Can some explain the differences in car oil to me?

Discussion in 'After Hours Lounge (Off Topic)' started by Neil Joseph, Oct 21, 2003.

  1. Neil Joseph

    Neil Joseph Lead Actor

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    I want to start using a thicker oil in my car but....

    You have choices of 5w30, 5w20, 10w40, etc etc etc. What are the meaning of the numbers and please don't laugh too hard at this non oil expert.
     
  2. Dennis Nicholls

    Dennis Nicholls Lead Actor

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  3. Neil Joseph

    Neil Joseph Lead Actor

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    So a 10w40 oil pours the same (cold) as a 10w30 oil but at hotter engine operating temperatures the 10w40 oil appears to be thicker than the 10w30 oil, correct?
     
  4. Kevin P

    Kevin P Screenwriter

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    The number before the W represents the cold viscosity, and the number afterward is the hot viscosity.

    A lower first number means the oil won't be as thick when it's cold, making the engine start easier in cold weather. A higher second number means the oil doesn't get too thin when it's hot, reducing its ability to protect the engine.

    The viscosity of oil you should use depends on your engine and your climate. In a cold climate, go with a lower first number, e.g. 5W30. In a temperate climate, 10W30. In a hot climate, or if you push the engine hard, 10W40 or even 20W50 (if there is such a thing). Check your owner's manual for the recommended viscosity for your engine.
     
  5. MarkHastings

    MarkHastings Executive Producer

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    Neil, just wanted to show my support in the "car oil challenged" category. I too have no clue. Interesting stuff. I only thought there was 10w30 and 10w40, I never heard of the 5's.

    My limited knowledge has always been the w30's were for cars and the w40's were for trucks (probably because of the 'pushing the engine' thing that Kevin explained).
     
  6. Craig

    Craig Second Unit

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    I don't know what model or year car you have, so this may not apply. Most cars of current manufacture use a very light oil not only for fuel mileage, but because they require a high flow rate as the oil circulates in the engine.

    It used to be pretty common to change to a heavier oil in the summer for example, but that's not recommended anymore. What I read stated that it was important to stick to the oil recommended by the manufacturer. Again, this may not apply to you depending on the year of your car.

    I always used to run Castrol 10w-40 most of the year, but I would switch to 20w-50 in the summer. Of course back in the late '60s I used to run 30 weight Valvoline in my Roadrunner year round (this was in North Fla). Back then the multi-weights either weren't produced or hadn't caught on.
     
  7. Todd Hochard

    Todd Hochard Cinematographer

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  9. Jack Shappa

    Jack Shappa Second Unit

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    I tried WD-40 and now my engine doesn't squeak... Or start...

    - JS
     
  10. Dennis Nicholls

    Dennis Nicholls Lead Actor

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    Neil,
    From your lat/long you live in Buffalo or Niagra Falls. Why the heck would you want to run thick oil in that frozen wilderness?

    WD-40 isn't oil at all. "Water Displacement 40" is its full name.

    The trend lately is to go to thinner oils due to better tolerance control in modern engines. My 1978 VW used 20W-50, my 1992 Miata uses 10W-30, and now my 2001 Ford F-150 uses 5W-20. Ford and Honda have both gone to 5W-20 year around.
     
  11. Clinton McClure

    Clinton McClure Casual Enthusiast

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    My 2000 Celica uses 5W-30. 97,000 miles and runs like a top. [​IMG]
     
  12. Todd Calhoun

    Todd Calhoun Agent

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  13. Philip_G

    Philip_G Producer

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    wow, I haven't had a car in years that required anything but 5w30, in fact, it was a 1990 jeep wrangler, IIRC it requred 10w30, everything since has been 5w30 (and japanese)
    I always ran it year around (synthetic) and my car started fine with a good battery, and no block heater down to -30 or a bit colder (F)
     
  14. Todd Hochard

    Todd Hochard Cinematographer

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    I forgot to add-

    If you want a generic recommendation, based on your location-

    Mobil 1 Synthetic- 0W-30 in the winter, 5W-30 in the summer.
     
  15. brentl

    brentl Cinematographer

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    Mobil 1 Synthetic is a great idea, I've heard nothing bad about it.

    I use 5-20 Honda stuff now, but after a year with my car(2003 civicLX) I'm switching to 5-30 mobil 1.

    B
     
  16. Philip_G

    Philip_G Producer

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    plus walmart usually sells mobil 1 for 3.88 a qt, probably the cheapest full synthetic you'll find.
     
  17. Jack Shappa

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  18. MarkHastings

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  19. Mike Voigt

    Mike Voigt Supporting Actor

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    The change of the viscosity is done using so-called VI Modifiers, viscosity index modifiers.

    Higher viscosity means it does not "move" as easily as lower numbers. The problem with real low numbers is that they may be too light when warmed up, i.e. they do not give you the necessary buffer between moving parts. Hence the VI mods, to artificially increase the viscosity to a higher point.

    The fun starts when you try to analyze the oil to figure out what's happening. It is positively amazing what you can find.

    The whole point is to retain the very small gap between moving metal parts. Higher viscosity ~ better load-carrying capability, but lower flowability.
     
  20. Christ Reynolds

    Christ Reynolds Producer

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