One of the things which intrigues me is the cost differentiation for manufacturing a 100bhp motor versus a 200hp unit.

Most EVs seem to have a healthy power rating so I presume there is not much difference in manufacturing costs.

While most of us here understand what it takes to make a more powerful ICE the wires and volts business is a bit of a dark art.

Similarly is a larger motor less efficient at a given speed than a less powerful unit?

An ICE car with a 200hp engine will generally use more fuel at 50mph than a 100hp one.

As most manufacturers do not shy away from fitting quite powerful motors to even moderately modest cars while still offering reasonable range it would appear that energy efficiency is not so tied to the ultimate capability of the power unit.

Well you learn something every day. I never new that the batteries had to be cooled in your EV. So there is something that could go wrong after all!! A quick google says that it is quite a complicated process. Does anyone know if the very large storage batteries that are linked to solar farms need cooling when they give up their energy to the grid?

Tesla has a very complex cooling system for the battery with plenty of bespoke components.

Unlike the Leaf mk1, which had no battery cooling system, making it very unrelaible in hot countries (apparently they have had loads of issues is Oz according to John Cadogan).

PHEVs are ICE cars so need conventional gearboxes - unless ICE is used to generate electricity which could drive motors directly.

I think the Defender is slightly different. I know it is hardly a technical publication, but the CAR Magazine (I think it's capitalised?) states as follows (not my use of 'interestingly' !

www.carmagazine.co.uk/car-reviews/land-rover/defen.../

"Interestingly, unlike the Evoque P300e where the engine drives the front and the e-motor drives the rear axle, the Defender's e-motor is sandwiched between the engine and the gearbox. Adam Southgate, vehicle dynamics senior manager for JLR, told us it the Defender's use of e-power is such as to not adulterate the off-road capabilities."

"Interestingly, because the e-motor is before the gearbox, you still feel gearchanges in e-mode and – something that's more of a downside – it also means you still have to wait for the gearbox to engage a gear when you stamp on the go pedal; no instant e-torque here from a standstill, but it more than makes up for it after cogs have been swapped."

I also read that it maintains four wheel drive in EV mode, and will go through the low-range gears as well. The amount of torque available in low range EV mode must be monumental.