So, I emailed Exxon-Mobil and asked their tech section about my car, and they said, regarding using non-synthetic oil, "You are not doing harm but you are definitely not doing the best for your vehicle." They also have a oil selector: http://www.mobiloil.com/USA-English/MotorOil/Car_Care/Vehicle_Chooser/VehicleChooser.aspx?option=2, which suggested just about every oil level they manufacture for everything from "Premium Protection" to "Superior Protection".
WTF? They can't even make up their minds!
Current Vehicle:
Year: 2007
Make: Mazda
Model: 3
Engine Type: 4cyl. 2.3Liter Turbocharged
Premium Protection
Mobil Clean 5000 5W-30
Mobil Clean 5000 5W-30 is a conventional motor oil that delivers proven protection of critical engine parts from lubricant-related failure for 5,000 miles or six months, whichever comes first. It is designed to exceed most engine warranty requirements.
Also Consider:
Superior Protection
Mobil Clean 7500 5W-30
Mobil Clean 7500 5W-30 is a synthetic blend motor oil designed to exceed engine warranty requirements. It delivers guaranteed performance and protection for up to 7,500 miles or 6 months, whichever comes first. Mobil Clean 7500 has 18 percent more cleaning agents than Mobil Clean 5000 to keep your engine cleaner longer.
Ultimate Protection
Mobil 1 Extended Performance 5W-30
Mobil 1 Extended Performance 5W-30 fully synthetic motor oil is designed for today's longer service intervals. It provides guaranteed performance and protection for 15,000 miles or one year. Mobil 1 Extended Performance products with the Advanced SuperSyn System contain extra performance additives to help deliver outstanding engine protection.
Mobil 1 5W-30
A fully synthetic motor oil, Mobil 1 5W-30 with SuperSyn Technology, is the approved and the first choice of many premium car manufacturers, including Corvette.
Mobil 1 0W-30 Advanced Fuel Economy
For improved fuel economy, consider using Mobil 1 0W-30 Advanced Fuel Economy which is engineered to deliver outstanding engine protection and to offer improved fuel economy in vehicles where SAE 0W-30, 5W-30 or 10W-30 oil is recommended.
Mobil 1 Truck & SUV 5W-30
A fully synthetic motor oil, Mobil 1 Truck & SUV 5W-30 is engineered for gasoline engines in hard-working trucks, vans, SUVs and recreational vehicles.
WTF? They can't even make up their minds!
Current Vehicle:
Year: 2007
Make: Mazda
Model: 3
Engine Type: 4cyl. 2.3Liter Turbocharged
Premium Protection
Mobil Clean 5000 5W-30
Mobil Clean 5000 5W-30 is a conventional motor oil that delivers proven protection of critical engine parts from lubricant-related failure for 5,000 miles or six months, whichever comes first. It is designed to exceed most engine warranty requirements.
Also Consider:
Superior Protection
Mobil Clean 7500 5W-30
Mobil Clean 7500 5W-30 is a synthetic blend motor oil designed to exceed engine warranty requirements. It delivers guaranteed performance and protection for up to 7,500 miles or 6 months, whichever comes first. Mobil Clean 7500 has 18 percent more cleaning agents than Mobil Clean 5000 to keep your engine cleaner longer.
Ultimate Protection
Mobil 1 Extended Performance 5W-30
Mobil 1 Extended Performance 5W-30 fully synthetic motor oil is designed for today's longer service intervals. It provides guaranteed performance and protection for 15,000 miles or one year. Mobil 1 Extended Performance products with the Advanced SuperSyn System contain extra performance additives to help deliver outstanding engine protection.
Mobil 1 5W-30
A fully synthetic motor oil, Mobil 1 5W-30 with SuperSyn Technology, is the approved and the first choice of many premium car manufacturers, including Corvette.
Mobil 1 0W-30 Advanced Fuel Economy
For improved fuel economy, consider using Mobil 1 0W-30 Advanced Fuel Economy which is engineered to deliver outstanding engine protection and to offer improved fuel economy in vehicles where SAE 0W-30, 5W-30 or 10W-30 oil is recommended.
Mobil 1 Truck & SUV 5W-30
A fully synthetic motor oil, Mobil 1 Truck & SUV 5W-30 is engineered for gasoline engines in hard-working trucks, vans, SUVs and recreational vehicles.