Is The Downsizing Of Engines Really A Good Thing?

A common phrase seems to be knocking around the mouths of petrolheads these days. The sacred words are: “There is no replacement for displacement”. Now obviously that phrase has been around for decades, but it has significantly gained in popularity from people protesting against the trend of downsizing engines.

The current M5 waves a goodbye to the V10 in favour of a V8

In case you aren’t aware, manufacturers these days are being faced with ever-tightening laws and regulations when it comes to their car’s engine performance in terms of tree hugging. These days the rules are so tight, just improving an engine won’t cut the mustard.

So the common solution is to downsize the displacement, but keeping up the power output by throwing in a turbocharger or a supercharger into the engine bay. For the most part, it has worked. Hatchbacks now commonly come equipped with turbo’d 1.4L engines (replacing the once common 1.6L naturally aspirated units), and now have theoretical fuel efficiency to get their diesel rivals hot at the collar.

But improved theoretical mileage improvement is only one side of the story. Petrolheads across the world are making themselves heard for a good reason. So let’s go over one or two key factors that they are pointing out against the new wave of the dinky engines:

Firstly, they make a point about lag. When you add a turbo to a car, the power band is always going to be altered, because a huge majority of turbos do not function at low revs, resulting in a power drop at these low revs. To get around this problem, you can keep your can in a sweet spot by keeping your revs up. But this leads me quite well into the next issue…

Nothing... Nothing... Nothing.. Arrrrrgh, the boost!

If you read any article about a downsized engine car, you’ll find a lot of them will mention that they got a much lower MPG figure than the official numbers suggest. This is because to keep these micro engine cars going at a decent lick of pace, as I have just mentioned, you have to keep the revs up which will see your numbers tumbling to depressing figures. For example, it’s very easy to take a 1.0L Ford Focus ‘EcoBoost’ and drop its MPG into the low 20’s.

Compare that to a diesel, and you’ll find the sooty fuel will win. A diesel has so much torque on offer, it gives you the option of going just about everywhere in sixth gear, meaning that your MPG will stay admirably high.

But let’s not get too pessimistic about these new motors. After all, they are here to stay whether we like them or not; even sporty divisions are getting hit. Just look at the new BMW M3, it has a blown straight six instead of that rev-happy V8, and are the journalists complaining that it’s a bad car? Of course they aren’t.

"This is a horrible car" - said no one ever. Except me.

And if you want to be really positive about this new trend, you could mention that a lot more three cylinder engines are being produced now (like the 1.5L unit in the new Mini Cooper). Why is that a good thing? Well if you have ever had a ride in a three-cylinder car, you would’ve noticed just how much they sound like a V6.