Cylinder deactivation issues in your 2018 Mazda CX-5 can affect fuel economy and create noticeable driveability symptoms. The Skyactiv-G 2.5L engine uses i-stop and cylinder deactivation technology that can develop problems.
Understanding CX-5 Cylinder Management
The 2018 CX-5's 2.5L Skyactiv-G engine uses cylinder deactivation during light load conditions to improve fuel economy. The system deactivates two cylinders by controlling valve operation, reducing pumping losses while maintaining sufficient power.
Cylinder Deactivation Operation
Under light throttle and steady speed, the system can deactivate cylinders 1 and 4. This operates through variable valve timing mechanisms rather than the lifter-based systems used by some manufacturers. The transitions should be seamless when functioning correctly.
Symptoms of Problems
Rough running during deactivation mode, vibration that correlates with highway cruising, fuel economy worse than expected, or check engine lights related to cylinder operation indicate system problems.
Different from Other Manufacturers
Mazda's system differs from GM's AFM or Chrysler's MDS. The Skyactiv approach uses different mechanisms, so issues and solutions differ from other cylinder deactivation systems.