Your vehicle is designed to operate using regular unleaded fuel with an 87 octane. Ford recommends that using gasoline with an octane rating lower than 87 can cause persistent and heavy knocking, and may cause internal engine damage.
If your vehicle is having problems with rough idle or hesitation when the engine is cold, it may be caused by low volatility fuel. If this occurs try a different grade or brand of fuel.Diesel Engines
Fuel makers produce two grades of diesel fuel, No. 1 and No. 2, for use in automotive diesel engines. Generally speaking, No. 2 fuel is recommended over No. 1 for driving in temperatures above 20°F (7°C). In fact, in many areas, No. 2 diesel is the only fuel available. By comparison, No. 2 diesel fuel is less volatile than No. 1 fuel, and gives better fuel economy. No. 2 fuel is also a better injection pump lubricant.
Two important characteristics of diesel fuel are its cetane number and its viscosity.
The cetane number of a diesel fuel refers to the ease with which a diesel fuel ignites. High cetane numbers mean that the fuel will ignite with relative ease or that it ignites well at low temperatures. Naturally, the lower the cetane number, the higher the temperature must be to ignite the fuel. Most commercial fuels have cetane numbers that range from 35 to 65. No. 1 diesel fuel generally has a higher cetane rating than No. 2 fuel.
Viscosity is the ability of a liquid, in this case diesel fuel, to flow. Using straight No. 2 diesel fuel below 20°F (7°C) can cause problems, because this fuel tends to become cloudy, meaning wax crystals begin forming in the fuel. 20°F (7°C) is often call the cloud point for No. 2 fuel. In extremely cold weather, No. 2 fuel can stop flowing altogether. In either case, fuel flow is restricted, which can result in no start condition or poor engine performance. Fuel manufacturers often winterize No. 2 diesel fuel by using various fuel additives and blends (no. 1 diesel fuel, kerosene, etc.) to lower its wintertime viscosity. Generally speaking, though, No. 1 diesel fuel is more satisfactory in extremely cold weather.
Your 2.0L diesel engine is designed to use number 2-D diesel fuel. Use of number 1-D diesel fuel in temperatures below 20°F (7°C) is acceptable, but not necessary.
Do not use number 1-D diesel fuel in temperatures above 20°F (7°C), as damage to the engine may result. Also, fuel economy will be reduced with the use of number 1-D diesel fuel.
The 2.0L diesel engines are equipped with an electric fuel heater to prevent cold fuel problems. For best results in cold weather use winterized number 2-D diesel fuel which is blended to minimize cold weather operation problems.
See Figures 1 and 2
Gasoline engines are required to use engine oil meeting API classification SG, such as SG/CC or SG/CD, or the latest superseding version. Viscosity grade 10W-30 or 10W-40 is recommended for use in pre-1984 models; 5W-30 or 10W-30 is recommended for use in 1984 and later models. See the viscosity-to-temperature chart in this section.
Diesel engines require different engine oil from those used in gasoline engines. Besides doing the things gasoline engine oil does, diesel oil must also deal with increased engine heat and the diesel blow-by gases, which create highly corrosive sulfuric acid.
If your vehicle is equipped with a diesel engine, be sure to check your owner's manual for the recommended oil viscosity to be used. There should be a diesel engine supplement included with your owner's manual.