How tech could save the combustion engine

Car engines are expensive things. More so than ever these days, with all the anti-emissions, economy-boosting, performance-improving tech car makers are forced to bolt on. And as regulations tighten, it’s going to get worse.

But what if just a single engine, and maybe even a single gearbox, could work for every car in a manufacturer’s range? With performance scaling up and down thanks to the addition of different turbos and cheap-to-fit electrical assistance? That’s the dream of one enterprising British-based company.

Mahle Powertrain is a global business that emerged from the old Cosworth company. Its engineers are showcasing a clever Volkswagen GTI prototype, that has a unique turbo petrol engine aided by 48v mild hybrid tech – including a high-speed electric supercharger that supports the conventional turbocharger also fitted.

Called eSupercharged Downsizing Demonstrator, the figures are remarkable. This little 1.2-litre engine is claimed to produce 260bhp. That’s 216bhp per litre, way more than any supercar on sale, never mind conventional cars.

It also produces a diesel-like 232lb ft of torque from 1500rpm – and 80% of that comes in from just 1000rpm. As if all that wasn’t enough. Mahle is also claiming 57.5mpg when tested on the current European test cycle, which is 25% more than the current Golf GTI.

Incredible, no? Less incredible was our first attempt at driving it, when the eSupercharger broke. At least this proved the strength of the little turbo engine, which feels production-ready. A few weeks later, we tried again, and were astounded at how well it performed.

How good is it? Think of it as a micro-sized V6. It feels like a punchy, effortless large-capacity engine at low speeds, but also revs right through its range with strong, consistent power. Speed gathers relentlessly and it seems as flexible as a small car with a huge engine, rather than the more inflexible turbo feel of modern cars.

If all this sounds like an expensive pipe dream, think again. Mahle insists it’s all been developed with low cost of production in mind. The scalable add-on electric tech is affordable. The battery on mild hybrid versions will be a cheaper lead-carbon unit rather than lithium ion. Just two or three different turbocharger options would theoretically be needed.

The company is so ambitious, it even says just a single fuel type would be used – petrol, rather than diesel. Add-on electric-assist components would provide the scalable economy advantages and petrol instead of diesel would simplify the emissions control devices required.