheet horsepower”

That Willeme,produced potentially the best European “heavy hitter” design is an arguable fact, that the ■■■■■■■ KTA provided the best engine option is factually correct. Clessie ■■■■■■■ rules…ok. (is that contemporary speak)■■? I will away to the Bollinger to consider that fact, Bon Nuit, mes braves, Cheerio for now.

So are we saying in this case that we are,or aren’t,talking about a direct comparison between the 16V71 or even the 12V71 in service v the KTA . While it’s obvious in the example which I posted that it seemed to have been changed,just as has been posted here,from originally 16V71 spec to ■■■■■■■ at some point .However whatever it was that caused the change it would be interesting to find out what and why the same issues didn’t seem to apply in the case of FTF .

As I’ve said FTF seems to show that not only is the idea of the Willeme,being the best European heavy haulage wagon,an arguable fact so is the idea that the KTA was the best power unit.Especially,just as was the case,with the comparisons in the British market,with the TM,those comparisons are usually based on much smaller capacity ( too small in the case of the TM ) non turbocharged Detroits v much larger capacity turbocharged ■■■■■■■■■■■■■ the use of the obviously more expensive Rolls CV12,using around 7 more litres of capacity,and double the amount of cylinders in the Commander,to get around the same amount of power output,seems to suggest some reason why Scammell decided on that power unit instead of the obviously cheaper KT which they already had plenty of experience of using .

Although having said,unlike the CV12 and the Detroit 16V71,both the KT and the Detroit 12V71T were used in highway applications in which case it’s just impossible to understand how the KTA even in 600 hp spec could have possibly matched it .

Although as I’ve said it’s probably ( what was at the time) the very top of the highway truck engine league with either of those two options.Although it’s probably obviously always going to be a problem for the ■■■■■■■ fans that their best shot was beaten by a much smaller capacity motor.

However in the case of torque converter type transmissions I’ve already said that heavy haulage is one those applications that suits them unlike ordinary highway weight haulage applications.

[newmercman]

Carryfast, you are firmly grasping the stick at the wrong end again

Using every gear in a multispeed transmission will not make the engine either go better, nor use less fuel Every time you break drive to shift cogs, you lose momentum, this loses you time and the lost momentum takes fuel to recover, so there goes your fuel consumption

A multispeed transmission is there so that there is a gear for any given road speed and that is all

The fact that people yanked out Detroits and replaced them with ■■■■■■■ may have something to do with the fact that they actually operated the vehicles and were not happy with the leaky green screamers, unfortunately they never had the benefit of you tube videos to teach them the error of their ways back then

As an aside, I had an ex Watneys Sed Ak 400 (UGC 844W) it had an E290 and a 6spd Allison Auto, it accelerated like no other lorry I’ve ever driven, so it wasn’t losing too many of those 290 ponies that’s for sure That’s real life experience, not figures from a spec sheet

[carryfast]

newmercman:
Carryfast, you are firmly grasping the stick at the wrong end again

Using every gear in a multispeed transmission will not make the engine either go better, nor use less fuel Every time you break drive to shift cogs, you lose momentum, this loses you time and the lost momentum takes fuel to recover, so there goes your fuel consumption

A multispeed transmission is there so that there is a gear for any given road speed and that is all

There’s a contradiction contained in all that.The latter is exactly what I said.But you’re not going to be able to use all those different gears for all those different conditions unless you’ve got them in the box to start with and then use them when you’ve got them and I’ve never known a 13 speed fuller equipped wagon,driven by someone who knows how to shift it,lose any momentum between shifts.But all those who specced a 13 speed fuller with a ■■■■■■■ must be kicking themselves now bcause they didn’t put an old torque converter type Allison in it instead.

