By Brent Peterson
Since cooler weather has arrived, I have had several questions asked regarding diesel fuel additives for operating our motorhomes in colder weather, and for algae protection.
I decided the best answer was an excerpt from Cummins’s own Service Bulletin Number 3379001-05.
ADDITIVES
Cummins Engine Company neither approves nor disapproves of the use of any fuel additive, fuel extender, fuel system modification or the use of any device not manufactured or sold by Cummins Engine Company or its subsidiaries. Engine damage, service issues or performance problems that occur due to the use of these products are NOT considered a defect in workmanship and/or material as supplied by Cummins Engine Company and are NOT compensable under the Cummins warranty.
Cummins engines are designed, developed, rated and built to operate on commercially available No. 2-d diesel fuel, therefore, it is not our policy to recommend fuel additives.
In extreme situations, when available fuels are of poor quality or problems exist which are peculiar to certain operations, additives can be used; however, Cummins recommends consultation with the fuel supplier or Cummins Service Engineering Department prior to use of fuel additives.
Among the situation where additives could prove useful are the following:
1. A pour point depressant or flow improver additive can help with high pour point fuels. These depressants do not affect the cloud point (waxing).
2. An anti-oxidant or storage stability additive can help with fuel system deposits and poor storage stability.
3. A biocide or fungicide can help when fuels are prone to contamination with bacteria or fungus.
4. An anti-icer can help prevent ice formation in wet fuel during cold weather.
5. A cetane improver additive can be used with low cetane fuels.
6. Cummins Premium Plus – Diesel Fuel Additive can be used to clean carbon deposits from injectors and improve lubricity in fuels that fall below the recommended lubricity specifications in Table 1. Refer to Cummins Service Information Bulletin 89S1B6-2 for more information on cleaning fuel injectors with Premium Plus. Premium Plus is the ONLY diesel fuel additive recommended by Cummins for use with fuels that do not meet the lubricity specifications in Table 1.
Premium diesel fuel may contain several additives that can accomplish the same as buying additives and adding to the diesel fuel.
Cummins recommends the use of a premium diesel fuel during winter (ambient conditions at –7ºC [20ºF] or below) operating conditions.
Great care must be exercised in the choice and use of additives. Some fuel additives can be harmful to the engine. Fuel additives containing ash forming materials will cause combustion chamber deposits. Most legitimate fuel additives perform only one function. Multifunctional fuel additives are mixtures of several additives. All fuel additives perform differently in different fuels; therefore, the additive used must be one to which the fuel will respond. There are no known additives that increase the power or improve the efficiency of a properly maintained engine.