Infiniti's variable-compression engine offers diesel efficiency with petrol power
The company claims it's production ready, but it's not slated to appear in any production car just yet.

For the longest time, an engine's compression ratio has been a fixed value, but Infiniti's innovative VC-Turbo is set to change all that.
Using a complicated system of links buried deep within the engine block, it's able to change the piston's stroke, thereby varying compression ratio. It changes the ratio based on a number of inputs, and it picks a suitable ratio on the fly. It's able to change compression between 8.0:1 and 14.0:1.
The benefits are numerous. By running a low compression ratio, the engine's power output can increase, whereas a higher compression ratio can be used for efficiency. Switching between the two can bring both benefits to the same engine. That should help keep the internal combustion engine relevant for a little longer in the face of competition from electrification and hybrid drivetrains.
Infiniti believes the VC-Turbo will produce 27 percent greater fuel efficiency than a similarly capable V6 engine, despite being down two cylinders. The automaker is targeting a power output of 268 horsepower and 288 pound-feet of torque.
At the moment, it's only available as a four-cylinder, so it may not be any use to larger SUVs and vehicles that require a bit more thrust. Regardless, it's a hell of an achievement, even if it seems like a bit of witchcraft, and it will be interesting to see the engine arrive in Infiniti's vehicles in 2018.