And yet even the least economical car here will top 80mpg – on that 30-mile town and trunk road test route, admittedly, and only after a full charge. It’s the 330e that props up the order – predictably, given that it has the least capacious high voltage drive battery here and the most powerful combustion engine. Even so, at least to this tester’s 20th century mind, 80.4mpg still seems like a pretty sensational result to get from your 249bhp BMW 3 Series on the way to work.
That’s particularly true when you consider that our third and second most economical plug-in hybrids returned little better than the BMW. The Passat GTE Estate narrowly pipped the 330e, returning an indicated 81.7mpg – and the A3 e-tron narrowly pipped both, at 86.5mpg. All three cars use fairly compact turbocharged four-cylinder petrol engines, of course, and all use an electric motor that drives through the same gearbox as that petrol engine, so similar economy is to be expected. The Audi’s result proves that a relatively low overall kerb weight can still be an important advantage to a car like this. The Volkswagen’s figure indicates that sophisticated driving controls can also make a difference, because the Passat offers you easier and finer control over the electric motor’s freewheeling and battery regen settings than any of its opponents.
But now get this: it’s actually the oldest car in the field, with an ageing five-cylinder diesel engine, that’ll do the most to save you money at the pump. The V60 brings not only the biggest drive battery to this test but also a direct-drive, stand-alone transmission for its electric motor, which outputs to the rear wheels. That means the V60 feels more like a pure EV than anything else on test, responding more instantly to the accelerator pedal around town and running more efficiently at urban speeds, you suspect, than it might if its electric motor drove through a conventional gearbox. The V60 returned an indicated 153.8mpg on our 30-mile test route, almost doubling the result of the next best car here. Quite a result.
You might expect the same order of merit to be repeated when ranking these cars for zero-emissions cruising range, which we assessed as part of the same 30-mile test – the first 15 miles of which were driven on the urban roads of greater west London. And yet it wasn’t – not quite. The car with the least battery range proved to be the one with the smallest drive battery (7.6kWh): the 330e, which managed 13 miles before the piston engine kicked in. The one with the greatest range also had the biggest drive battery (11.2kWh): the V60, which ran for 23 miles. But the middle order of the Audi and VW, as proven on test economy, was reversed on electric range, the A3 running for 14 miles on battery power alone and the Passat for 17 miles.
Before we move on, a quick mention of combustion-engine-only touring fuel economy, which will matter most to those who plump for a PHEV for the tax advantages, won’t bother to charge it frequently and do bigger mileages than our testing has thus far allowed for. If that sounds like you, don’t worry: we expect you’ll be in plentiful company. The Volvo tops this order again, returning 50.1mpg at a 70mph motorway cruise under piston power alone, followed by the Audi (47.9mpg), the BMW (44.6mpg) and the VW (42.2mpg). So even the worst car in the field isn’t far off what a like-for-like economy diesel will return.
BEYOND THE FIGURES
Apologies if you’ve gone a bit number blind. At least we’ve answered the pressing fuel economy question and proved that, in just about every respect, the V60 Twin Engine puts its electrified powertrain to best use if real-world fuel economy and reduced emissions are your chief priorities.