Thanks, Ben. Yes, there are so many factors to take into account - and the whole landscape of the cars, their batteries, and above all the recharging/refuelling infrastructure, keeps changing. No problem for folks that switch for a flashy new show-off set of wheels every 2 years. But if you want the 'investment' to last, you're trying to plan for a future that neither politicians, industrialists or technologists have even got close to agreeing yet.

If I had a garage at home, I'd just install a charging point (with a government grant here), get a 100% EV, and bank on finding a motorway charging point part way along any (rare) long journey.

But that option doesn't exist now, and won't ever - it's physically and legally impossible where we live.

So maybe the old Betamax PHEV is the solution after all.