MCE-5 VCRi: Pushing back the fuel consumption reduction limits

It’s competing with other technologies

This statement is untrue: MCE‑5 VCRi is not competing with the other technologies, it complements them. In most cases it “boosts” their efficiency. Of course, the gains made by MCE‑5 VCRi technology do not purely and simply add on to those of GDI, turbo or VVTs. We can’t just add up the gains that each technology provides when taken alone and added to a basic naturally-aspirated engine: we would quickly come up with an engine that has negative fuel consumption. We have to see what leverage MCE‑5 VCRi has over different strategies when it’s combined with other technologies.

Each case has an optimum combination of MCE‑5
VCRi with other available technologies, which
leads to the best compromise between
obtained result and overall cost

We generally see that the effects produced by different existing technologies can either complete each other or “eat” each other up. Hence, in some cases MCE 5 VCRi must be used to replace other technologies and in other cases in must be used in combination with them. For example, a VVL system (Variable Valve Lift) reduces pumping losses, as do downsizing, downspeeding, lean mixtures, hybrids or continuously variable transmissions. Consequently, should VVL be planned for a hard downsized engine or one equipped with an advanced transmission? The question is worth raising since there is a gain that subsists when we pile on technologies. The problem is that we also pile on costs to the detriment of the final cost/benefit ratio. There lies the real challenge and thus, the optimization of the technological mix to be applied to each engine is based on a single criterion, which is maximum energy efficiency.

The aim is sometimes to find the minimum level of fuel consumption without worrying about the cost. This is rare and applies to high-end vehicles that put forward a “green-tech” image. Most often, the aim is to reach the cost/benefit ratio most in line with the present context or that of a more or less distant future. In this case, the profitability threshold for each gram of CO2/km eliminated is determined according to the tax penalties on CO2 emissions and the fuel price at the pump. A final case concerns low-cost vehicles for which the main criterion remains the absolute cost price. The technological mix chosen for these vehicles must have the lowest possible cost/benefit ratio.

In this context, MCE‑5 VCRi is a fabulous energy efficiency and economic optimization tool, in cooperation with the other technologies. For example, the most profitable engine for very small cars will be a 3-cylinder MPFI MCE‑5 VCRi engine with double-VVT and an MCE‑5 integrated compressor (under development). This type of engine will be extremely energy efficient, inexpensive and simple to integrate, with a capacity of 600 to 900 cc. For more powerful MCE‑5 VCRi engines, GDI is preferable to MPFI and two turbochargers should be planned to reach the best overall energy performance. In addition to these combinations adapted to each type of vehicle and performance, MCE‑5 VCRi will enable a wide variety of optimizations and cost reductions. For example, it will be possible to reduce the content of precious metals in the catalytic converters or the size of the starter. Another example of savings is that it won’t be necessary to plan for elaborate noise damping systems, as are required for Diesel engines.

In conclusion, MCE‑5 VCRi is not competing against any existing or planned technologies. On the contrary, it has real advantages allowing it to best cooperate with these technologies and to become an essential part of the technological mix applied to future IC engines, along with gasoline direct injection, supercharging and variable valve timing.