AFTER THE (BATTERY-ELECTRIC) BOMB
With the arrival of Tesla’s mass-market electric car, the Model 3, the headlines have been awash with proclamations about the imminent death of the internal combustion engine. But as AutoMate’s Harrison Boudakin reports, the fuel-fed, piston-driven miracle of the modern motoring age isn’t about to give up without a fight
Just one month before he would test-launch the most powerful nuclear weapon in American history, Admiral William Blandy remarked, “it is apparent that warfare, perhaps civilisation itself, has been brought to a crossroads by this revolutionary bomb.”
He was right: a technological masterstroke, years in the making, would soon come to fruition in a way that would completely re-chart the course of global conflict. The rule books on war were about to be re-written, forever.
Fast forward 70 years, and it appears that the course of global automotivity now stands at a similarly-powerful crossroad. Having enjoyed more than a century as the unchallenged king of motoring, the internal combustion engine must now confront the arrival of a new technological reality.
Because in 2017, the battery-electric car is no longer just a fantasy – thanks to a series of critical disruptions in the automotive universe, it is now rapidly emerging as a legitimate, credible and even desirable alternative to petrol and diesel power. In response, the internal combustion engine is being re-engineered and hit with a dose of superlative technology, to help it blend power and efficiency in ways hitherto unseen in production cars.
The result is that the global automotive industry is engaged in an all-consuming, 21st century arms race, as the dropping of the electric car bomb threatens the supremacy of established engineering truisms, and forces the internal combustion engine to up its game.
Diesel’s downfall re-sets the compass back towards petrol power
Of all the seismic events on the road to war between the electric car and the internal combustion engine, the explosive Volkswagen Dieselgate scandal was surely one of the most earth-shattering. More than anything else, the revelations of September 2015 changed the way we looked at the fuel that was once touted as the keeper of internal combustion’s environmental conscience.
Not only has diesel’s reputation been left in tatters, but it has also become painfully apparent that the cost of engineering future diesel engines to meet the next-generation of environmental legislation will eventually become unsustainable. As a result, we have witnessed a remarkable upsurge in innovation, as automakers shift their priorities back towards extending the staying power of the petrol engine.
And without question, one car now stands head and shoulders above the rest when it comes to pushing the boundaries of petroleum propulsion: the 2018 Mercedes-Benz S500. More than anything else, the engine in this car offers us a fully-fledged glimpse into the immediate future of internal combustion, and in the short-term at least, that future looks as though it will burn very brightly indeed.
Ironically, though, as automakers stare down the imminent arrival of the mass-market electric car, it’s actually a smattering of electrons that help make this German power-plant such an absolute game-changer. What starts out in life as a box-fresh, inline six-cylinder motor, has been garnished with a whole welter of efficiency-enhancing electric ancillaries, which – when you put them together – present a blueprint for the next decade of petrol engine design.
Indeed, an X-ray of the M256’s technical constitution reveals a motor laced with genuine mechanical ingenuity. For instance, because the water pump and the air-conditioning compressor are now electric, M256 no longer needs any drive belts whatsoever. Moving down the drivetrain, you’ll find an electric motor wrapped around the crankshaft between the engine and the transmission. This is what Merc calls the Integrated Starter Generator (ISG), and it essentially functions as an alternator, a starter motor and a sort of ‘e-boost’, all in one. Finally, nestled inside
the engine itself is both a conventional, gas-driven turbocharger, and an electrically-driven supercharger.
Complicated? Oh ja. Well, here’s how it actually works.
When you accelerate from a dead-stop, the ISG begins proceedings by spitting a zap of torque directly at the wheels, giving an instant response to the throttle. Simultaneously, the electric supercharger (which has no lag) is already providing boost to the petrol engine, and it does this until the revs are high enough for the conventional turbo to be up and running. Even then, the electric supercharger will continue assisting when the turbo is off-boost in certain mid-range situations; and just to be 100 percent sure that there’s thrust aplenty, the ISG will occasionally throw in some extra electrons, if it senses even the slightest hint of a torque deficit. Remarkable, isn’t it?
