There's a distinction to be made — the most efficient way to accelerate is to use every gear and use a very light touch on the accelerator, changing up each time before the revs get very high at all.

On the other hand, if you have already accelerated in, say, 2nd gear to a speed where you can easily use 4th or 5th, then there's no reason to oblige yourself to engage every other gear in between — there's nothing wrong with just bunging it into the gear you want.

For maximum efficiency, plan far enough ahead that you don't need to touch the brakes. If you're braking *now*, then you could probably have lifted your foot off the accelerator 30 seconds ago instead, thus making those 30 seconds more economical. That's not always possible of course — things change on the road, hazards appear, other people brake, etc. etc. — but if you can see that the traffic light 500 yards away will be red when you reach it, start coasting now; off-sliproads are made for coasting, and if there's no one behind you, you might as well start on the dual carriageway itself 200 yards before the sliproad; [add your own examples here]
(Sir Reginald Slapknackers last slapped his knackers at, Tue 5 Apr 2011, 21:03, Reply)