Dear LubesnGreases,

In Octobers Automotive column, Heavy-duty Engine Oils: What Lies Ahead, Steve Swedberg commented that based upon conversations with heavy-duty OEMs, it is very unlikely that they would specify an SAE 5W-30 for their engines. In the context of the need for 3.5 centiPoise high temperature/high shear viscosity for todays engines, and the potential for confusion with passenger car engine oils carrying a 2.9 cP HTHS, I can understand the initial hesita-tion. However I would like to point out that BP under the Castrol Elixion brand has globally marketed an SAE 5W-30 heavy-duty engine oil for some years. This oil has been accepted by most heavy-duty engine manufacturers in the form of specification approvals and, where available, prod-uct listings.

The SAE 5W-30 grade is widely accepted and widely used by European OEMs, who now account for the major part of heavy-duty diesel engine technology globally. Also, Japanese heavy-duty diesel OEMs are actively looking at 5W-30s for fuel economy. The oil, as you can appreciate, is formulated to a 3.5 cP minimum HTHS level and histori-cally has met API CI-4.

More recently an SAE 5W-30 was introduced in North America, again under the Castrol Elixion brand, that meets the API CJ-4 category for modern heavy-duty diesel engines. This product has again been reviewed and accepted by OEMs such as Cummins Engine and Volvo/Mack Powertrain. In the case of Volvo/Mack, we have recognition for their approved-product list. There has been a significant interest in the performance of lighter viscosity heavy-duty engine oils, especially in the ability to improve fuel economy.

While I appreciate the hesitation in a general recommen-dation for 5W-30 for heavy-duty diesel applications, this needs to be balanced with the fact that approved technolo-gy in this grade does exist to meet the needs of heavy-duty OEMs, and there has been expressed interest in the grade.

Given the direction for the future and the interest in dri-ving improvements in fuel economy, it is our anticipation that SAE 5W-30 will gain momentum with OEMs and cus-tomers alike, and shape recommendations in the future.

John Demko,

BP Lubricants Americas, Wayne, N.J.