Hello all
I know engine speed varies with each truck but I’ve just bought a scania and the green band is from 1,100 to 1,500 rpm however when it’s in 12th gear and at 56 the needle is on 950rpm, will this damage anything and also every hill even when it’s empty it knocks it down to 11th so surely it’s affecting the mpg’s as well… do you know how I go about bringing the needle so it’s like at 1,100-1,200 like my other trucks?
Thanks
if thats the case its doing about 52mph, imho it need to be around 1100 rpm, but to get this you need it recalibrating and find a nice man that will get it up to 56mph
if its not a v8 it will knock down a gear up the hills as 12th is to high a gear for the 6 cyclinders, and even wit hthe higher revs it will still knock down to 11th empty up hills
If it has been like that from the factory then it has special Opticruise software for fuel economy and very fast gearing optimized for it. So dont try to change anything, except maybe speedlimiter.
Sounds like it has a really deep diff ratio. As this is a gearing issue there’s Not a lot you can do except change the diff, which would be expensive unless you have a spare knocking around. This is assuming it is actually doing 56 mph when it says so on the speedo.
Our 2013 R480 does 1200 rpm at 56mph in twelfth gear.(manual box) This might be fine for European haulage at 40t on easy motorways, but is pretty hopeless in the wild west and north of Scotland.
Apart from a feeble performance in top gear, it is far too high geared for manoeuvring with heavy loads in tight spaces.
It is, as a previous poster has said,it is a consequence of being fitted with an inappropriate final drive ratio, in my own defence, we bought it second hand and had no input in the build spec. Quite a few drivers round here, even with the V8520 engine. never engage top gear, preferring g to run their engines at around 1400rpm, and say that they see very little if any fuel penalty.
It’s the first Scania I’ve had in nearly forty years of owning trucks, and to be honest , I’m pretty underwhelmed.
You say that yours only does 950 rpm. This seems completely unfeasible, and I suspect there is a fault in either the speed limiter, which will be very obvious on the motorway, or in the rev counter itself. Ours has quite a few wee electrical idiosyncrasies , including engaging g the cruise control at random, and without any input from the driver.
Anybody out there know how to make them do more than 6.8mpg!!!
I think the op means 1950 rpm not 950 ?
no 950 id say, as mine does 1050/1100
Some scary reading here.
Manufacturers spend untold millions developing the most efficient drive train they can and drivers run a gear down from top because they know better!
And drivers moan about companies that remove the manual function from autoshift boxes!
To the OP, yours sounds wrong though, there’s high gearing and then there’s madness, if yours is really running at 950rpms at 90km/h then you have a rear axle ratio for a direct drive top gear and an overdrive gearbox.
Or more than likely a dodgy sensor or somesuch electronic wizardry that’s not behaving itself.
JSingh:
Hello allI know engine speed varies with each truck but I’ve just bought a scania and the green band is from 1,100 to 1,500 rpm however when it’s in 12th gear and at 56 the needle is on 950rpm, will this damage anything and also every hill even when it’s empty it knocks it down to 11th so surely it’s affecting the mpg’s as well… do you know how I go about bringing the needle so it’s like at 1,100-1,200 like my other trucks?
Thanks
Firstly there’s no way you want to climb inclines at the same engine speed or same gear that it’s running at 56 mph on the flat.When climbing it needs to be running at least at 1,500 rpm maybe a bit more and downshifting as required as the revs fall at not less than 1,200 rpm.In which case the downshift sounds sensible regardless.
Which leaves the question of the final drive gearing which seems all wrong for a 56 mph or even a 60 mph max environment. 
Bearing in mind that more load at lower engine speed can use more fuel than less load at a higher engine speed.Which is why the green band has a lower cut off as well as a higher one.
No, it’s meant to drive like that.
V8Lenny:
No, it’s meant to drive like that.
If it is it would take some trick fuel mapping to make it work.IE optimised fuelling to suit a gearing combination which provides the perfect match with extreme low engine speed and just enough output for very low engine load situations.But which likewise effectively just makes top gear an extreme over drive which can only be used in perfect flat light traffic running conditions to suit.Which might explain 11th then being the default gear in anything other than those perfect conditions ?.IE in anything other than extreme light load conditions it needs a downshift ?.Which seems like a liability in UK type traffic and terrain conditions or possibly even in the case of anything more than light headwinds.
