Would you say that the days of the internal combustion engine are numbered? After all, more manufacturers have either a hybrid engine option or offer an electric only drive on various models. Or, if you are the irreprissible Elon Musk and the company is Tesla motors, then you link your entire future to the fact that electric drive is as much a part of our present as it will be our future. If you were willing to think around the usual cause and effect relationship – somehow this phase of cheaper petroleum could very well be seen again in the future, when our demand for fossil fuels falls away because we are getting all the energy we need from renewable sources like the Sun, wind, tides and bio-mass.
However, that day isn’t today and we are still linked with the internal combustion engine, even when we want to be ‘green’. After all, the hybrid engine is part internal combustion. For the degree of integration that the IC engine has in our economy, you would think that it held this status from the beginning of time. But that’s not the case – the automobile was invented to run on steam, electricity and even burning fatty oils, but it was the discovery of the then cheap and wonderful supplies of petroleum in tar pits and marshes that began to change the source of fuel. Having effectively dealt the death blow to the world’s whale oil industry, petroleum latched on to the sutomobile and then branched out as the preferred source of motive energy along with coal (which was largely confined to ships due to its ‘bulky’ nature).
Today, more than a hundred years later, we are still fixated on the internal combustion engine, with both the pterol and diesel variants having their followers, although dieselgate has done much to switch public opinion further over to the side of petrol, especially for light vehicle use. Technology has allowed us to finehone the engineering so as to make the engine offer a better than 70% thermal efficiency, with diesel actually topping that. The battery and electric motor is still stuck way down in terms of efficiency although they are still seen as better than solar cells as a power source. But the problem we have with electric drive is in getting the cleanest electricity from the power station.
How about a cleaner, more efficient, more powerful version of the venerable internal combustion engine?
Infiniti has just announced their variable compression engine, that in effect changes the length of the piston stroke to change compression ratios, allowing the engine to switch from power to efficiency. Is it pathbreaking? Yes, it is. But it is only one of the suite of technologies out there, from cylinder on demand (that changes volume), variable turbocharging (that changes the boost pressure), variable cam adjustment, variable valve lift and timing and even variable injection that can switch between throttle body and cylinder in a flash. What engineers agree on is that the more options you have, the finer the control you have on the whole power and consumption equation and the better your engine.
As the computing power onboard a car leaps ahead of the curve, the car is not just able to plot its way through the world’s roads, compute the probability of accidents and calculate the best way to avoid or embrace a crash, it can also finetune the increased number of variables that a modern engine present, balancing the need of lower engine pressure with better efficiency.
The big if is finally just how reliable the latest variable compression technology is – in an engine environment the stresses are almost uncontrollable when you have mechanical linkages that need to flex and adjust. Other manufacturers have tried to address this before and failed. You definitely don’t want a link, bearing or joint breaking in the engine, it will most likely destroy the block. So does Infiniti have a magic answer that will prove more dependable than older technology? Only time will tell. In the meantime the engine may undergo other changes, like the ability to switch fuels mid-operation or be able to mix varying displacement cylinders on the same crankshaft. All of these are considered almost impossible – but why wouldn’t you try?