All of the lorries in that comparison averaged around 40MPH. Are you saying a 2800 would have averaged 50 on the same test? Why not check some old magazine roadtests and pull out the motorway figures? If you were to post some actual facts, rather than meandering, unsupported doggerel, the rest of the forum may consider your posts in a better light.
[zb]
anorak:
All of the lorries in that comparison averaged around 40MPH. Are you saying a 2800 would have averaged 50 on the same test?
No the test reflected the test route.What I’m saying is could the 8 LXB have beaten the old 2800 at an average speed well into the 50’s on a run which was mostly on the motorway.If it could there were a lot of people who obviously got it all wrong to this day by going for turbocharged motors when an old naturally aspirated 8 cylinder Gardner could have done a better job. 
So a 2800 Daf would give a 10mph faster average speed than a 290 F88, 111 etc 
■■■■■■■■ it would
Remember I’ve driven around that test route many times 
For your information the Daf 95-530 (which I did the road test on) only managed an average speed of 46.33mph around a slightly revised test route, it achieved 7.98mpg on that test, due to a slightly higher set speed limiter the Daf was a little bit faster around the whole route than the 164-580 Scania
And you’re trying to tell me that a sub 300hp lorry would be faster than that
newmercman:
So a 2800 Daf would give a 10mph faster average speed than a 290 F88, 111 etc■■■■■■■■ it would
Remember I’ve driven around that test route many times
For your information the Daf 95-530 (which I did the road test on) only managed an average speed of 46.33mph around a slightly revised test route, it achieved 7.98mpg on that test, due to a slightly higher set speed limiter the Daf was a little bit faster around the whole route than the 164-580 Scania
And you’re trying to tell me that a sub 300hp lorry would be faster than that
No nmm you’ve got it all wrong again.Nothing to do with any ‘test route’.The route which I’m referring to is for example Feltham to our old Leeds depot around 620 kms round trip with just a few miles at each end done off the motorway done easily in around 3 1/2 hours each way most nights in reasonable conditions.Any Gardner would have been struggling at Loughborough let alone all the rest of the hills after that on the M1.
If everyone is right about all this Gardner bs then,as I’ve said,you’re all going to have to re write the whole history of truck engine development since at least the early 1970’s which means that DAF have gone out of business years ago and it’s ERF etc that are still beating all the opposition with Gardner 8 LXB’s fitted in them.
By the way what speed limiter .
It is generally accepted that turbocharging gives a marginal improvement to the engine’s efficiency, due to the energy it salvages from the pressure drop, across it, in the exhaust (Of course, the increase in power may be more than marginal, according to how much boost is applied). It is to Gardner’s credit that it could build a naturally aspirated engine with superior SFC to all of the turbocharged competition in 1975. The LXB was an exceptionally clever piece of work, and the roadtest results posted above are a practical demonstration of this. It was only later, when low-speed, high torque turbocharged engines became popular, that the Gardner was beaten.
There’s a flaw in your argument though Carryfast
You only have experience of the Daf under those conditions, you never tried anything in comparison, if you had you wouldn’t be making the statements that you are, the figures don’t tell lies, the 8LXB was faster and better on fuel than all of its competitors around a test route that encompasses every kind of terrain you would encounter during a journey within the British Isles. The tests are done under strict conditions so that comparisons can be made between vehicles, to the point that you could compare the 8LXB with any present day lorry on the same route
Your 2800 may have been faster than the 6LXB/C ERF and Seddon atkinsons that you’re using as comparisons, but I’m quite sure that any fool could’ve told you that anyway, that is like comparing a Greyhound to a Labrador
But I must congratulate you on one thing…Not a word about two stroke Detroits for weeks now…Well done
[zb]
anorak:
It is generally accepted that turbocharging gives a marginal improvement to the engine’s efficiency, due to the energy it salvages from the pressure drop, across it, in the exhaust (Of course, the increase in power may be more than marginal, according to how much boost is applied). It is to Gardner’s credit that it could build a naturally aspirated engine with superior SFC to all of the turbocharged competition in 1975. The LXB was an exceptionally clever piece of work, and the roadtest results posted above are a practical demonstration of this. It was only later, when low-speed, high torque turbocharged engines became popular, that the Gardner was beaten.