Carryfast:
V8Lenny:
No, it’s meant to drive like that.If it is it would take some trick fuel mapping to make it work.IE optimised fuelling to suit a gearing combination which provides the perfect match with extreme low engine speed and just enough output for very low engine load situations.But which likewise effectively just makes top gear an extreme over drive which can only be used in perfect flat light traffic running conditions to suit.Which might explain 11th then being the default gear in anything other than those perfect conditions ?.IE in anything other than extreme light load conditions it needs a downshift ?.Which seems like a liability in UK type traffic and terrain conditions or possibly even in the case of anything more than light headwinds.
Yes almost right but fuel mapping doesnt change because of emissions. It’s only with Opticruise so that driver doesnt need to shift all the time. For certain engines they recommend light load cruising speed starting from 850 rpm.
newmercman:
Some scary reading here.Manufacturers spend untold millions developing the most efficient drive train they can and drivers run a gear down from top because they know better!
And drivers moan about companies that remove the manual function from autoshift boxes!
To the OP, yours sounds wrong though, there’s high gearing and then there’s madness, if yours is really running at 950rpms at 90km/h then you have a rear axle ratio for a direct drive top gear and an overdrive gearbox.
Or more than likely a dodgy sensor or somesuch electronic wizardry that’s not behaving itself.
also manufactors spend millions on the ecu, i spend £450 on said ecu and i make it better 
if hes running at 950 rpm then hes not running at 90kph more like 85 if hes lucky
V8Lenny:
For certain engines they recommend light load cruising speed starting from 850 rpm.
The manufacturers are working on some really clever technology. 
The next move will possibly be making something similar work at high load along the lines of sub 1,000 rpm peak torque outputs.Which would probably be a game changer regards fuel efficiency. 
newmercman:
Some scary reading here.Manufacturers spend untold millions developing the most efficient drive train they can and drivers run a gear down from top because they know better!
And drivers moan about companies that remove the manual function from autoshift boxes!
To the OP, yours sounds wrong though, there’s high gearing and then there’s madness, if yours is really running at 950rpms at 90km/h then you have a rear axle ratio for a direct drive top gear and an overdrive gearbox.
Or more than likely a dodgy sensor or somesuch electronic wizardry that’s not behaving itself.
That’s a bit arrogant my friend. After all, there is no one size fits all, no matter what the manufacturer would like us to think.
I wonder if you have any idea of the terrain we predominantly operate in. eg. We have a journey of around 120 miles to the nearest motorway or dual carriageway. I have not encountered one modern truck, manual or automatic, which will hold top gear at 40 mph, you may know better though, and I shall be pleased to hear from you.
Also, regarding investment by manufacturers in their trucks. Some of them have certainly invested eye watering amounts in their products, and they are still no where near up to the job.
I am an owner operator myself, and efficient operation is an absolute priority. You are quite dismissive of drivers, but I can tell you that there are many very able and conscientious drivers in this area, mostly working for small companies to whom they are quite dedicated, and who would not deliberately waste their employers fuel.
Horses for courses lad, horses for courses!
Old John:
newmercman:
Some scary reading here.Manufacturers spend untold millions developing the most efficient drive train they can and drivers run a gear down from top because they know better!
And drivers moan about companies that remove the manual function from autoshift boxes!
To the OP, yours sounds wrong though, there’s high gearing and then there’s madness, if yours is really running at 950rpms at 90km/h then you have a rear axle ratio for a direct drive top gear and an overdrive gearbox.
Or more than likely a dodgy sensor or somesuch electronic wizardry that’s not behaving itself.
That’s a bit arrogant my friend. After all, there is no one size fits all, no matter what the manufacturer would like us to think.
I wonder if you have any idea of the terrain we predominantly operate in. eg. We have a journey of around 120 miles to the nearest motorway or dual carriageway. I have not encountered one modern truck, manual or automatic, which will hold top gear at 40 mph, you may know better though, and I shall be pleased to hear from you.
Also, regarding investment by manufacturers in their trucks. Some of them have certainly invested eye watering amounts in their products, and they are still no where near up to the job.
I am an owner operator myself, and efficient operation is an absolute priority. You are quite dismissive of drivers, but I can tell you that there are many very able and conscientious drivers in this area, mostly working for small companies to whom they are quite dedicated, and who would not deliberately waste their employers fuel.
Horses for courses lad, horses for courses!
