Note: Nothing in this standard supercedes applicable laws and regulations.

Note: In the event of conflict between the English and domestic language, the English language shall take precedence.

Purpose/Material Description.

The candidates for diesel detergent additive package shall be used primarily to clean-up injector deposits from compression ignition engines.

Note: The additives shall not contain any metallic content or methanol unless exclusively specified by GM Fuels Group.

Symbols.

Not applicable.

Applicability.

The additives should be able to clean any one (1) or all of the types of fuel injector/combustion chamber deposits caused by diesel and biodiesel blended fuels on all GM diesel engine applications including in-direct fuel injection systems and modern common rail fuel injection systems. (See a through d).

a. Deposits produced by diesel fuel degradation.

b. Deposits produced by oxidation of biodiesel fuels.

c. Polymeric organic deposits related to specific additive chemistries.

d. Alkali metal carboxylates deposits related to interactions of specific fuel additives with fuel contaminants.

The types of deposits that the additives would be required to clean up are not limited to the ones described in 1.3 (a through d). However, the primary focus of this GMW specification is to provide the Global GM Service Network, GM Customer Care and Aftermarket, a chemical detergent tool to clean up existing deposits from low quality fuels. As such application of the additives is envisioned for limited time and shall be commonly used for one (1) tank cleanup of injector deposits.

The tests defined in Section 3, should be regarded as minimum requirements for compliance for diesel fuel detergent additives. Additional requirements may be defined based on the type of additive, its specific chemistry, and cleaning application. This specification applies to diesel and biodiesel blended fuels only.

Remarks.

Program specific technical specifications may include additional requirements that are not referenced in this document and may supercede any requirements included in this document. In case of any conflicts between this document and the program specific technical specifications, the program specific technical specifications shall take precedence.

This specification describes the technical requirements for GM aftermarket diesel fuel detergent packages. The GM Powertrain (GMPT) Fuels Group will evaluate the technical merits of the additive package prior to being considered by GM Purchasing for the Customer Care and Aftersales Division. These specifications will cover requirements for performance as well as requirements for ensuring compatibility of the additives with fuel system, engine, and the after treatment catalyst system. The requirements are a combination of standardized fuel industry engine dynamometer cleanliness tests, chemical laboratory tests, and supplier specific vehicle performance demonstration tests, as a basis for consistent fuel additives performance evaluation.