I was quite keen on the idea of a PHEV, but I did a lot of research and, as others have said, the quoted figures, both for mpg and bhp, are highly misleading. The first thing to keep in mind is that, as a rule of thumb, the ‘all electric’ range is usually only around two-thirds to three-quarters of what is quoted. This was fairly common in most reviews of different PHEV’s and, as one reviewer said “accept that from the outset or you will be disappointed”. The electric range is also dependent upon charging the car fully after every use and switching the car into EV only mode (or equivalent) as the default is the EV auto mode which switches between electric and petrol depending on demand. In real world driving, the achieved mpg is significantly less than quoted as the electric range is so short. Most manufacturers quote mpg for PHEV’s of around 150-200 mpg, yet road tests seem to point to realistic figures of up to around 65 mpg, so you need to do the maths to work out if you will save money based on that sort of mpg and your annual mileage versus the very high AP’s. Also, keep in mind that electric isn’t free!
The next issue is that people get excited about the quoted bhp (power) figures but, yet again, these are misleading as they are the combined total of two separate engines that don’t always operate together. To take an example, if a PHEV is quoted as 250bhp, it may have a 150bhp petrol engine plus a 100bhp electric one. This means that if your aim is to minimise running costs and run almost exclusively on electric power for short journeys, you are driving a 100bhp car and not a 250bhp one. PHEV’s are also much heavier than their petrol / diesel equivalents, so power to weight ratio goes against them. Secondly, on longer journeys, when you run out of electric, you are driving a 150bhp petrol engine, yet lugging around a very heavy car, so performance and economy will be worse than a conventionally fuelled 1.5 litre car. The sweet spot is when you have a charged battery and it operates in unison with the petrol engine but, unlike a petrol or diesel car (where the quoted power output is available 100% of the time) you only get this in certain circumstances. If you keep the car fully charged and leave it in EV auto, you will get this performance most of the time but then, of course, you are using petrol so will get the more realistic mpg. Basically, you can’t have both!
PHEV’s are very popular with company car drivers, due to the much lower company car tax, but apparently many of these drivers never plug them in and run them solely on the petrol engines plus regenerative electricity. It’s basically a tax dodge. The reviews acknowledge this and also state that PHEV’s rarely stack up as a private purchase, as the extra purchase cost is more than you would save through lower running costs. As a Motability customer you have to do the maths, based upon realistic (not quoted) mpg, what your normal journeys are and how easy it is for you to fully charge after every use. And if you intend to run on almost exclusively electric power, keep in mind that you are not driving a particularly powerful car, unlike a full EV where the quoted bhp is available all of the time.