And we’re not finished yet. Yachting enthusiasts will be keen to observe the S500’s ‘sailing’ function, which will cut the petrol engine altogether in light-load, cruising conditions. It can do this because the ISG is used to keep the transmission spinning along gently in gear; not only that, but the ISG will also restart the petrol engine in complete silence when more power is called for.
Truly, if this powertrain weren’t German, we’d probably call it witchcraft.
Where there’s a spark, there’s fire. Or perhaps not?
So, it seems that by whirring the petrol engine to new heights of refined efficiency, with their ‘mild-hybridising’ strategy, Mercedes has found themselves right at the vanguard of internal combustion engined-progress. But Benz are not alone on this ship called progress: Mazda is now touting a new engineering breakthrough that could rather substantially re-cast the mould of the traditional petrol engine.
It’s true to say that in recent times, the Hiroshima-based automaker has been a champion of slightly contrarian engineering solutions. While the rest of the world downsized their engines and turned en masse to turbocharging, Mazda persisted with natural aspiration in all but their largest model. Instead, their current range of Skyactiv-G engines use ultra-high compression ratios and an innovative 4-2-1 exhaust set-up, to achieve levels of efficiency (if not torque) that rival the best turbocharged units out of Europe.
One can argue that Mazda have so far been successful in their cause: it’s well-reported that the Skyactiv-G engines have been exceptionally reliable in the real world, and certainly less fragile than their occasionally more highly-strung turbo rivals.
But never a company to rest on its laurels, Mazda is now on the cusp of advancing the game one step further, with what it has dubbed the Skyactiv-X engine generation. Set to launch in 2019, Skyactiv-X will in fact be the world’s first commercial application of something called Homogenous Charge Compression Ignition; or to put it another way, these will be petrol engines with the ability to act, in certain situations, like a diesel engine.
Intriguingly, HCCI is not new technology. Automakers have spent years tinkering with the idea of running a petrol motor sans spark plugs, but they’ve faced some stiff headwinds in the form of narrow powerbands and intolerably-high emissions. Now though, Mazda claims to have cracked the HCCI nut, and they’re ready to bring it to market.
To reduce it to its essence: Mazda have designed an engine, which – under low-to-moderate loads – will pressurise the air-fuel mixture, and then use the heat of that compression to create a detonation. In doing so, Mazda negates the need for a spark-plug, and gifts the petrol engine with diesel-like levels of low-down torque and fuel efficiency.
Unlike a diesel, though, which tends to run out of puff at higher revs, Mazda’s Skyactiv-G engines will use a spark plug during moments when maximum thrust is required. So, what we have here then is an engine that purports to be everything to everyone: diesel-like cruising efficiency, without any of diesel’s dirty emissions, and matched with the high-rev zing of a zesty Mazda petrol unit. If compromise is an art, this could be an effort worthy of van Gogh.
Approaching the crossroads
But more than anything, this technology – like the tech in Merc’s new S500 – proves a startling point.
Sure, the arrival of mass-market electric cars like Tesla’s Model 3 presents a grave and existential challenge to the traditional internal combustion engine. As the battery electric vehicle has become a simultaneously more desirable and practical reality for millions, we are rapidly approaching the crossroads, where the dominance of the petrol and diesel engine will be usurped by a wave of investment and commercial interest from established automakers, dedicated to bringing the world their own mass-market electric cars.
Without question, the electric car bomb has now been dropped, and soon enough, its aftershocks will change the face of global automotivity permanently.
And yet… as can be deduced very clearly from the efforts of Mercedes, Mazda and others, it would be absolutely foolish to assume that the internal combustion engine, in any way, will be allowed to vanquish its mantle without one hell of a decent fight.
Written by AutoMate Training – a world’s leading provider of online automotive training. Visit www.automatetraining.com for your free 14-day trial.