Nope not 88mph and back to the future but 88mpg from the new Golf mk7 Bluemotion thing. Now I know these aren't exactly 'real world' figures but pretty mental nonetheless:
"combined fuel consumption of 88.3 mpg on the combined cycle and CO2 emissions of just 85 g/km"
"With its 50-litre fuel tank and 88.3 mpg fuel consumption, the new Golf BlueMotion has a theoretical range of 970 miles. Assuming an average annual driving distance of 15,000 km (approx. 9,300 miles), most drivers will only have to refuel 10 times a year."