Ford F-650 Owner's Manual page 206

Maintenance and Specifications
If you must replace the fuel filler cap, replace it with a genuine
Ford or Motorcraft part. The customer warranty may be void for
any damage to the fuel tank or fuel system if a genuine Ford or
Motorcraft fuel filler cap is not used.
WARNING: If you do not use the proper fuel filler cap,
excessive pressure or vacuum in the fuel tank may damage the
fuel system or cause the fuel cap to disengage in a collision, which may
result in possible personal injury.
Choosing the right fuel - diesel engines
Use only Ultra Low Sulfur (15 ppm Sulfur Maximum) number 1-D
or 2-D diesel fuel in your diesel engine. The engine and exhaust
system were designed to only use this fuel. Look for the
ULTRA-LOW SULFUR HIGHWAY DIESEL FUEL (15 ppm Sulfur
Maximum) label on fuel pumps when purchasing your fuel.
Number 1-D or winter blend number 2-D fuel is recommended at
temperatures below 20°F (-7°C) (see Cold weather operation in the
Driving chapter. Diesel fuel containing no more than 20% biodiesel may
be used. Biodiesel fuel is a product that has been converted from
renewable fuel sources, including vegetable oil, animal fat and cooking
oil. Raw or refined vegetable oil, animal fat, cooking oil or recycled
greases should not be used. All biodiesel up to B20 must comply with
ASTM D7467 standards.
Refer to your engine operator's manual for additional information and
restrictions regarding use of biodiesel fuel.
WARNING: Do not use home heating oil or any diesel fuel not
intended for highway use. Red dye is used to identify fuels
intended for agricultural and non-highway use. Damage to the fuel
injection system, engine and exhaust catalyst can occur if an improper
fuel is used. Do not add gasoline, gasohol or alcohol to diesel fuel. This
practice creates a serious fire hazard and engine performance
problems.
Note: Use of any fuel other than those recommended may cause
powertrain damage, a loss of vehicle performance, and repairs may not
be covered under warranty.
206
2012 F-650/750 (f67)
Supplement, 2nd Printing
USA (fus)