In terms of extreme petrol saving, you can also...
(1) When in town:
i. Try to roll down hills as much as possible when warming up (and other
times), so that engine is idling. This is illegal but does save momentum
ii. Try to conserve your momentum - brake as little as possible!
iii. When warmed up, only press the accelerator about 1/4 or 1/2 way -
just enough to get some accleration. If you press it more, you don't get
much more acceleration but waste a lot more fuel.
iv. When accelerating, rev up to 3400rpm in the gears, using only partial
throttle. The engine will 'enrich' the mixture when (i) the engine goes
above 3400RPM, *or* you put more than a certain amount of throttle.
(note : 3400rpm is for a CA18ET engine, but probably a similiar-ish value
on the Micra)
v. For extreme economy... If you drive behind lorries on the motorway, then
the wind resistance is dramatically reduced, meaning, for example, that
you can get 50mpg from a CA18ET bluebird, which should only get about
40mpg. If you don't believe this, try putting your hand slightly out of
the driver's window, and see the difference between driving behind a
lorry, and on the open road. Don't drive too close though, because it is
dangerous.