I've got a PHEV (a Kia Niro) - it's a brilliant vehicle - any local journeys can be done on pure electric power (up to about 30 miles round trip) and the equivalent economy for these is in the 180mpg range.
When I need to go further I manage the electric power to save it for urban/congested parts of the journey and let the petrol engine kick in for the rest. Even if I have to set off with an empty battery (eg if I'm away overnight with no charger available) it still turns in about 70mpg. The crucial thing for me is the total absence of 'range anxiety', as I live way out in the sticks and public chargers are a rare sight.
Most of my journeys are a mix of battery/petrol and (for example) a 100 mile round trip will use about 4 litres of petrol and one full charge of electricity - total cost about the same as a gallon of petrol - so 100mpg equivalent.
Anyone who thinks they'll get 180mpg all the time is kidding themselves (or only ever does 30 miles or so between chargings).
The salesman was very careful to explain all the figures (which are in the Kia brochures) - there certainly was no mis-selling.
I think The Graun and Which are effluent-stirring in search of a catchy headline - not very useful at all.