The Toyota system doesn’t technically have a CVT transmission.

It uses a planetary gear system that is functionally equivalent to a CVT. The engine speed isn’t directly linked to the road speed so it can be optimized to balance how much ICE power goes to the wheels and how much goes to the electrical system, and vice-versa. Technically different, functionally it serves the same purpose.

The function of a CVT gearbox is only to vary the torque and speed of the wheels relative to the engine.

The purpose of the Toyota hybrid drive is to send energy where it’s best sent, and as a side effect this varies the ratio of road speed to ICE speed, so I reckon that it’s quite different. It just feels the same under many circumstances (but not all).

I’m well acquainted with how the system works, where I’m filling in the blanks is the relationship between charging the battery whilst cruising and throttling back. If you have a SoX lower than the target (something like 70% or 6 bars out of 8 on the display) and cruise at say 60mph it will give about 50mpg for a few minutes and then jump to 75 or so. It’s clearly stopped generating electricity at this point and list now be limiting engine speed the traditional way. The question is, is it doing this because the battery is effectively full and it has to, or just because it is now more efficient?

The fact that it generates whilst cruising at a cost of instantaneous economy suggests that it does this be wise the overall energy output (cruising energy +battery charring) is higher than simply waiting for regenerative braking to refill the battery.

I quite like the idea of towing an extra battery for longer journers.

Well sort of. I thought we could agree on 3 battery sizes and then swap them for a charged on at a service station. That solves the long journey problem and no charging point at home problem. It also solves the waisted battery problem. There is a risk i might buy a 200 mile range car and rarely use more than 15% of the battery. That battery would save more co2 split between more vehicles

Yeah I thought of that but it’s not really necessary when you can do 250 miles between charges now.

I’d quite like a caravan with extra batteries in it to offset the increased consumption.

Emissions Elsewhere……..

This is taken to extreme by the BMW i3, which has 155 profile 19″ tyres, super skinny, all in order to reduce rolling losses as much as possible

Front and rear tyres on an i3 are different – I was asked to check the size on one we have in storage, and I assumed they were the same size all round, but something made me check front and rear, and they’re different.
Still skinny, though.

Early i3’s have 155 all round, later cars have an asymetric set up with wider rears (and the “s” has 20mm bigger section tyres)