Partial deactivation of an internal combustion engine

A method, comprising:

• in response to a decrease in engine load below a threshold,
• selectively deactivating fueling of a second group of cylinders while maintaining a first group of cylinders active;
• then, deactivating exhaust valves of the second group of cylinders after completing an exhaust stroke while maintaining intake valves of the second group of cylinders active;
• after deactivating the exhaust valves, closing a throttle element in an intake line of the second group of cylinders;
• and
• during cylinder reactivation,
• fully opening the throttle element before reactivating the exhaust valves and resuming fueling of the second group of cylinders.

A method for an engine, comprising:

• in response to cylinder deactivation conditions being met,
• deactivating fuel to a second group of cylinders while maintaining fueling of a first group of cylinders;
• closing a throttle element coupled to an intake line of the second group of cylinders;
• and
• actuating a variable valve mechanism to deactivate exhaust valves of the second group of cylinders while maintaining intake valves active, wherein the throttle element is closed after deactivating the fuel, and the exhaust valves are deactivated before an exhaust stroke following the throttle element closing.

A method for an engine, comprising:

• in response to cylinder deactivation conditions being met,
• deactivating fuel to a second group of cylinders while maintaining fueling of a first group of cylinders;
• closing a throttle element coupled to an intake line of the second group of cylinders;
• and
• actuating a variable valve mechanism to deactivate exhaust valves of the second group of cylinders while maintaining intake valves active, wherein the exhaust valves are deactivated after an exhaust stroke following the fuel deactivation, and the throttle element is closed after the exhaust valves are deactivated.