The gaffers loved them and most drivers hated them as Saviem said if you did not have a wedge or stick to jam the throttle open you had a knee ache I only drove a Big J with a 180 and a Atkinson Venturer with a 240 and the 240 was crap at the side of my 250 ■■■■■■■ viewline and not much difference on fuel when we ran together with identical loads plus the 240 had a 10 speed fuller while I had a ZF straight 6. I think the fuel consumption was due to the gearing as the 240 would only do around 38/9 with the 10 speed where as my ■■■■■■■ would do 46 with a 6 speed box and loaded we had to keep around 30 to 35 for the tyres so I would be running at lower revs.
cheers Johnnie 