60km/h - Are you in 4th or 5th?

[Blitzen]

4th for me...just easier that way.

[NickZ]

Get in the car and drive on a straight road with a constant incline. Set the trip computer to show the current fuel consumption, and then try cruising on 4th and 5th.

Especially on an incline, you will find 4th is actually more efficient than 5th gear, you have to put the pedal down more to maintain the speed as the car is out of its peak torque, and hence using more fuel. But this is not really important, the bad part about this is that, as said before, labouring your engine at low revs is going to cause you problems in the long run.

In saying that, I cruise at 65 - 70km/h in 5th, but if i need to accelerate or am going up a hill and finding i am doing any more than just touching the throttle, i drop it to 3rd or 4th and keep the revs above 2000.

[poloplayer]

How many revs should we be doing in cruising in any gear? And how low can we go before we shift down?

[Pumpe-Düse]

How many revs should we be doing in cruising in any gear? And how low can we go before we shift down?

My general rule, for cruising in any car, petrol or diesel, is...

5-sp manual-
40 & 50km/h = 3rd
60 & 70km/h = 4th
80+ = 5th

6-sp manual-
40 & 50km/h = 3rd
60 & 70km/h = 4th
80 & 90km/h = 5th
100 & 110km/h = 6th

This sort of driving has netted me some pretty decent fuel results in everything I've owned, so I'm not about to stop.

[Kiel_GTI]

see i prefer

1st 0-60
2nd 60-100

so on and so forth

[RhysQ]

see i prefer

1st 0-60
2nd 60-100

so on and so forth

thats the spirit!

[ACTGTI]

My experience has been that if the road is flat, you'll get better fuel economy from 5th gear than 4th at 60km/h. Driving from Palmerston in ACT to the airport at 5am I regularly average 6.1-6.2l/100kms, it's all fairly flat and most is done in 5th. I did this in 4th, it was more like 7l/100km.

Sure, if you need to put your foot down change to 4th (or 3rd). Otherwise 5th is just fine at 60.

You may also notice that when you slow down to a stop, if you coast (in neutral, i.e. not in gear), you are using more fuel than you would if you leave it in gear for as long as you can. I've never really understood why but it's true. All these things help for better fuel economy if that's what you're after.

[RhysQ]

My experience has been that if the road is flat, you'll get better fuel economy from 5th gear than 4th at 60km/h. Driving from Palmerston in ACT to the airport at 5am I regularly average 6.1-6.2l/100kms, it's all fairly flat and most is done in 5th. I did this in 4th, it was more like 7l/100km.

Sure, if you need to put your foot down change to 4th (or 3rd). Otherwise 5th is just fine at 60.

You may also notice that when you slow down to a stop, if you coast (in neutral, i.e. not in gear), you are using more fuel than you would if you leave it in gear for as long as you can. I've never really understood why but it's true. All these things help for better fuel economy if that's what you're after.

which brings us straight back to this post........

Just because the engine is making boost doesn't mean that it will use more fuel.. Boost should make the engine more efficient and therefore you would be able to use less throttle. ie, there should be no difference.

One thing you guys are forgetting is that labouring an engine like that (1500rpm in 5th..) is worse for it in a lot of cases than revving the snot out of it. Lower oil pressure, more blow by, it can fracture rods/pistons etc etc.

My advice would be to leave it in 4th. The difference in fuel economy would be VERY minimal, if at all noticable.

[Ben_GTI]

I usually do 63km/h in 5th (i know the speedo is out), but if I need to go up a hill its either 4th or 3rd. If I still lived in Brisbane there is no way I'd do 60 in 5th because it is slightly hilly to very hilly everywhere. But the northern and western sides of Melbourne is flatter than a 10 yr old.. errr... well flat.

I agree labouring an engine is bad, but if it is perfectly flat or even slightly downhill I don't consider that labour.

[ACTGTI]

I agree labouring an engine is bad, but if it is perfectly flat or even slightly downhill I don't consider that labour.

I agree, I don't consider cruising at 60km/h in 5th on a flat bit of road labouring the engine.

The engine is not under labour just because it's revving at 1500rpm in 5th, it's only labouring at the point where you put your foot down at 1500rpm in 5th which I don't do.