Opinion: The charm of large, naturally aspirated engines

Wait a minute. Is the large-capacity naturally aspirated engine dead? It certainly appears to be. Yeah, sure, Ferrari has an ace, and Lamborghini hasn’t put an end date on its large-capacity V12 yet, but look around elsewhere, and you certainly can’t find any. Sad.

This month, I had the privilege of getting behind the wheel of a fair number of large-capacity naturally aspirated engines. And boy, oh boy, did they feel special! Wide powerbands, a willingness to rev, and the best bit – no progressively running out of puff at higher revs. 

BMW’s N73-based 6.7-litre direct-injection V12 is epic by any measure; any yardstick. This engine that powers the Rolls-Royce Phantom VII makes huge urge at any speed – the direct injection making the huge 720Nm of torque peak earlier and sustain for long. Initial responses are deliciously direct. You squeeze gently, the Phantom slips forward effortlessly, like the car is suddenly weightless. A bit more boot and the massive urge comes flooding in, the big engine delivering effortless thrust that pins you back like a four-engine aircraft at take off. Clean, silent, impossibly smooth and crushingly quick, it’s a momentum machine.

The other large-capacity atmospheric icon I got behind the wheel of for the better part of a week is Merc’s M100 V8, the one that displaced 6.9 litres. It’s much more old school and basic, but it was not what I expected. Yeah, sure, with pistons the size of small buckets, the engine has plenty of reciprocating mass and, as expected, it is slow to respond. But the largest Merc engine ever and the first V8 is full of surprises. Once it gets going, it loves to rev. And there’s no strain as it spins faster, no gnashed teeth, no going red in the face, just smooth, cool composure and effortless sledgehammer-like thrust. Merc’s cost-no-object M100 V8 is so good, it still feels special.

The third is a 4.2-litre diesel. Now, naturally aspirated diesels are normally as agile as draught horses. These heavy engines with industrial internals take a lot to get moving; let Toyota engineers loose on the engine, though, and they will make sure it is as blunt an instrument as you can get; everything dialled down. Still, long pulls in the mid range prove that once the engine gets going, it is all but unstoppable, the rattle from under the bonnet smoothening up. It helps that it’s a smooth straight-six and that the gearing is long.

Question is, can hybridised large-capacity naturally aspirated engines make a comeback. Yes, they will, in time. Engine capacities may not quite be the same, and there will be plenty of electric boost, but as many supercar makers have shown, e-boost is just as good as turbo boost.