The fact is any naturally aspirated truck of the 1970’s was beaten by the 2800.It seems obvious that the turbocharged 680 motor was just about the only credible British engine that could have competed with the 14 Litre ■■■■■■■■■■■■■ is why DAF is where it is today and no one,with any sense,would use a naturally aspirated motor to power anything these days even at 56 mph max let alone 60-65 mph before limiters.The Gardner engine,and more importantly those misguided buyers who kept the thing inproduction for so long,were a significant contributor to the demise of the British truck manufacturing industry.
Another flaw CF
Daf went bankrupt a few years ago, they were bailed out by the Dutch Government and then sold to Paccar, not such a succesful company as you think
newmercman:
There’s a flaw in your argument though CarryfastYou only have experience of the Daf under those conditions, you never tried anything in comparison, if you had you wouldn’t be making the statements that you are, the figures don’t tell lies, the 8LXB was faster and better on fuel than all of its competitors around a test route that encompasses every kind of terrain you would encounter during a journey within the British Isles. The tests are done under strict conditions so that comparisons can be made between vehicles, to the point that you could compare the 8LXB with any present day lorry on the same route
Your 2800 may have been faster than the 6LXB/C ERF and Seddon atkinsons that you’re using as comparisons, but I’m quite sure that any fool could’ve told you that anyway, that is like comparing a Greyhound to a Labrador
But I must congratulate you on one thing…Not a word about two stroke Detroits for weeks now…Well done
It’s my contention that in this case those ‘tests’ actually just distorted the real world operation of many/most/ trucks in that the criterea of being economical at 40 mph average speed isn’t going to work in an operation that runs between depots or destinations which involve mostly motorway operation in which the objective is to go up the hills as close to the speed that you’re able to run on the flat as possible.
Not so different to the US interstate system where the Detroits roamed and sorted out their ■■■■■■■ and CAT rivals,after all. 
Carryfast:
The fact is any naturally aspirated truck of the 1970’s was beaten by the 2800.
Unless the DAF was way ahead of all the engines in the above comparison, it would not have beaten the 8LXB, would it? Are you saying that it was so significantly superior to the 111 or 88? If so, why did operators who bought those vehicles not buy the 2800?
Carryfast:
Not so different to the US interstate system where the Detroits roamed and sorted out their ■■■■■■■ and CAT rivals,after all.
Read any US forum. Detroit did not “sort out” ■■■■■■■ and Cat. Generally, their opinions favour the three engines equally.
There is quite a lot of information in this test report including calculations which relate payload to MPG and average MPH . There is also a section comparing the motorway speeds of the vehicles. It does not state the test route, but does say " How many trucks do you know that will return 8.5 mpg averaging over 50 mph fully loaded over the hilliest motorway stretches in the country?" What is clear is that the route includes M6 Charnock- Tebay, M18 Doncaster -Derby, Ashbourne hill and Ravenstonedale hill.
The vehicle engines are described:
Saviem: turbo MAN 2156 lightly turbocharged with average torque rise.
Berliet: High torque rise to give very high torque at low and medium speeds at the expense of top end output.
The motorway speeds and mpg are:
ERF 50.92 mph 8.48 mpg
Saviem 58.8 mph 7.88 mpg
Volvo 56.46 mph 7.533 mpg
Berliet 53.22 mph 7.01 mpg
Scania 55.15 mph 7.51 mpg
Foden 54.30 mph 7.53 mpg
Buffalo 48.8 mph 7.53 mpg
DAF 48.5 mph 7.53 mpg
Further info imperial units:
ERF ulw: 6.44 trailer ulw: 4.98 payload: 21.09 test gvw: 32.48
Berliet ulw: 6.92 trailer ulw 4.33 payload: 20.59 test gvw 31.85
Saviem ulw: 6.22 trailer ulw: 4.114 payload: 21.497 test gvw 31.831
There are enough figures here to make comparisons between the three vehicles for which full data is presented. One could juggle the figures to adjust the unladen trailer weight and payload since one trailer is significantly heavier in order to get nearer to parity, but there is nothing that can be done with the GVW without affecting the results.
The calculations made by Truck are to multiply payload by mpg and then multiply the result by the average speed:
ERF payload x mpg x overall average mph
6193
ERF as above but x motorway speed
9106
Berliet
5621
7681
Saviem
6295
9960
If anyone can find a Truck magazine road test for the DAF 2800 during the 1974- 78 era then we can compare it.
