DC5R vs DC5S: fuel economy.

you should never skip gears regardless of the car...

Of course they do...

If your gearbox is standard using syncros, you'll be working them hard to match the rpms your car is suppose to be @ with your new gear...

And you shouldn't neutral anyway unless at idle cause you've given up control on the car. Always in gear, you never know when you have to accelerate to avoid something or use engine braking.