V10 Motor Oil

Rodz wrote:

427435 wrote:
The engineers have a lot of things to consider (as do the marketing and lawyer types). Using 5w-20 oil in an engine will help MPG a bit. Meeting CAFE standards is a very big deal for the engineers and for Ford in general. If an engine can "get along" with a thinner oil for a reasonable time, they will move to it rather than use an oil that will extend the life of an engine to 100,000+ miles at the expense of MPG ratings.

Besides the recommended oils in Europe, Ford also specs a 5w-50 oil for their supercharged Mustang GT, here in the USA, where life might be a problem with a "light" oil.

Again, even 5w-20 oil is several hundred to several thousand cSt "thicker" at startup temps than a 5w-40 or 5w-50 oil is at operating temps. How many of you have seized a bearing during startup?? And if the first number is a 5w, you are fine for startup. The second number only relates to the much, much thinner "thickness" at operating temps. A higher number there will provide more bearing protection when your right foot is on the floor board climbing a long mountain grade, in a hot ambient, pulling a toad.

You are free, of course, to use whatever you want. My time spent in engine labs and vehicle engineering leads me to use something better than a 5w-20 oil in an engine that sees heavy loads.

Good imformative post. "427435"???? Is that what I think it is?