My car has a similar display option showing when the motor is helping and when the battery is charging etc, bit of a novelty really, I found it interesting for about ten minutes, I just let it all do it's thing without me monitoring it.

I agree. My Jazz hybrid has the option to show an animated schematic showing how the power is flowing, but after seeing it briefly I've not really bothered to look at it again. The instrument panel has an indicator that shows when you are in pure EV mode or if the ICE is running and there is a column of LED segments to show the state of charge of the HV battery. I might give these an occasional glance, but it's very much the case of letting the car get on with it and just driving as normal.

I find one of the most baffling part of driving a hybrid is to interpret the HSI (Hybrid System Indicator) gauge. This example is from Toyota but all hybrids have similar HSI.

[1] Why do we need a gauge for this? Drivers know when they are accelerating or decelerating and speedometer shows this already (speeding going down vs up).

You could also question why you need a rev counter in an automatic car. Or why you need display showing which radio station you are listening to (it could show you once when you switch on the ignition, or if you change station, then remain blank)

Or by the same argument, you could also question why a car has auto wipers or lights as drivers also know (or should!) when it is raining or getting dark.

In a self charging hybrid, invariably the best policy is just to let the car do its own thing. In a PHEV (with a decent electric only range), it might be a good idea (on a longer journey) to 'save' the battery power for going through a town or city. Otherwise again, just leave the car to get on with it.

I’d suspect drivers would find a tachometer (rev counter) a little off-putting on a hybrid, since you’d see the ICE working at a higher engine speed than they’d normally utilise. It’s working best at peak torque, and held there by the CVT, to provide maximum efficiency.

Yes, a tachometer would not be very useful. I've noticed since it's got a bit colder that when I start the Jazz the ICE starts immediately and runs at a very high tick-over for several minutes while I am manoeuvring very slowly out of the car park and out towards the main road. Once the engine has warmed up a bit, the engine revs drop, but still bear no relation to road speed.

However, a couple of weeks ago I decided to see what happens when you push the accelerator pedal to the floor while going up a fairly steep hill. The engine revs immediately jumped to a very high (and noisy) level, but as the car built up speed the transmission did about 4 or 5 simulated 'gear changes' with the engine revs dropping a bit at each 'change'. The transmission only has fixed ratio gears and there is no CVT belt & pulley system so the 'gear changes' can only be the system changing the ICE's revs in steps. I wonder if there is a practical reason for doing this or if it's just done for effect?

We have a CR-V hybrid which doesn't faff around with pretend gear changes. The engine revs just rise and fall like your Jazz, but the transmission just works seamlessly, which is actually one of the nicest features of the car. Can't imagine there is any technical reason for your "gear changes".

Most of the time the Jazz doesn't faff around either. It was just on this one occasion where I kept my foot flat on the floor, going up hill for about a mile (which is something I don't normally do).

Yes, a tachometer would not be very useful. I've noticed since it's got a bit colder that when I start the Jazz the ICE starts immediately and runs at a very high tick-over for several minutes while I am manoeuvring very slowly out of the car park and out towards the main road. Once the engine has warmed up a bit, the engine revs drop, but still bear no relation to road speed.

However, a couple of weeks ago I decided to see what happens when you push the accelerator pedal to the floor while going up a fairly steep hill. The engine revs immediately jumped to a very high (and noisy) level, but as the car built up speed the transmission did about 4 or 5 simulated 'gear changes' with the engine revs dropping a bit at each 'change'. The transmission only has fixed ratio gears and there is no CVT belt & pulley system so the 'gear changes' can only be the system changing the ICE's revs in steps. I wonder if there is a practical reason for doing this or if it's just done for effect?

We had a Jazz CVT and that also had no fixed gears. But the CVT is programmed to behave and sound like a DCT or a quick witted T/C auto. My assumption for the reason is to try and appease the CVT haters (mainly motoring journo's and folk who haven't actually driven a decent one) who go on about the 'mooing' noise on a traditional CVT, presumably the same would apply to your hybrid.

But ours was also surprisingly rapid if the throttle was floored and certainly dispelled the 'all noise and no action' labels from CVT haters. When we got the car, I was a little wary the first time a overtook a truck on a single carriageway road, but I needn't have been!.

"""I've found in practice that the best thing is to just get in and drive and pay little heed to what the ICE is doing. Its primary function in the system is to work as a generator, with occasional tractive assistance. Just concentrating on accelerating and decelerating gently and leaving the system to its own devices yields the best results.""

Sounds like driving an ICE on the famous economy runs to extract the maximum MPG. But what is really happening to the hybrid system when driven in a typical spirited way. i.e. foot down and hard braking? Can you tell if the battery will still give you a good range or is it helping the ICE to achieve good performance or indeed is the battery not playing a part but saving itself for little right foot input?

Maintaining momentum, as in any car, is key - not having to accelerate as much back up to speed.

Many drivers don't realise this; as they accelerate hard up to traffic lights and stop, whilst the more attentive driver will take their foot off the accelerator and coast/slow down, in anticipation of lights changing, so maintaining momentum.

Most eople buy cars because they need a car. Enjoyment for most is either secondary or a function of cost, reliability, brand perceptions etc.

Getting maximun MPG or miles per KWH is not about cost saving (it may be for some) but a simple "game" played to get the best score. Like getting maximum points on "shoot 'em up" or doing your standard daily jog a couple of seconds faster. No one else cares!

Enjoyment is different for different folk. For some it is driving to the max, subject only to speedcams. For others the goal may be smoothness - having passengers sleep whilst I am driving confirms my personal belief in qualities of anticipation, judgement, reading the road.

That one mode uses a lot more fuel is unimportant. The difference between ~40 and ~50 mpg may be just £5 a week - less than the cost of two coffees or a pnt of beer.