You never plug in your PHEV! Presumably you rely on recovery when braking and use the engine to charge. That's expensive. You can charge a PHEV from a 13amp socket in about 6 to 7 hours.
Same for lots of company car users, don't bother charging but it's attraction is (or used to be) much reduced Benefit in Kind ££tax
You'd be surprised how much Manufacturers develop models and engine options to follow trends in BiK tax, this then effects retail buyers with limited choice as the Mfr ain't bothered about your tiny purchase volume
