Foxstein:
You might only be doing 1200rpm but if your foot is flat to the floor you might as well be red lining it.
As has been said Foxstein, that is totally wrong. Specific fuel consumption is measured as; g/KWh
That is g= grams (absolute mass) of fuel divided by KW= killowats (power) h= hour
so, a specific fuel consumption of 192 g/KWh is worked out as above. (am I boring you yet?)
@ 1,200 rpm a Scania R620 (being driven, not freewheeling) is producing about 430KW so if the SFC was 192 g/KWh, each hour it would use 82,560g’s of diesel.
@ 1,900 rpm its producing 540 KW (again under power) so would use 103,680g’s of fuel each & every hour.
So there it is, keeping the revs @ a constant 1,200 rpm rather than 1,900 it will use 21,120g’s LESS diesel which is almost a 25% saving.
You’ve got some high revving trucks. According to the revolutions gauge in the instrument window on my trundlewagon she only revs at 12 rpm when cruising, so once every 5 seconds…
switchlogic:
You’ve got some high revving trucks. According to the revolutions gauge in the instrument window on my trundlewagon she only revs at 12 rpm when cruising, so once every 5 seconds…
Harley trundler then.Only has an ignition stroke at every other lamp post.
I’ve been called worse, in fact I was called a “queue jumper” the other day!!!
Imagine my shock when he went on to tell me he’d ‘torch’ my truck & ‘do me in’ if I did it again!!! I jumped out & when the bloke saw that I was about a foot taller than him with a far worse attitude than his, he skulked off back to his yellow ex Philsons Superspace cab Daf.
Foxstein:
@ 1,200 rpm a Scania R620 (being driven, not freewheeling) is producing about 430KW so if the SFC was 192 g/KWh, each hour it would use 82,560g’s of diesel.
@ 1,900 rpm its producing 540 KW (again under power) so would use 103,680g’s of fuel each & every hour.
So there it is, keeping the revs @ a constant 1,200 rpm rather than 1,900 it will use 21,120g’s LESS diesel which is almost a 25% saving.
Make of that what you will, I’m off for a kip
Ross.
But at 1900 rpm pedal on the floor you will be going faster or accelerating quicker. Same power at 1900 rpm as at 1200 rpm the difference will be smaller but 1900 rpm will use more fuel anyway because pumping losses are greater.
Best BSFC will always be at max torque, that’s why you want to keep the pedal on the floor when climbing or accelerating, at light throttle the BSFC is much worse.
OVLOV JAY:
Wonder if we can keep it going til someone gets post 730
I’ve an idea.
So as I understand it the best running gear for a high power truck is a 6x2 midlift…
#730 and beyond.
Nah, it’s gotta be a tag…
I wonder if anybody else has an opinion…?
I have absolutely no idea how anyone could suggest that anything other than a 4x2 unit is even close to efficient!!!
Ross.
Any Aussie types around to give us an upside-down perspective?
Too late I’ve already posted it further back.Good old fashioned Ozzy outfit pulling two trailers loaded at 80 t gross with a 1970’s technology CAT 3408 and reckons he’s getting 4 mpg at Oz type speeds not Brit ones.
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