Driving Economically.

surfsister

I really just wanted someone to answer the question. i thought this was a car thread not a nitpicking one. Or am I wasting my time here.

alastairq

surfsister wrote: »

I really just wanted someone to answer the question. i thought this was a car thread not a nitpicking one. Or am I wasting my time here.

That is a possibility?

I take it, one question is regarding whether to change gear into 4th or 5th 'early?'

There is no standard answer to that one.... as has been posted before.
Much depends on the 'power characteristics' of your car's engine, and how the driver 'uses' the gas pedal.....[amongst other things].

As a suggestion only.... try listening to your engine as you increase your speed, to see if it sounds as though it is either [1] labouring, ie 'grumbling', because you have too high a gear with too low revs, or [2] if the engine's revs are quite high [ie, to low a gear, giving too high revs]

the above may well give you...as a driver, a 'gut-feeling' as to whether the gear for the speed feels 'right'..

Try not to 'accelerate'' to your intended 'cruising' speed in 5th, if that speed is to be under .....[for example,] about 50mph???

Once your intended speed has been achieved, then use 5th...

Try to accelerate as gently as possible.......rather than rushing up to your intended speed?

On dual carriageways and motorways......try simply cruising at a speed on or around 60mph instead of trying to achieve the speed limit....?

[Feel free to use a quick burst up to the speed limit for overtaking, etc.....then once well ahead, ease back to your cruising speed?]

Make more use of the left [driving] lane as well...? [otherwise we'll upset regular contributors on this forum?]

Delivery_Driver

surfsister wrote: »

I really just wanted someone to answer the question. i thought this was a car thread not a nitpicking one. Or am I wasting my time here.

It's been answered as well as you could expect without us driving your car to see for ourselves.

Lum

Also, that was a really funny typo

Dave_C_2

The OP missed several important points as detailed at the start of this expert advice.

Dave

alastairq

Dave_C wrote: »

The OP missed several important points as detailed at the start of this expert advice.

Dave

it would be helpful if the points missed were in fact pointed out?

Then we could have a compendium of advice?

[feel free to challenge the AA and its assertions, however. In the end, they, too, often only supply opinion]

2010

Change up earlier: don't labour the engine but try changing up at an engine speed of around 2,000 rpm in a diesel car or around 2,500 rpm in a petrol car. This can make such a difference that all cars in the future are likely to be fitted with a 'Gear Shift indicator' light to show the most efficient gear change points.


A lot of newer cars now have this feature.
I always used to wait until about 50mph to change from 4th to 5th, but my latest car indicates about 40mph is correct.
Takes a bit of getting used to.

almillar

surfsister - there isn't one speed that all cars are most economical at. There also isn't a time when all cars should go up into top gear. It depends on type of engine (petrol/diesel just for starters), the gear ratios, drag, and of course the way you're trying to drive.
For example, if you're trying to merge onto a motorway, you should use the revs more and stay in 4th to accelerate, instead of changing early into 5th, and not getting the power. But if you're travelling at, I guess, a constant 50mph on a flat road, you should be in 5th instead of 4th, where the engine would be spinning unnecessarily fast.
There are only general tips, and you need to use your own judgement for your own car.

JimmyTheWig

Can any of this be applied to automatics?

alastairq

JimmyTheWig wrote: »

Can any of this be applied to automatics?

In my experience [of old-technology autos, especially] , they can be controlled by the driver.

However, the control exercised by the driver [concerning gear usage] is really coming at the issue from entirely another angle, compared to the process used in a manual gearbox.

On car autos [of my experience] there would be a 'kickdown' and a 'hold', available to the driver.

The kickdown facility enables the driver to acquire a lower gear ratio.

The 'hold' facility allows the driver to prevent or delay an upward gear change.


However, older types of car autos were limited in the number of gears available [typically, 3 gears up to 20 years ago].

[Nowadays, auto boxes have as many gears as a manual box.]

Thus, in days past, manufacturers tended to opt for a lower final drive ratio to offset a tendency for slower acceleration due to having fewer 'optimal;' gear ratios.

This meant higher engine revs at a given cruising speed...hence, higher fuel consumption.

Nowadays, software is available to allow an auto box to be in the optimum gear for fuel consumption.


My present-day experience concerns 6 speed ZFs in large [old, as it happens] lorries....and I point out that, unlike manual gearboxes, whose weakness is the driver....these autos do not allow the usual gearbox mistakes...ie, too low a gear for the road speed. or too high a gear for the road speed.
Thus, if the driver operates the kickdown, and it doesn't work, then that's because the vehicle is already moving too fast fro the next gear down.



So, after all that........it is possible to delay the upward gearchange [using the 'hold' facility], if the driver wants more speed from a given gear.