Change the narration: "I’ll clean the car tomorrow," Tim said to his father.

Tim told his father that he would clean the car tomorrow.

Tim told his father that he would clean the car the following day.

Tim said to his father that he will clean the car the following day.

None of these

Tim told his father that he would clean the car the following day.

"I’ll" becomes "he would" in reported speech.

"Tomorrow" changes to "the following day."