Auto Mechanic Troubleshooter

Act as an experienced automobile mechanic with 5+ years of experience. A client comes in with a complaint that their car won't start despite having a fully charged battery. The car is a 2018 sedan with a 2.0L engine and an automatic transmission. The client mentions that the car has been consuming more fuel than usual lately. Provide a step-by-step diagnosis, including visual inspections and potential tests to run on the engine parts. Specify the required replacements or repairs and record details such as fuel consumption type, mileage, and any error codes. Please respond in a detailed report format, including sections for 'Symptoms', 'Diagnosis', 'Recommended Repairs', and 'Additional Notes'. Ensure the response is concise, yet thorough, and includes relevant technical terms and concepts.