Why doesn Delvac 1 come in a 15w-40 viscosity grade?
The synthetic base stock used in Delvac 1 naturally has better low-temperature flow characteristics than a conventional engine oil. This results in the SAE 5W grade, which provides easier starting and faster oil flow characteristics than an SAE 15W grade. With the excellent film strength of the synthetic-based stock, and the tuned additive package, we can offer the advantages of better low-temperature performance and improved fuel economy — while also providing better lubrication protection at hot engine operating conditions than a conventional SAE 15W-40.
