All the manufacturers of trucks have spent millions designing their particular engine to be most efficient at around 56 mph. What makes some spotty oik in the transport office think that he can do better by geting the fleet restricted to 52 or 50 mph.
Surley, if this was the optimum speed, then would the manufactures have designed the truck around this?
From previous posts on here you will find that you are right.
if a truck is set at 56mph and shows 56mph on the tacho, then you should be able to calculate the correct mpg.
However if your truck is set at 50mph but shows 56mph on the tacho. then the spotty oyk thinks you’ve done 560miles to the fuel used, not the 500miles that you’ve actually done. “ok, i know, you’ve no chance of 560miles in the uk”.
also if the speed is set too low, then the trucks engine will be labouring, and will use more fuel as it will lack momentum.
if 56 in top gear puts the revs in the middle of the green band and 50 in top gear puts the revs at the low end of the green band - which is more economical 
limeyphil:
From previous posts on here you will find that you are right.
if a truck is set at 56mph and shows 56mph on the tacho, then you should be able to calculate the correct mpg.
However if your truck is set at 50mph but shows 56mph on the tacho. then the spotty oyk thinks you’ve done 560miles to the fuel used, not the 500miles that you’ve actually done. “ok, i know, you’ve no chance of 560miles in the uk”.
also if the speed is set too low, then the trucks engine will be labouring, and will use more fuel as it will lack momentum.
Why would it do that?
SWEDISH BLUE:
All the manufacturers of trucks have spent millions designing their particular engine to be most efficient at around 56 mph. What makes some spotty oik in the transport office think that he can do better by geting the fleet restricted to 52 or 50 mph. Surley, if this was the optimum speed, then would the manufactures have designed the truck around this?
We are advised (not limited) to drive at 52mph for obvious fuel economy reasons.
There are some firms who have limited their trucks, Maritime for instance, (who you would think would need to get a move on sometimes), this is obviously for fuel economy, and I doubt, instigated by some spotty oik!!
there are some that do worse at 52mph than at 56mph. with some there is no change. the main thing you lose by going slower is a good driver when he falls asleep and runs into a ditch. and about an hour per day.
Is what is saved by the fuel economy gained by a lower limited speed,more than the hours loss of productivity in a working day?
I recently moved a wide load from Santander down to Gibraltar, the Spanish wide load permit required that the speed of the truck should not exceed 70Km/h.
This speed in a 440 Magnum in top gear puts the revs just inside the bottom of the green band, so it would be reasonable to assume that the journey would be economical - it wasnt!!
The problem was that I was constantly changing down as the vehicle had no real forward momentum, so even the slightest, normally un-noticeable uphill gradient required a down change, sometimes two. This of course meant higher revs and even slower road speed, which of course ate fuel.
limeyphil:
there are some that do worse at 52mph than at 56mph. with some there is no change. the main thing you lose by going slower is a good driver when he falls asleep and runs into a ditch. and about an hour per day.
So a driver who has no motorways to use on his journey (legal max speed 50 on a dual) may fall asleep 
- EH 
ROG:
limeyphil:
there are some that do worse at 52mph than at 56mph. with some there is no change. the main thing you lose by going slower is a good driver when he falls asleep and runs into a ditch. and about an hour per day.So a driver who has no motorways to use on his journey (legal max speed 50 on a dual) may fall asleep
No. the bloke i had in mind was on the motorway.
“A mate of mine” has done 60-65mph in the past and worked, well lets just say very long hours, and he has been ok. but the same bloke will feel very tired after 10 hours on a 52mph limiter.
limeyphil:
the bloke i had in mind was on the motorway.“A mate of mine” has done 60-65mph in the past and worked, well lets just say very long hours, and he has been ok. but the same bloke will feel very tired after 10 hours on a 52mph limiter.
Must be a personal phsycological thing with that particular driver as I have never come across a driver with a problem on this issue
bestbooties:
Is what is saved by the fuel economy gained by a lower limited speed,more than the hours loss of productivity in a working day?
Driver A travels in 8hrs @ 56mph = 448miles at an average of 10mpg = 44.8 gallon.