I am quite sure Saviem will be most interested.
Now dug out some old brochures.
“The 8LXB develops 240bhp at 1850rpm and a maximum torque of 695 lbft at 1000 to 1200rpm. It does not fall below 98% of this value over the speed range from 800 to 1850 rpm.”
“The specific fuel consumption at 240 bhp 1850 rpm is .333 lb/bhp/hr. At mid speed, at some 10% below maximum torque it will record a sfc of .325 lb/bhp/hr.”
“Net calorific value of fuel 400 BTU/lb. Specific gravity (60deg F) 0.830”
The 6LXCT brochure gives info that enables a conversion to metric units, by quoting at 1400 rpm (max torque)sfc is 193g/KW/hr or .318 lb/bhp/hr.
at 1900rpm 199g/KW/hr or .328 lb/bhp/hr
As someone who has owned lorries and paid the bills, I’d take the slightly slower Gardner at 8.48mpg over any of the others, which is the same approach all the ‘backward thinking’ hauliers took
Funny that, the blokes that paid the bills and ran the businesses had a different criteria to leadfooted lorry drivers who modelled themselves on Kris Kristofferson
newmercman:
Another flaw CFDaf went bankrupt a few years ago, they were bailed out by the Dutch Government and then sold to Paccar, not such a succesful company as you think
Maybe but I’m guessing that a lot more people bought DAF’s than Gardner powered Brit heaps since the 1970’s to date .
Or maybe I’m wrong.
More good stuff from cav551. The Gardner specifications are still impressive in 2012- current lorry engines are barely any better than 193g/kWh, albeit strangled with emissions rubbish. Those Truck Magazine tests were sometimes a bit dodgy. Why did the Saviem have a motorway speed about 5-8MPH faster than the others, all of which were grouped about the same speed? The SM16-280 only had 240BHP net (the 280 figure was SAE,which is gross gross!), so it was no more powerful than any of the others. I wonder if it was a case of the test vehicle being “specially prepared?” Either that or the salesman in the passenger seat telling the magazine’s driver to thrash it. NMM- can you shed any light on this, with your experience of magazine driving?
cav551:
Now dug out some old brochures.“The 8LXB develops 240bhp at 1850rpm and a maximum torque of 695 lbft at 1000 to 1200rpm. It does not fall below 98% of this value over the speed range from 800 to 1850 rpm.”
“The specific fuel consumption at 240 bhp 1850 rpm is .333 lb/bhp/hr. At mid speed, at some 10% below maximum torque it will record a sfc of .325 lb/bhp/hr.”
“Net calorific value of fuel 400 BTU/lb. Specific gravity (60deg F) 0.830”
The 6LXCT brochure gives info that enables a conversion to metric units, by quoting at 1400 rpm (max torque)sfc is 193g/KW/hr or .318 lb/bhp/hr.
at 1900rpm 199g/KW/hr or .328 lb/bhp/hr
It would be interesting to see what the 240’s SFC is between 240 hp and the 310 hp max hp output of the DKS motor.If it could have actually got there that is.
newmercman:
As someone who has owned lorries and paid the bills, I’d take the slightly slower Gardner at 8.48mpg over any of the others, which is the same approach all the ‘backward thinking’ hauliers tookFunny that, the blokes that paid the bills and ran the businesses had a different criteria to leadfooted lorry drivers who modelled themselves on Kris Kristofferson
I think someone is confusing maximum speed reached on the flat with average speed.I’ll believe that a Gardner powered heap could ever manage over 50 mph average on a motorway with decent hills on it if I’d have ever seen it.Even the DAF was only just ahead of that with 310 hp.Funny how their criteria changed fast enough when they eventually caught on that the Gardner wasn’t the money making machine it’s made out to be though.The sad thing is that it didn’t just take out the engine manufacturer,but also all those manufacturers,who were too stupid to tell those misinformed buyers,we’re only going to put a turbocharged ■■■■■■■ in it and a decent cab on it take it or leave it,were taken down with it because of the reputation of gutless guvnors wagons stuck .
Carryfast, you lost your argument, live with it
newmercman:
Carryfast, you lost your argument, live with it
I was going to say exactly the same thing about the Gardner supporters but you got there first.
Yes, let’s not let the facts get in the way of a good argument eh