done the first month with the artic, work wise it’s been ok, had plenty of work, thats not panned out to bad, rate wise but got a bit of a shock with the fuel, the old ERF’s averaged 10.3 mpg which is a lot better than i expected on a combination of local and motorway and actually slightly better than i was getting with the rigid. 
Blimey Paul, you sure you’ve done the maths right? If you have, you’ve got a good 'un there. Well done!
I wish my Merc was that good I thought I was doing well at 8-8.5 
good luck to you 
found it hard to believe me self but double checked the figures to be sure, i suppose the twin splitter and an average load of around 25t helps.
Paul, is it a m11 ■■■■■■■ in the ERF, what model is it?
it is a ■■■■■■■ ec11 380
good motor.
i’m well pleased with it, did think that 380 might be a bit under powered for the job but it pulls well and will only drop off the limiter on the steeper hills so it’s plenty good enough for the job it’s doing. not the pretiest truck on the road but i can live with that, the only criticism i would have is that it strugles for traction more than you’d think, loaded or empty it will try and spin up in any gear even if your rolling when the road’s wet.
I have the same trouble with the EC11 6x2’s but not the 4x2’s (even with the mid lift raised).
do you use the diff lock much? i’ve not tried it but i assume that you can use it when setting off and then knock it off by dipping the clutch?
No, you have to come to a complete stop to dis-engauge the diff lock, steering is almost impossible as well! 
Tramper:
No, you have to come to a complete stop to dis-engauge the diff lock, steering is almost impossible as well!
you don’t on my Daf, dipping the clutch works most times 
that’s that plan out the window then!
the m11 i had was the 380 Paul, but in a 4x2 sedd ack unit so traction was good, i couldnt fault it, on banks i let it lug down to 1000 rpm and change down 2 gears, not many hills botrhered it! and it’d uotpull a lot of stuff of a greater bhp! They are a very good lump!
Re traction: Paul, is your 5th wheel a slider? Don’t know what trailer your pulling & how deep the pin is, but might be worth a try moving the 5th wheel but watch you’re drive axle weight though.
If your’e having traction problems with a 4x2 loaded, there’s definately something amiss somewhere. Is the 5th wheel height unsually low for some reason such as low profile tyres on the drive axle?
the units a 6x2 and not a slider, pull variouse trailers form 40ft tandems to 45ft tri’s some deep pin some very shallow. i have been wondering if theres a fault with the air bags on the drive axle, they don’t seem to inflate as much as you’d think and it does carry the fifth wheel low to the point i can strugle to pick some trailers up, it’s only the basic setup with a switch on the dash to lower the back end not the box where you can lift it past level if needed and it does drive as if the lift axle has took to much weight off the drive axle, if you know what i mean?
Yes.I know exactly what you mean Paul. Its like the trailer is picking up the back end of the unit & lifting the weight off it instead of pressing down on it.
Sorry, i had in my head from somewhere it was 4x2. I remember posting to you some while back, I think you hadn’t been going long, & you were having parking/maintainence garage issues. (what happened?)
There is a standard ride height for 5th wheels (I don’t know what it is) maybe you could get it measured. Have to find out whether the quoted height is unladen or laden.
It is sounding like its running low though.
Is there a traction switch on the dash that will lift the lift axle for a minute (even fully laden) if you’re having problems setting off?
(as temporary assistance until you get to the cause)
I had a 4x2 EC11 when I first started driving for my last employer. That particular unit had loads of trouble with the suspension on the drive axle, it just couldn’t inflate properly. ERF fitted an extra air tank, but it was never really right.
I seem to remember that was quite happy to wheelspin all day long. I just put it down to the grunt produced by the 380 engine. Which would easily outpull the 420 Scania that I got as a replacement.
He also had/has a 6x2 EC11, but that doesn’t seem to have the same troubles. Although that has the option to raise or lower the suspension. Whereas the 4x2 I had could only lower it.
Not alot of help I guess, but I guess it must be a quirk of the EC11.
i can lift the axle at any time regardless of load which i do on some uphill junctions in sheffield which would be impossible otherwise.
i’ve sort of convinced myself it’s a problem with the drive axle airbags, i assume theres some sort of cut off valve that dictates how much air goes in when raising the suspension back up, could this be the prob?
it’s become more and more noticeable now that the roads are continually damp, especially in this area which is all hills and when you think that the bulk of my loads are brightbar which is loaded tight to the headboard and if anything would be front heavy, there must be something a miss i reckon.
paul b:
i can lift the axle at any time regardless of load which i do on some uphill junctions in sheffield which would be impossible otherwise.
i’ve sort of convinced myself it’s a problem with the drive axle airbags, i assume theres some sort of cut off valve that dictates how much air goes in when raising the suspension back up, could this be the prob?
it’s become more and more noticeable now that the roads are continually damp, especially in this area which is all hills and when you think that the bulk of my loads are brightbar which is loaded tight to the headboard and if anything would be front heavy, there must be something a miss i reckon.
I don’t know what tryes you’re running, or how far worn they are, but we use Michelin XDE2s,excellent wear, but terrible traction when they get to the end of their lives. Also the roads are particularly greasy at the moment. I tend to dump my middle axle at roundabouts and junctions, it comes back at 25kph, but avoi the diff lock tyres are cheaper than diffs, saying that, if it’s that greasy your skidding, you’re hardly likely to wind the diff up.