Over 95 percent in the world uses petrol and diesel combustion engines now and even by 2020, ninety percent still will be, that leaves only ten percent using alternatives.
Car’s that run on electric, hydrogen and biofuels have potential, and we’re working on alternatives to. But the solutions most car makers have come up with so far, either offer up the driving exhilaration of a couple of squirrels on a treadmill, or are so expensive they’re just not realistic for most people.
To really affect global fuel consumption and emissions right now, you have to use something the globe actually uses right now.
Rethink the combustion engine, make it better and accessible to everyone, and you make a difference, a big difference.
How big? Consider that current combustion engines waste about 70 percent of the fuel’s potential energy. That’s a lot of room for improvement.
Our overall goal was to get 15 percent better fuel economy and a 15 percent improvement in low midrange talk from the same engine, all on regular fuel.
Two enormous guerrillas stood in our way. The First was figuring out how to capture more energy from the fuel.
To achieve this, we knew we had to raise the compression ratio which gives this a bigger power stroke in the combustion chamber.
The higher the compression ratio, the more energy you get from the combustion. But a high compression ratio usually ends up causing knock, which is when the air/fuel mixture ignites too soon, because it’s too hot inside the Chamber, so we had to cool things off.
Using some huge engineering muscle we came up with innovative solutions to do just that. Like a high-pressure 6 hold direct fuel injector, that fires petrol into the cylinder in stages for more stable air/fuel mixture, and a little volcano like pocket in the piston that gives the early part of the explosion a place to go without heating up the top of the piston.
To get all the hot exhaust out without shooting into the other cylinders which only heats things up again, we added a longer exhaust manifold used in racecars called a header.
Everyday cars don’t use headers because of the emission problems they create, but our advanced direct injection system solved that issue too.
That’s how we got more energy from the fuel.
The second gorilla was making sure we weren’t losing any of those improvements on the way to the wheels. So we reduced friction inside the engine by a whopping thirty percent. How? by sweating every little detail.
We improved oil pump efficiency by 74 percent and water pump efficiency by 31 percent, reduced friction from the moving parts like the pistons, rods and crank shaft by 25 percent.
Reduced valve train friction by 54 percent, and even reduce the effort the engine exerts to suck in fresh air by 13 percent.
When it was all over, we had done what couldn’t be done, achieving more talk better, performance and higher efficiency.
Congratulations Rudolf Diesel, the engine you invented in 1893 has come a long way. No longer sootie clattering workhorses, today’s diesel engines are quiet, durable and cleaner than ever.
They’re also around 30 percent more fuel-efficient than comparable petrol engines, yet deliver much more talk and power.
With these improvements came compromises. To run their high combustion pressures, conventional diesels need heavy, industrial strength parts that sap driving performance. And cleaning up their nitrogen oxide emissions often requires costly aftertreatment systems.
So we saw a big opportunity to create more torque, better fuel economy, less weight and lower emissions.
First we dropped the compression ratio to the lowest in the world for a diesel, 14:1 this delays combustion by just half a millisecond, which is enough time for the air and fuel to mix more thoroughly, reducing hot spots of oxygen and fuel that would otherwise turn into pollutants.
Bingo, our combustion is so clean that we meet the toughest emission standards without an expensive nitrogen oxide aftertreatment system.
And while low compression would normally mean a loss in efficiency, we actually improved it, because our clean slate approach allows us to optimize the combustion timing which gives us a longer effected expansion stroke.
Another challenge with low compression diesels is getting ignition going when the engine is not warmed up, so we use ultra-high pressure piezo fuel injectors that are so fast and powerful they create a rich air fuel mixture that’s easier to ignite. Then, a patented variable valve lift system recycles hot exhaust gases back into the combustion chamber to quickly warm the engine up.
Best of all, our engines low compression ratio doesn’t require the usual heavy industrial grade parts. As a result the engines weight was slashed by 10 percent.
By using a lighter crank and pistons, and an aluminium block rather than cast iron. This allows us to build lighter, more balanced vehicles with much better handling.
Mechanical friction was also decreased, resulting in lower fuel consumption and an exceptionally high red line of 5200 rpm.
When we were done we, had created a beast with much more torque at low and high speeds, yet twenty percent lower fuel consumption than its predecessor.
The SKYACTIV-D 2.2 liter twin-turbo diesel, delivers the driving performance of a 4 litre V8, the cleanliness of the latest clean petrol engines, and the fuel economy a hybrid.
With such dramatic improvements, Mr Diesel himself might not recognize it, but no doubt, he’d love to drive it.