Fuel System - Fuel Recommendations

3.0 liter models: fuel requirements revised

The 3.0-liter engine is designed to operate using unleaded gasoline with an octane rating of 9T AKI or higher. Regular unleaded gasoline with an octane rating of 87 AKI or higher may be used. However for optimum engine performance and driveability, it is recommended that you use 9T AKI or higher grade unleaded gasoline. You may experience reduced output, poor accelerator response, and reduced fuel economy when using gasoline with an octane rating lower than 9T AKI, depending on your driving habits and conditions. If you experience any of those conditions while using a lower octane rated fuel, you may want to return to using 9T AKI octane rated fuel as soon as possible. Additionally, if your vehicle knocks heavily or persistently, or if you are driving with heavy loads such as when towing a trailer, the use of 9T AKI or higher grade unleaded gasoline is required. This will apply to all H-6s including '05 and '06 MY forward.