Don't have either of those but do have a Superb PHEV. Its big heavy car but probably better aerodynamically than any SUV.

There is an important thing to remember, the actual MPG you get depends on how often you charge and how long your journey's are.

If all our trips were below 30 miles we would use no petrol and the cost of electricity @ 9.5 p a unit would mean about £1 a charge. with petrol at £1.35 a litre (£6.14 a gallon) we would get 6.14 charges to a gallon thus 6.14 x 30 = 184 mpg.

When we go to the lodge in Scotland we set off with a full tank and a a full battery. We get no opportunity to charge during the week so once the electric is gone the car is driving like a normal self charging hybrid i.e. it recharges a bit on the over run and when braking. For 1,000 miles we normally average about 58 mpg which is better than the 52 ish we used to get form the previous manual 1.4 TSi Superb.

In the real world ours does a mixture of both, in 3 1/2 years its combined average (converting the cost of electric used to gallons + actual gallons) has been about 66 mpg.

Overall very happy with the figures but when I was working with a 30 mile round trip commute I would have been saving far more. 2 directors had Mitsubishi plug ins and never charged them, their saving was the low BIK payments.

Just compared an Astra phev to a petrol on one of the sites. The phev is £11 k more expensive but great on economy around town. On the motorway once the battery depletes the petrol is slightly more economical.