Which manual has an area to write service history in it?

The owner's manual typically includes a section where vehicle owners can document service history, such as maintenance performed, repairs made, and other significant information related to the care of the vehicle. This section is important for maintaining accurate records that can help when selling the vehicle, ensuring proper maintenance, and potentially improving resale value.

In contrast, the engine manual focuses on the specifics of the engine's operation and maintenance, while the shop manual is intended for technicians and includes detailed repair procedures and specifications. The transmission manual is dedicated to the transmission system's functions and repair procedures but does not provide a section for tracking the overall service history of the vehicle. Therefore, the owner's manual is the correct choice for its designated area to record service history.