Ok here is the Low down

Last week I put 15.44Litres in my Ride and got 145k's out of it Driving Briskly in City Driving
Which the Top speed acheived was 90k's an hour for a 3 minute stretch Changing gears at around 4000-4700rpm

This Week, I put 15.55litrs into it and Drove like a Granny, not once did the tacho exceed 3200rpm yet I got a Lowly 80k's to the Tank WTF !!!!

It seems the more conservatively I drive the more Damn Fuel it uses.. I mean I honestly thought that Granny shifting was going to help me save fuel NOT BURN IT UP !!!

so is there such a thing as driving too soft ???

Its a manual so I can change the Gears when I want to..

The most economical speed is around 70 kmph afaik.
If you drive everywhere slowly you will get terrible economy.

How do you know how much was in ur tank though. I assumed u didnt run it to empty to test it out.

With such little distances it's probably not the best test.

Nope I didnt Run it till empty,, just till the Fuel light Stayed on and it occurs at the same point on the Fuel Gauge..

Each time the Fuel amount refuelled was written down and the Odometre reset Same Path at the Same time with no variation in Traffic ( Yes I live in a "Rural" area so traffic was not a Varying factor)

what tim said about the small samples not making good tests is spot on, also - the engine is having to work harder to increase the velocity of the car at low RPM. Sure you're not pumping as much fuel per second into it - but you're taking alot longer to get up to the same speed as if you were holding the gears longer or downshifting.

I'm no expert on the topic, so I will gladly stand corrected if I'm way off base here, but I'd have to say that the most economical rev range would be closer to the rev range where the car makes peak power (or maybe peak torque). In anycase - this would be closer to the revs you mentioned from your first example.

2000-3000 rpm is a good RPM range for sedate cruising, but if you're not letting your engine rev when accellerating - I'll bet it's reducing your fuel efficiency.