5W30 VS. 10W30

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Feb 28, 2003
Cajun Country, La.
97 F150,4.2V6,85K miles.Ive been using 10W30 Chevron Supreme with Motorcraft filters since I bought the truck used with 64K miles.Manual calls for 5W30,and alot of people tell me I need to run 5W30,but alot also say being I live in Florida I should stick with 10W30.Any comments,advice,suggestions,opinions are greatly appreciated. [Patriot]
10W30 is fine for your car in a warmer climate. In a higher mileage engine with increased clearances, consumptions issues can sometimes arise with the use of thinner oils.
I run that exact same model with Penn 10w-30 for 100k. Now run Schaeffer's 15w-40 and have for the past 9k with no ill effects. No cold starting problems.
And, have you had the gaskets replaced--timing cover and manifold? 97 V6 has a problem. Check it out.
In warm climates there is no need to run 5w30 at all. 10w30 will flow just as well on a cold startup when it's 90 degrees outside. Even when it's 50 degrees out there is very little difference in viscosity between the two, it's only when it's much colder where the 5w30 flows better.
10W-30 has the advantage of less reliance on the VI package to maintain hot viscosity under shear conditions. I used 5W-30 once: during the continuation of initial break-in after changing out Hyundai's factory fill oil at 600 miles. [ April 02, 2003, 07:15 PM: Message edited by: Ray H ]
Originally posted by Pluto5: Patman, what about temps in the 50-90 range? Should I change to 10W-30 now?
It depends on which 5w30 you are running. If it's a dino 5w30, then yes, switch to 10w30. But if it's a good synthetic 5w30 (or Schaeffer blend, which for all intents and purposes, I consider synthetic) it can handle the high too. I know it sounds like I'm contradicting my earlier statement in this thread but I'm not. I'm simply saying if you don't drive in cold weather, you don't need 5w30, but if you're running a good 5w30 synthetic, it's safe to use in the summer too.
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