ECO Mode - Right Hand Dial

[Chief inspector]

Certainly the what the eco ‘clock face’ represents is a mystery to me, all I can follow is keeping the needle no higher than the white dot, which just means a light throttle and not exceeding the speed limit by more than 2 mph.

Although as the speedometers in these cars over-read by 2mph, it means not exceeding the speed limit.

[Wizzpop]

Originally Posted by Chief inspector

Certainly the what the eco ‘clock face’ represents is a mystery to me, all I can follow is keeping the needle no higher than the white dot

I suspect it is measuring the inlet manifold pressure. We used to call it a vacuum gauge!

[Chief inspector]

Originally Posted by Wizzpop

I suspect it is measuring the inlet manifold pressure. We used to call it a vacuum gauge!

Not on a diesel!

[jaysmith60]

Originally Posted by Quacker

Don’t worry about coasting. It actually uses more fuel than if a gear was engaged, because on engine over-run all fuel is cut off, compared to coasting where enough fuel must be consumed to keep the engine idling.

This is a very valid point and it gave me much thought when I first read it. It is true that for a given length of time, the fuel used while coasting will be slightly higher than the fuel used by cruising without acceleration when gear engaged.

However consider two cars, one "coasting", and one "cruising" along the same route. The cruising car speed will decrease more if the gear is engaged than the coasting one (assuming flat or downhill) due to engine braking. After one minute, the while the coasting car may have used slightly more fuel, it will have travelled further and have higher steady speed. The extra fuel used to speed back up again/ travel the remaining distance in the car with gears engaged will outweigh any difference.

So when economy in litres/min, staying in gear will be optimal. But coasting would provide better mpg (or l/km).

....I think

[Giles1234]

Originally Posted by nu11eaf

The display is an economy meter, if you can keep the pointer below the eco indicator you are doing well, When you put gearbox in manual you are no longer in eco mode as you have control of revs and when you change gear so the car cannot change up or down for best economy and stop start is not active and aircon will go back to full function when in manual. You can have instant MPG at the bottom of the display as well as miles before tank empty, you have to set this up with the right hand steering buttons and tick the boxes, you can change other options there too.
Also when in eco mode the car will coast when you take foot off the accellerator going down hill etc and coasting is displayed at the bottom of the eco display, touching the brakes stops coasting and you have to use the accellerator again before it will re-activate.
I agree about the temperature gauge, I like to see that in my cars.

Thanks dude this is really helpful. I had not scrolled down that menu on the steering wheel passed the first 4 entries! I was shocked to see the instant mpg drop to 2.5mph when I put the boot down haha!

Question: What is TA? If TM is trip meter...

So basically, when in manual gearbox mode, you are not in eco mode but the RH meter is actually quite useful in helping drive economically. But when in auto gearbox mode, you are in eco mode but the meter is basically pointless, as there is nothing you can do to effect the efficiency of the car except to go slower!

[Wizzpop]

Originally Posted by Chief inspector

Not on a diesel!

Why not?
The vacuum gauge provides a means of testing intake manifold vacuum irrespective of the type of fuel. As both petrol and diesel cars are fuel injection now, the inlet manifold only has air flowing through. It will still have varying air pressure depending on throttle opening.

[Chief inspector]

Originally Posted by Wizzpop

Why not?
The vacuum gauge provides a means of testing intake manifold vacuum irrespective of the type of fuel. As both petrol and diesel cars are fuel injection now, the inlet manifold only has air flowing through. It will still have varying air pressure depending on throttle opening.

Any decent manifold vacuum is dependent on having a throttle, diesels dont have a throttle, thats why they have a vacuum pumps for servo’s. At wide open throttle, even petrols have little vacuum.

[Berkshirebob]

Originally Posted by Giles1234

Thanks dude this is really helpful. I had not scrolled down that menu on the steering wheel passed the first 4 entries! I was shocked to see the instant mpg drop to 2.5mph when I put the boot down haha!

Question: What is TA? If TM is trip meter...

So basically, when in manual gearbox mode, you are not in eco mode but the RH meter is actually quite useful in helping drive economically. But when in auto gearbox mode, you are in eco mode but the meter is basically pointless, as there is nothing you can do to effect the efficiency of the car except to go slower!

Both trip meters - TA (auto) resets itself after 4hrs (I think) with engine off.
TM (manual) - is the one you reset with the button on the end of the L/H stalk.

[MOzS90]

Originally Posted by jaysmith60

This is a very valid point and it gave me much thought when I first read it. It is true that for a given length of time, the fuel used while coasting will be slightly higher than the fuel used by cruising without acceleration when gear engaged.

However consider two cars, one "coasting", and one "cruising" along the same route. The cruising car speed will decrease more if the gear is engaged than the coasting one (assuming flat or downhill) due to engine braking. After one minute, the while the coasting car may have used slightly more fuel, it will have travelled further and have higher steady speed. The extra fuel used to speed back up again/ travel the remaining distance in the car with gears engaged will outweigh any difference.

So when economy in litres/min, staying in gear will be optimal. But coasting would provide better mpg (or l/km).

....I think

Exactly this. More fuel is used to accelerate back to cruising speed than actually rolling down a hill, gaining more speed then re-engaging cruise as you return to your set speed.

The other reason I take roundabouts as fast as I can using the racing line if the road is clear to keep the momentum going and not waste fuel re-accelerating to cruise speed.

It’s an art saving fuel!!!!

[nu11eaf]

Originally Posted by Giles1234

Thanks dude this is really helpful. I had not scrolled down that menu on the steering wheel passed the first 4 entries! I was shocked to see the instant mpg drop to 2.5mph when I put the boot down haha!

Question: What is TA? If TM is trip meter...

So basically, when in manual gearbox mode, you are not in eco mode but the RH meter is actually quite useful in helping drive economically. But when in auto gearbox mode, you are in eco mode but the meter is basically pointless, as there is nothing you can do to effect the efficiency of the car except to go slower!

The TM will add up all your trips upto I think 999 miles then start again, or until you reset it with a long press on the reset button on the end of the indicator/light stalk, I reset mine every time I fill my tank as a guide to how many miles I get from a tank full of fuel.
The TA records your daily accumulated mileage and as previously stated it will reset itself after several hour of engine shutdown, usually this will happen overnight.

Eco mode apart from driving with a light foot watching the eco meter to save fuel, putting it in eco mode puts the climate control into reduced limited use mode and uses stop/start if perameters are all ok and will adapt the gearbox to change gear at lower revs or change down sooner as well as throttle responce changes, and uses coasting. All designed to save fuel.
In reality, I have never noticed much difference. Apart from the windows steaming due to reduced climate control.