Driver B @ 52mph takes 8.6hrs to cover 448miles @ 10.5mpg = 42.6 gallon.
Difference in fuel is 2 gallon= approx £10
Difference in time is 1/2 hour = approx £5
So in this example the company saves a tenner, driver gets a fiver, every ones a winner 
Times that by say 200 drivers and you save a tidy bit.
Note:- mpg figures are only a guesstimate, what it does show is that a small improvement in mpg figures can add up to a lot of money at the end of the year.
redboxer850:
Difference in time is 1/2 hour = approx £5
actually, it’s more like a £37.50 loss.
truck turnover £75 per hour.
limeyphil:
redboxer850:
Difference in time is 1/2 hour = approx £5actually, it’s more like a £37.50 loss.
truck turnover £75 per hour.
Ahh, forgot that bit 
surely there must be a saving somewhere if firms like maritime are limiting their trucks
redboxer850, that calculation reminded me of when I took my CPC (proper one not driver one).
You’re not one of these “spotty oiks” are you? 
“Spotty oiks” - always makes me laugh!
Clearasil would do a roaring trade if they visited every transport office in the land!! 
Dazza:
redboxer850, that calculation reminded me of when I took my CPC (proper one not driver one).You’re not one of these “spotty oiks” are you?
“Spotty oiks” - always makes me laugh!
Clearasil would do a roaring trade if they visited every transport office in the land!!
Sorry to disappoint you, I am not a “spotty oik”
Maybe they should simply remove the engines altogether and shackle up a team of horses! Think of the diesel that would save 
… Hey Ho Silver, Away!
Ragnarok:
Maybe they should simply remove the engines altogether and shackle up a team of horses! Think of the diesel that would save
How about going back to the days of the bloke walking in front of a vehicle with a red flag?
This would have enormous benefits including creating useful employment for thousands.
limeyphil:
ROG:
limeyphil:
there are some that do worse at 52mph than at 56mph. with some there is no change. the main thing you lose by going slower is a good driver when he falls asleep and runs into a ditch. and about an hour per day.So a driver who has no motorways to use on his journey (legal max speed 50 on a dual) may fall asleep
No. the bloke i had in mind was on the motorway.
“A mate of mine” has done 60-65mph in the past and worked, well lets just say very long hours, and he has been ok. but the same bloke will feel very tired after 10 hours on a 52mph limiter.
i think i can see where limeyphil is coming from-my mate at work, hes a 31 yearold boy racer who drives a civic type-r and his car lives in at the rev limiter! he says when hes driving one of our trucks at 56mph, he gets severely bored!
but i can where see where ROG is coming from aswell, it maybe all just phycological!! im fine sitting at 56mph doin 300miles, its ever since ive had me kids, my everyday driving in the car has slowed down!!
redboxer850:
bestbooties:
Is what is saved by the fuel economy gained by a lower limited speed,more than the hours loss of productivity in a working day?Driver A travels in 8hrs @ 56mph = 448miles at an average of 10mpg = 44.8 gallon.
Driver B @ 52mph takes 8.6hrs to cover 448miles @ 10.5mpg = 42.6 gallon.
Difference in fuel is 2 gallon= approx £10
Difference in time is 1/2 hour = approx £5
So in this example the company saves a tenner, driver gets a fiver, every ones a winner
Times that by say 200 drivers and you save a tidy bit.
Note:- mpg figures are only a guesstimate, what it does show is that a small improvement in mpg figures can add up to a lot of money at the end of the year.
Thats roughly how its worked out with us. I’m sure our MPG has improved by at least 1 MPG, i’ll post up when i know exactly for sure.
limeyphil:
actually, it’s more like a £37.50 loss.
truck turnover £75 per hour.
When the work is there for them Phil that might be right, as it is for us its just a job or two then finish. We ain’t losing jobs because we are going slower, we are just taking longer to do them
Difference in fuel is 2 gallon= approx £10
More like £7.70 approximately!
However if your truck is set at 50mph but shows 56mph on the tacho.
Then you need a new tacho - or at least a recalibration! Aren’t they supposed to be accurate to within something like ± 2kph?