Featured So don't warm up your car. Just go after 30sec.

The engine is running, but not contributing to propulsion. As you accelerate the engine sound remains steady, revs don't change. Again, this is just for the first few blocks of a cold start.

 

Excessive idling in this context (taxi, city traffic or other long waits) has more to do with thermal cycling of the engine, which can be as much as 50°F. This behavior is one of the clear differences between a 1.8 hybrid and a 1.8 conventional engine.

Toyota cannot enforce a prohibition against long idling or excessive city traffic but understands it is not good for the engine. About the only reasonable mitigation is to change the oil more frequently. When the hybrid system recognizes a long idle situation, it will cycle the engine more frequently, charging the hv battery minimally each time.

Many believe thermal cycling is a contributor to oil consumption and head gasket problems on these engines. Clearly, some gen4 engineering modifications focused on reducing cylinder wall temperature variations.