The petrol engine runs more than it used to

The petrol engine runs more than it used to

On a hybrid, the combustion engine starts more often or runs for longer than it previously did in comparable conditions, reducing electric-only operation and fuel economy.

What can cause it

• Cold weather, which makes the engine run to provide cabin heat and to warm the catalyst
• Reduced hybrid battery capacity with age, giving the system less electric reserve to work with
• A hybrid system fault limiting electric operation as a protective measure
• A change in driving pattern — more motorway, more climate load, heavier traffic

What to check first

1. Compare against the same season and route rather than against a summer baseline
2. Check for any hybrid system warning message
3. Note whether the change was gradual or sudden — sudden changes are more likely to be a fault than degradation
4. Have the hybrid battery health and system status checked

What this symptom does not tell you

An observation narrows the search; it does not identify which of the possible causes applies to your vehicle. Confirm the cause before any part is replaced — several of the causes above produce an identical symptom.