[newmercman]

You ever thought about politics Geoffrey

I know the contradiction to which you refer, but then a CVT would be the only answer to that issue

Heavy haul is totally different to regular on highway work, torque converters are used for a reason. What about the Mercedes Unimog, that thing has a huge towing capacity from a tiny little engine, all down to the gearing muliplying the torque. For the weights that a real heavy haul lorry pulls around the clutch and gearbox would have to be enourmous to create such gearing, the torque converter does all that in one, relatively, small package

This is why manufacturers such as OAF and Titan use torque converters on their extreme heavy haul chassis, I have a feeling that the blokes that designed them have a bit of an idea of what they’re doing

[bma_finland]

i,ll think the allison from today is comperative in fuel and by that not lose any more power as other boxes,it,s about electronics .in scandinavia meny new scania and volvo are whit allison ,specialy in tippers ,even in 60tn category. only bad side is the price ,the automatics is much more expencive to build then to convert a auto gearshift to a mecanic box,cheers benkku

[kr79]

Is your car automatic Geoffrey

[v8lenny]

Carryfast:

V8Lenny:
Allison equipped trucks have always accelerated better than any manual or automated manual trucks, espacially turbocharged because you don’t lose boost between shifts. They are worse when cruising and climbing hills because of higher transmission losses

Accellerating under load is no different to climbing a hill.It’s all about how much power and torque is applied at the driving wheels.The Allison might arguably shift a bit quicker and under power but it’s usually got less,so wider,ratios.Therefore the combination of the ( fast enough ) shift times of a constant mesh box,closer ratios and lower transmission losses means a clutch type manual wins out on economy and performance over a torque converter type auto in most cases in most types of emergency or haulage trucks.

Which,as I’ve said just leaves the torque converter type auto winning out sometimes when it’s advantages outweigh it’s disadvantages such as in the case of specialist heavy haulage applications etc or in cases and/or where the truck is more often likely to be driven by licence holders than drivers.

Forget the engine in this case it’s just posted as a comparison of transmissions and shift times and the way in which the motor has to work harder for the same effect with the Allison,although obviously there’s a lot less time needed with Detroit motors because of the fast drop in revs when they’re declutched (like a car with a lightened flywheel) unlike ■■■■■■■ etc.

youtube.com/watch?v=fKHFiqfWO5k

youtube.com/watch?v=I-cM80_qs98

Finnish roadworks (Tielaitos) used Sisus with M11 and Allison and similar Sisus with Eaton 16sp synchro boxes. Those with Allison were accelerating much better. There has also been some official tests by Scania between Allison, Opticruise and manual, Allison always won. It’s all about turbocharging, with manual you loose boost every time you shift and it takes time to spool up again. That’s why you don’t use every gear of your transmission when you are trying to save fuel. Even manuals accelerate better when skipping gears, for example with 14 speed Volvo and Scania I shift only 4 times to reach limiter and I usually win the drag races in France and Spain road tolls. My fuel consumption was also one of the lowest of the fleet. I also read about some fleet in GB that had 9 and 14 speed Volvos and 9 speeds were usually most fuel efficient because not so skilled drivers couldn’t use too many gears.

[carryfast]

newmercman:
You ever thought about politics Geoffrey

I know the contradiction to which you refer, but then a CVT would be the only answer to that issue

Heavy haul is totally different to regular on highway work, torque converters are used for a reason. What about the Mercedes Unimog, that thing has a huge towing capacity from a tiny little engine, all down to the gearing muliplying the torque. For the weights that a real heavy haul lorry pulls around the clutch and gearbox would have to be enourmous to create such gearing, the torque converter does all that in one, relatively, small package

This is why manufacturers such as OAF and Titan use torque converters on their extreme heavy haul chassis, I have a feeling that the blokes that designed them have a bit of an idea of what they’re doing

For the umpteenth time I’ve already said,more than once,that the torque converter type trans wins out in a heavy haulage application.But in most other types of application it’s the opposite.

[bewick]

kr79:
Is your car automatic Geoffrey

No he has a Mini,just like Mr Bean!! Bewick.