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Old 09-24-2000, 07:23 PM
Posts: n/a
I hate to correct you on this, but I would NOT use 10W40 oil. It was determined several years back that 10W40 was not a good selection for small, hardworking engines. Here's why;

To make the 30 unit spread from 10 to 40 it takes an inordinate amount of VI additive. This additive is called Viscosity index Improver. In a small hardworking engine, and certainly in a turbo charged engine, this causes coking around the piston rings. In a large lumbering underworked engine, like a 460 in a pickup it's not such a problem, although personally I wouldn't use it in anything. The amount of additive necessary is not linear, it takes a lot more to make a 30 unit spread than it does to make a 25 unit spread. For this reason, 15W40, or 10W30 is a better choice.

Good luck,

Larry Bible
'01 C Class, Six Speed
'84 Euro 240D, 523K miles
'88 300E 5 Speed
'81 300D Daughter's Car
Over 800,000 miles in
Mercedes automobiles
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