New Neighbor Said: "You're killing your engine"...thoughts?

[thstone]

10w-40 is the perfect oil weight for the temperature ranges here in LA. You will definitely not destroy your engine.

Mobil 1 High Mileage has a more extensive anti-wear and seal conditioning package than regular Mobil 1.

[The Radium King]

the first number is cold weight, the second weight at temperature. colder regions require a lighter cold weight so that the oil has adequate fluidity during a cold start. once to temp all else is equal. in warm temperatures the cold weight is really moot, except - ask your neighbour if he worries about his chain tensioner paddles at all; with that runny oil of his all the oil runs back down to the bottom of the engine so on a cold start the chain is flapping against a dry paddle - does he see a lot of green black chunks of plastic in his oil filter?