What gear to use for economy?

moonrakerz

The correct answer is that you drive in the gear that the car is "happiest" in.

If you are going downhill or on the level, 30mph in 5th is probably OK (depending on the ratios in your gear box). If you are going uphill at 30mph, 5th is just pointless, it just makes the engine labour and you will use even more fuel.

Listen to the car, it will tell you which gear you should be in !

iolanthe07

Get an automatic?

LandyAndy

greenman7 wrote: »

I agree it depends on the car you are driving and it's gearing, my 1998 1.25 petrol Ford Fiesta was very comfortable in 5th gear at 30mph, I used to return about 38mpg. In fact 5th seemed a very versatile gear. Since I have replaced this with a Citroen C3 1.4 diesel it labours and shudders for the most part in 5th gear at 30mph, so I drive differently in 4th gear. Now I return about 65mpg as it is a more efficient engine. For fuel economy I would drive in the highest gear possible.

Because the gearing in the Citroen is way higher due to the totally different torque characteristics of the two engines.

Inactive

The pressure you use with your right foot is more important than the actual gear you use.;)

Indout96

thescouselander wrote: »

I've never been in a car that drives well at 30 mph in 5th gear - generally 5th is too high for this speed and makes the engine labour - bad for fuel economy and bad for your engine.

I would have though the most efficient gear is the one that requires the least amount pressure on the accelerator pedal.

My Celica will happily drive along in 6th at 30mph (unless its a steep hill and will pull away smothly in that gear, our Saab would be OK in 5th but would not pull away that fast so I would use 4th. Most well maintained cars should be OK driving and pulling away from around 2K revs, but will need a "blast" every now and then to clean the plugs.
The type of petrol used will also help with hi-octane pulling from lower revs.

Pew_Pew_Pew_Lasers!

Try cycling up a hill in top gear. You won't be able to do it (unless you have very low gears).

Cars are no different.

Inactive

Pew_Pew_Pew_Lasers! wrote: »

Try cycling up a hill in top gear.

That will save on the fuel bills as well.;)

Nice_Username

Stick the clutch down and coast whenever you can. Saves me heaps of fuel.

kitchpoo

Nice_Username wrote: »

Stick the clutch down and coast whenever you can. Saves me heaps of fuel.

Not true in most cars now (most Euro4 anyway), as they shut fuel delivery in any gear when not accelerating, and actually uses more fuel to coast as the crankshaft has to be turned not under the motion of the driveshafts.

It also leaves the vehicle with little control, I wouldnt advise this as a method of saving fuel anymore.

More economy methods are here - http://www.moneysavingexpert.com/travel/cheaper-fuel

and here

(PDF) http://www.iam.org.uk/NR/rdonlyres/397E5739-15A1-4BC6-965F-5BFFEF427FAD/0/fac16001.pdf

and the AA

http://www.theaa.com/motoring_advice/fuels-and-environment/drive-smart.html (note the bit on Coasting)

AdrianHi

kitchpoo wrote: »

Not true in most cars now (most Euro4 anyway), as they shut fuel delivery in any gear when not accelerating, and actually uses more fuel to coast as the crankshaft has to be turned not under the motion of the driveshafts.

It also leaves the vehicle with little control, I wouldnt advise this as a method of saving fuel anymore.

More economy methods are here - http://www.moneysavingexpert.com/travel/cheaper-fuel

and here

(PDF) http://www.iam.org.uk/NR/rdonlyres/397E5739-15A1-4BC6-965F-5BFFEF427FAD/0/fac16001.pdf

and the AA

http://www.theaa.com/motoring_advice/fuels-and-environment/drive-smart.html (note the bit on Coasting)

Coasting to save fuel has not been true since cars started being built with computer controlled fuel injection instead of carburettors. So we are going back 20 years or more for most makes. The injection system will inject fuel to sto the car stalling or in response to accelerating input. Since moving along in gear keeps the engine turning it does not need to inject fuel.