How Does Honda's VCM Tech Work? (And Can You Turn It Off?)

A long line of powertrain innovations over the years has helped Honda develop a reputation for building highly fuel-efficient cars. One of those innovations is VCM, or Variable Cylinder Management, which was introduced in 2005, and it has featured in Honda's V6 engines in various forms since then. VCM works by temporarily deactivating a number of cylinders when the car is cruising at a steady speed. 

In early implementations of the system, VCM shuts down one bank of cylinders, leaving the engine running on three cylinders. In order to make sure the deactivated cylinders can be quickly engaged if needed, the spark plug remains active even when the fuel supply is suspended.

A revised variation of the system, used on cars like the 2008-2012 Honda Accord, featured an additional mode that shut down two cylinders rather than three in certain driving situations. Later VCM-equipped engines, produced from 2013 onwards, scrapped this additional mode and reverted back to the original two-mode VCM. 

Alongside the Accord, a number of popular V6-powered Honda models have also featured VCM technology, including the Odyssey minivan, the Ridgeline pickup, and the brand's family-friendly pair of SUVs, the Passport and Pilot. A range of Acura models also feature the technology, including the current generation of the Acura MDX.

Honda does not offer a way to turn off VCM from the factory. However, several aftermarket devices exist to prevent VCM from functioning. They were designed in response to complaints from owners that VCM tech was causing excessive oil burning in older vehicles, as well as causing premature wear on certain components like the engine mounts. Several different devices are available, with some that claim to feature CARB compliance certificates. 

However, using one of these aftermarket devices to disable VCM will come with some downsides, including a drop in fuel economy. Whether or not you should consider using an aftermarket device is down to personal preference. The safest way to avoid having to deal with the potential pitfalls of VCM is to simply avoid buying a Honda fitted with the technology altogether — after all, there are plenty of reliable Honda models that don't include VCM.