Cloud Point

Cloud Point (CP) is the temperature at which the paraffin wax begins to solidify, precipitate from the fuel and the fuel begins to appear cloudy as measured by ASTM D2500 method. The wax formation can be identified with fuel filter problems. The fuel filter and possibly the fuel lines could become clogged with waxes or gels and potentially starve the engine of fuel.

The only effective means of lowering a fuel's Cloud Point is by blending with No. 1 Diesel Fuel. Cold Flow Additives are typically not very effective at lowering the Cloud Point; they generally are effective at lowering the CFPP (see below).

Although cold flow additives may be effective at improving the cold weather operability of diesel fuel, extreme caution must be taken not to use too much additive. As with any fuel additive, excessive use may cause operability problems. The best and most effective means of improving the cold weather operability of No. 2 Diesel Fuel is to blend with No. 1 Diesel Fuel until its Cloud Point is equal to or below the expected ambient temperature. Refer to Allowed Fuel Additives for further information.