Infiniti launching variable compression ratio engine in Paris

Infiniti will present a production-ready variable compression ratio engine, called VC-T, at the Paris motor show in late September.

The concept could improve internal combustion engines in several areas, reducing weight but also reducing fuel consumption by a significant margin, improving refinement and increasing performance.

It’s the result of more than 20 years of development at Infiniti. VC-T, for Variable Compression-Turbocharged, can raise or lower the stroke of the pistons allowing the compression ratio to vary between 8:1 and 14:1 – providing performance benefits at low compression and efficiency improvements at high compression.

The engine’s control logic electronics vary the compression ratio depending on the driving situation. An actuator arm works on a control shaft to change the position of a multi-link around the crankshaft, raising and lowering the height the piston can reach in the cylinder.

If not quite a Jekyll and Hyde situation, the engine should be able to provide a range between Jekyll and Hyde according to load, throttle position and other factors.

Infiniti calls it ‘a revolutionary next-step in optimising the efficiency of the internal combustion engine’ – though it’s also illustrative of the lengths manufacturers are now going to in an effort to extend the abilities of such engines, in light of tougher emissions regulations and customer performance demands.

With low-hanging fruit such as direct injection, turbocharging, efficient transmissions and more already pushed to their limits, improvements in combustion power are likely to come in ever more elaborate forms.

Infiniti will reveal further details of the VC-T engine at the Paris motor show on September 29.