Originally Posted by
JDNSW
I must admit I was being generous about the 30mpg. I have got about 27-28 on the odd occasion from the swb Series 2 I owned in the early sixties - secret is to start with an area with no hills, smooth straight roads and no traffic, and drive (smoothly) at 30mph or less. I did this when I was sightseeing round the countryside at weekends just after I started living in Roma in 1963. On one occasion in my lwb 2a diesel, driving through northern SA from the Simpson to Port Augusta in 1966 I managed 36mpg - which did surprise me.
The quoted maximum torque rpm for the 2.25 petrol is 2500rpm - the diesel is 1750rpm. A quick Google shows the Holden motors with maximum torque at lower RPM, typically around 2000 (figures vary for different versions). Both Holden and Landrover engines give maximum horsepower at around the same figure 4000 for the Holden and 4250 for the Landrover. But driving experience suggests that the shape of the torque curves must be quite different! I suspect that the Holden engine is deficient on torque compared to the Landrover at really low engine speeds, 1000 - 1500, which I find I am often using in my 2a offroad or on rough tracks, although you'd think the six cylinders would help there. Probably influenced by carburetion, possibly camshaft, and the longer intake manifold on the six may cause problems at low speed - if you think about it, with a four such as in the Landrover you can have the same length intake to all cylinders - impossible with a six and one carburetter (in fact, you need three). The Holden may well be set up so that a standing wave resonance in the intake manifold gives a very sharp torque peak.
John
