Well, we went through this with the introduction of unleaded petrol. Its impact on older cars and motorcycles resulted in the gradual disappearance of older run of the mill vehicles as their value fell below the economic costs of modifying cylinder heads to suit, and if the percentage of ethanol is going to be gradually increased to reduce emissions then more and more modern vehicles will be affected.
As I understand it petrol vehicles built from 1993-on should mostly be able to use E10 though they might not run as well as with 100% petrol but the ethanol could still affect seals in the injection systems and engines. I can foresee E15, maybe E20 (if that is feasible) leading to a further decline in petrol engine usability. That, and increasing taxes on internal combustion engine vehicles and their fuel and at least initially subsidising new electric vehicles will eventually reduce petrol and diesel vehicles to the level of specialist enthusiasts' vehicles.
There could be a compelling case for a scrappage scheme too. Perhaps the late 2020s and 2030s will be remembered for a great cull of obsolete technology as there was on the UK railway system with the end of steam. There are millions of them about, but how long before the cut off date in January 2030 for petrol and diesel production would their running costs be artificially increased enough to encourage the change to electric? There would be masses of them about after 2030 but would the high VED and cost of fuel make them too expensive to run? It would take a government with big balls and excellent organisation to do this, not been much evidence of these commodities to date. If they don't get it right, it could cause hardship for thousands, maybe millions. PLUS the biggie, the reduction of emissions which even the most reclusive troglodite petrolhead must by now realise is a priority.
And as for motorcycles, and as a lifelong motorcyclist it saddens me to say this, bikes nowadays have largely been relegated to the status of fine weather toys, with the resultant lack of investment in affordable daily transport either with petrol engines or electric. Electric scooters as town transport are a start, and building upwards from that base to produce usable affordable bikes with decent performance and range should follow, compared with the high performance short range offerings we are seeing at unaffordable limited production prices at present.
My interest in this is that I have a 1995 Honda NTV650P (model year 93-94 or 5 model) which I suppose just scrapes through the '93 barrier. It's in daily use. A proper old school Honda. It's my second one. I wondered what I was going to replace that one with, and the answer was, this one!
As for a replacement, petrol or otherwise, between whenever this needs replacing and 2030, I will be 78 by then so if I'm still functioning then, marvellous, otherwise it's all academic. At present there are no electric candidates.
Back to cars. Meh. Just a device to cart my bicycles about. I've got no emotional attachment to what might power it. My worry is that with the disappearance of cheap petrol and diesel cars the replacements are going to be out of my reach, and that of many others too.. Either because they are going to be too new to be affordable by myself and others, as a secondhand market needs time to build up and stabilise, or just too relatively less available than their predecessors.
There are going to be interesting times ahead.