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

Its architecture is radically different
and can’t be retrofit into existing engines

Under no circumstances will the variable compression ratio (VCR) be an add-on technology, i.e. added onto a pre-existing engine without changing the core. VCR is intended for the engine’s internal power transmission system and concerns the most highly loaded parts of the engine. Hence, VCR can only lead to a new family of engines without any possibility of retrofitting a pre-existing family of engines.

VCR can only lead to a new family of engines without
any possibility of retrofitting pre-existing engines

MCE‑5 VCRi's architecture, weight, size and
vibro-acoustic emissions make it a
"transparent" engine for the integrator

As a result, someone who would like to apply VCR via an add-on technology would do better to give up on VCR as they are looking for something that does not exist and likely never will.

Does that mean we have to give up on VCR? Absolutely not. VCR will provide such decisive advantages that abandoning VCR will probably quickly become synonymous with loss of market share, decreased profitability and a technological lag that no other alternative could reasonably make up for. In the short or medium term, each carmaker must therefore have to make the effort to develop a family of VCR engines, which is not an insurmountable problem with the right technology.

In truth, it’s not important to know whether it’s possible to retrofit engines but rather whether it’s possible to retrofit vehicles. It is in fact essential that a VCR engine be able to meet the same service objective with the same engine size, with a similar weight, comparable integration constraints and similar vibro-acoustic emissions as those of the replaced engines. It would be unthinkable to build new cars because of an engine change.

Based on these criteria, the architecture, weight, overall dimensions and vibro-acoustic emissions of MCE‑5 VCRi make it a “transparent” engine for the integrator, who will see practically no difference between an MCE‑5 VCRi and an ordinary engine.