[euromodder]

Originally Posted by JohnnyRun

I was wondering what would be the best time to shift gears (in rpm's) in order to keep efficiency up. Its a '93 Civic Dx if that helps.

Traditionally, Belgian beginners were told to shift up at 20, 40, 60 and 80-90 kph.
That's 12.5 , 25, 37.5 and 50-56 mph.
Because the gearing is normally adjusted to the engine's power, this works pretty well for just about every manual car regardless of displacement or fuel type.
That's the traditional way, but it'll get you started fine.

The more ecological way is to shift earlier and accelerate at lower rpm and higher engine loading (which gives better specific fuel consumption).
Beginners are now taught to short-shift up around 2500rpm in gasoline cars - and 2000rpm on diesels.

There's plenty of hypermilers with Civics of that generation.
They'll be short-shifting as well

You'll hear and feel it when you're lugging the engine, so do some experimenting on quiet roads to see at what speeds / rpm it happens in the different gears, then avoid going that low in the rpm range when the engine has to work.


1st gear is there to get you going and for very slow speed manoeuvring only.
1st is a wildly inefficient gear.
In slow moving traffic that's too slow for steadily using 2nd, don't change down into 1st, but briefly pulse in 2nd and then push in the clutch again to glide. Try to keep it rolling, and repeat when required.


Shift into 2nd right after getting going.
I shift into 2nd within about 2 car lengths from a stop.
Some people skip 1st altogether, and start going in 2nd.

Try to always be in the highest gear the engine will cope with, for the speed you're driving.

Coming down from higher speed to a lower constant speed, or on slight downhills, try to stay in a higher gear than you normally would. You can often get away with it without lugging the engine, when you're just rolling along and the engine is very lightly loaded.
It'll work well for FE - until you need to accelerate again or have to deal with a slight incline, and the higher gear can't pull off the low rpm anymore so you'll need to change down 1 or even 2 gears.

Lets say I'm coasting in neutral at 30 mph, and need to accelerate because the streetlight turned green. Would I shift to the appropriate gear for that speed?

Shift into the appropriate gear for the speed you're doing.

If the speed is near the upper end of the speed range for a gear, switch to the higher gear right away - it'll be a lot smoother without feathering out the clutch for a long time.

Help the engine to get up to speed by rev-matching it with a bit of throttle while you're re-engaging the clutch.

And would going from neutral to 3rd, for example, damage the transmission?

It won't if you disengage the clutch fully - so make sure to push it in all the way, then shift into gear and smoothly re-engage the clutch.

At 30mph, you're probably OK to shift into 4th already.


A note on using the clutch :

Beginning stick-shifters have a tendency to use the clutch to control speed.
This is only done when manoeuvring at very low speeds in 1st and reverse, when a fully engaged clutch would give excessive speeds.

Other than that, the clutch is only briefly and smoothly used to get rolling, and to shift gears.

However, some hypermilers will use the clutch to bump-start their engine after coasting with the engine shut off . That's pretty advanced hypermiling.

Other than these conditions, the clutch should be either fully engaged, or fully disengaged. Clutch slippage = wear, and should be reduced to a minimum.


On a manual tranny, there's no slush box to compensate anything, and no slippage unless you use the clutch, so you have to be smooth with the expensive foot.

Train yourself to use the accelerator smoothly, so you can smoothly accelerate away from idle to higher rpm, then slow down smoothly to rolling in idle again without any jerking or bucking - all while staying in the same gear and without using the clutch.
Only when you can do that in 1st, are you really controlling your right foot