SAE 0W30 vs. SAE 30 oil

Discussion in 'Mechanic and Repair' started by mcdansley, Jun 26, 2005.

  1. mcdansley

    mcdansley LawnSite Member
    Posts: 14

    What is the difference between SAE 0W30 vs. SAE 30 motor oil for 4-cycle engines? Are they the same? The SAE 0W30 is a full synthetic made by Mobil. Is it safe to run in lawn mower engines in the place of SAE 30? It is rated SL.
     
  2. Redneckn

    Redneckn LawnSite Senior Member
    Posts: 294

    I figured everybody would have an opinion on this. I am all knowed up on oil so i will venture off into it. If the engine calls for 30 then use 30. if it says you can use either, then use whatever you want.
    me? I wouldnt every use a synthetic for anything.. but thats just me.
     
  3. Scapegoat

    Scapegoat LawnSite Member
    Posts: 249

    I'd like to hear why you wouldn't "use a synthetic for anything." Just wondering. I'm no expert, but I do know my current truck is the first vehicle I've had that hasn't some kind of fluid leak at it's age and mileage (1997 w/ 98K miles) and it happens to be the first vehicle I've keep synthetic in everywhere.

    Could be coincidence? I dunno.
     
  4. Restrorob

    Restrorob LawnSite Fanatic
    Posts: 11,024


    I would kinda lean towards coincidence, I own a (1986 conversion van W/ 163,000) no leak miles. Nothing but Castrol GTX for me. :p
     
  5. CCWKen

    CCWKen LawnSite Member
    Posts: 113

    0W30 is NOT the same as 30. Straight 30 is just that. The viscosity remains at 30 in it's operating range. "0W" is the Winter designation and means the oil's viscosity will drop to 0 in it's cold operating range and raise to 30 as it heats up.

    Check your owners manual. Most of the mfgs. of newer engines suggest using synthetic and multigrade oil over single grade oils for certain temperatures. Check your OM to be sure.
     
  6. Oldtimer

    Oldtimer LawnSite Bronze Member
    Posts: 1,455

    I have a '89 GMC 2500 6.2 diesel with >200K and it has never had an oil leak or synthetic oil.
     
  7. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,104

    Dumb question here. I know the higher the number the thicker the oil is so what would "0" be, WD-40?
     
  8. UNISCAPER

    UNISCAPER LawnSite Bronze Member
    Posts: 1,426

    There was a time when every tech school I attended warned specifically against synthetic oils, and synthetic additives. I disregarded the warnings, and ran Valvoline Syn-Flow, the full synthetic oil in their line up. We had internal cylinder head temp gauges and oil temp guages on a couple select machines. When we ran synthetics, combustion chamber temps dropped 120°and internal oil dropped 15°. We then added an external oil cooler to drop the temps another 35°. We had a couple Kohler 22HP V-twins that dangeled with 5000 plus hours, cylinder heads never removed.
    You don't want to run synthetics as break in oil, because it is so slick the rings won't seat. After break in, that is all we run. Call it what you will, the stuff works. Mobil one has made very significant advances in synthetic oil technology. We still run Valvoline, as it is the number one most widely used oil by engine builders from NASCAR, NHRA, CART, ARCA, etc etc.

    I found it comical that when the Pennzoil car came to the garage, the crew chief dumped Valvoline into the crankcase.
     
  9. topsites

    topsites LawnSite Fanatic
    Posts: 21,654

    NO they are NOT the same!

    SAE 0w30 is a multi-grade oil whose viscosity ranges between 0 and 30.
    SAE 30 is a single grade oil whose viscosity is a stable 30.

    As for me, I run 10w30 synth.blend in my Kohlers, 10w40 synth.blend in the briggs, and 5w30 synth.blend in the bmw's.
     
  10. topsites

    topsites LawnSite Fanatic
    Posts: 21,654

    Maybe you don't have anything that requires it, but it still wouldn't hurt to run it and it would likely improve things. See, if you owned a bmw you would know the cold, hard truth: The manufacturers of real engines such as what goes in a bmw absolutely require that you run synthetics or you will void the warranty of the engine.
     

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