Thread: Fuel consumption

Yeah... we know that 100 will use less than 110... but is there a point gearing and efficiency are more important than wind speed... ie where say a constant 70 will use less than a constant 60.

I know I haven't got the patience to work it out, but it has puzzled me in the past

Originally Posted by Redback

The Disco with the low RPM was labouring the engine, this will always make a vehicle use more fuel, especially heavy 4WDs.

Baz.

In this case most probably wat speed is 1750rpm in 4th on a disco anyways??

should be just over 60kph. (61.5)

oops, i have not read every post however this was an interest test that my mate did towing his caravan with a 100 series 'turboed manual gearbox' from brisbane to melbourne

he ended driving all the way in 4th gear at or around 90-95km/h

he said the differance between holding the same speed in 4th as to fifth gear was big, in fifth gear the accelerator was pushed more and the egt's were higher but rpm was lower than when in 4th

he returned his best fuel economy driving in 4th at higher rpm but cooler egt's

i tried the same with my 300tdi....i just could not let my little motor spin at higher rpm's for extended periods, i guess its lack of a few cubes or fourth gear gearing

either way i still pull better fuel economy than him be it that i'm a little slower up the hills

Originally Posted by Grimace

In this case most probably wat speed is 1750rpm in 4th on a disco anyways??

No idea, but 1750rpm in a V8 is way below the torque curve, don't V8s idle at 1000rpm there abouts, even a 300TDi would be below the torque curve, wouldn't it ??

Baz.

nope the curve for most rover engines is either well and truely underway by those revs and 600-700 is normal idle (or thereabouts) with the aircon off for most of them, a series 2.25 petrol can be made to idle at a shade over 350 rpm, you can almost make out individual cylinder firings at that speed.