I found this on the owners manual. Z • 3.5L V6 SHO/2.0L EcoBoost® engines
“Regular” unleaded gasoline with a pump (R+M)/2 octane rating of 87 is
recommended. Some stations offer fuels posted as “Regular” with an
octane rating below 87, particularly in high altitude areas. Fuels with
octane levels below 87 are not recommended. Premium fuel will provide
improved performance and is recommended for severe duty usage such
as trailer tow.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily while you are using fuel with the recommended octane
rating, see your authorized dealer to prevent any engine damage. Avoid running out of fuel because this situation may have an adverse
effect on powertrain components. For consistent results when filling the fuel tank:
• Turn the ignition off before fueling; an inaccurate reading results if the
engine is left running.
• Use the same fill rate (low–medium–high) each time the tank is filled.
• Allow no more than two automatic click–offs when filling.
Results are most accurate when the filling method is consistent. Do not measure fuel economy during the first 1000 miles
(1600 kilometers) of driving (this is your engine’s break-in period); a
more accurate measurement is obtained after 2000 miles–3000 miles
(3200 kilometers–4800 kilometers). Also, fuel expense, frequency of
fill-ups or fuel gauge readings are not accurate ways to measure fuel
economy.
1. Fill the fuel tank completely and record the initial odometer reading.
2. Each time you fill the tank, record the amount of fuel added.
3. After at least three to five tank fill-ups, fill the fuel tank and record
the current odometer reading.
4. Subtract your initial odometer reading from the current odometer
reading.
5. Calculate fuel economy as follows:
Standard: Divide miles traveled by gallons used.
Metric: Multiply liters used by 100, then divide by kilometers traveled. Keep a record for at least one month and record the type of driving
(city or highway). This provides an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter show how temperature impacts fuel economy.
In general, lower temperatures mean lower fuel economy.
“Regular” unleaded gasoline with a pump (R+M)/2 octane rating of 87 is
recommended. Some stations offer fuels posted as “Regular” with an
octane rating below 87, particularly in high altitude areas. Fuels with
octane levels below 87 are not recommended. Premium fuel will provide
improved performance and is recommended for severe duty usage such
as trailer tow.
Do not be concerned if your engine sometimes knocks lightly. However, if
it knocks heavily while you are using fuel with the recommended octane
rating, see your authorized dealer to prevent any engine damage. Avoid running out of fuel because this situation may have an adverse
effect on powertrain components. For consistent results when filling the fuel tank:
• Turn the ignition off before fueling; an inaccurate reading results if the
engine is left running.
• Use the same fill rate (low–medium–high) each time the tank is filled.
• Allow no more than two automatic click–offs when filling.
Results are most accurate when the filling method is consistent. Do not measure fuel economy during the first 1000 miles
(1600 kilometers) of driving (this is your engine’s break-in period); a
more accurate measurement is obtained after 2000 miles–3000 miles
(3200 kilometers–4800 kilometers). Also, fuel expense, frequency of
fill-ups or fuel gauge readings are not accurate ways to measure fuel
economy.
1. Fill the fuel tank completely and record the initial odometer reading.
2. Each time you fill the tank, record the amount of fuel added.
3. After at least three to five tank fill-ups, fill the fuel tank and record
the current odometer reading.
4. Subtract your initial odometer reading from the current odometer
reading.
5. Calculate fuel economy as follows:
Standard: Divide miles traveled by gallons used.
Metric: Multiply liters used by 100, then divide by kilometers traveled. Keep a record for at least one month and record the type of driving
(city or highway). This provides an accurate estimate of the vehicle’s fuel
economy under current driving conditions. Additionally, keeping records
during summer and winter show how temperature impacts fuel economy.
In general, lower temperatures mean lower fuel economy.