Absolutely, there isn’t a one size fits all lorry, which is why each and every manufacturer has an options list. On that list you can specify different final drive ratios. Obviously a used lorry with the right specs is harder to find, but if you need a lorry a bit different from the common or garden fleet spec trunker type lorry, you need to shop around to find something suitable.
As for a lorry that will do 40mph in top gear, how about a roadsweeper? Now that may sound flippant, but seriously that’s about all you’ll find with a gear spread that allows 40mph top gear cruising. This situation is the reason behind multi ratio gearboxes, a truck set up for high speed motorway running will need to drop a cog or two for 40mph cruising. In those situations running at 1400rpm is more often than not a good speed, 40mph roads have bends, hills, junctions and traffic, so it allows you to shave off a few mph and regain speed without shifting gears.
I’m not dismissive of drivers per se, but a driver that splits a gear to keep an engine designed to cruise in top gear at very low rpms revving a bit higher because he thinks he knows better is a completely different story.
I feel the same about owner drivers or hauliers that complain about high fuel costs and low fuel consumption and then see that they’ve totally destroyed the countless hours of wind tunnel testing and CAD design to get the best aerodynamic package by bolting half a mile of spot light clad scaffolding on the roof of their lorries.
Now before the bling boys start on me, I’m not saying a few extra lights aren’t necessary on some roads, or that nobody should tart up their lorry, I like a tasted up lorry, but if you do that sort of thing, then fuel economy and efficiency are not at the top of your list of priorities.
Fowler Welch had a few of these useless dogs a few years ago - geared incorrectly. Only realistic use of 12th gear was downhill M’way running or unladen.
That gearing sounds about right from some of the 420/440 Scanis i’ve driven, and its shocking how economical one can be if you can keep the revs under 1000 continually, and you can unless at full weight in poor terrain if you drive it manually, and Scanis are miles better to drive manually.
Believe it or not i’ve genuinely seen over 15mpg average for the day when i did agency work for Asda George (so admittedly no weight to speak of) with a 420 driven manually on a 2 drop run to London, never went above 50 and kept the engine to below 1000rpm the whole day, best i’ve ever got from a lorry and sad enough to take a pic of the dash readout at the time.
As for gearing, i had a proper ■■■■■■■ engined Sed Ack that cruised at a genuine 70mph @ 1100 rpm, so 950 @ 55 is about right.
Isn’t that what Diesels were all about, well till they ruined the bloody things with all this emission ■■■■■■■■, letting them lug.
Thanks for the comments
It definitely does 90kmh at 950rpm. The truck has been maintained by scania for all its life so I’m guessing by some of the comments it’s probably normal for it to be sitting at 950 but is it healthy for it to keep changing down to 11th? As some of you know opticruise isn’t the sharpest of changing gears and sometimes the truck goes up an incline and realises it’s in the wrong gear and knocks it down to 11th 1/4 way up the incline and then obviously you lose the momentum!!
Is the only option to change the diff? What would you guys suggest doing? Btw it’s a 520 so perhaps it’s designed to get best fuel economy but I’m averaging 7.5/8mpg. I’ve got other trucks giving me minimum 9/9.5mpg for the same work
JSingh:
Thanks for the commentsIt definitely does 90kmh at 950rpm. The truck has been maintained by scania for all its life so I’m guessing by some of the comments it’s probably normal for it to be sitting at 950 but is it healthy for it to keep changing down to 11th? As some of you know opticruise isn’t the sharpest of changing gears and sometimes the truck goes up an incline and realises it’s in the wrong gear and knocks it down to 11th 1/4 way up the incline and then obviously you lose the momentum!!
Is the only option to change the diff? What would you guys suggest doing? Btw it’s a 520 so perhaps it’s designed to get best fuel economy but I’m averaging 7.5/8mpg. I’ve got other trucks giving me minimum 9/9.5mpg for the same work
Has it got a manual option.If so leave it in manual and experiment with downshift and upshift points.Bearing in mind that,according to it’s graphs,it will put out around 380 - 500 hp under full load between around 1,000 rpm - 1,300 rpm.While anything much over 1,400 rpm is realistically just burning money bearing in mind that it’s only putting out less than an extra 20 hp at 1,900 rpm than at 1,400 even under full load.On that note who needs revs or a ‘run’ at the hills although 950 rpm at anything other than very light engine load could possibly be costing fuel rather than saving it.While it’s my bet that any of the big power Scanias would do better on fuel with an 18 speed Fuller,to allow the driver to optimise engine speeds under all types of engine load conditions,than a 12 speed auto.