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oil question

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by GMMANIAC, May 15, 2002.

  1. GMMANIAC

    GMMANIAC Registered Member

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    Along with my '89 K5 I have a '99 4X4 Suburban with a 5.7 Vortec engine. I'm using Mobile 1 15w/50 in my Blazer and Mobil 1 10w/30 in my Suburban. Since the cost of oil is almost $5 a quart I have been thinking of switching back to conventional oil and was wondering if anyone is using anything other than 10w/30 in a Vortec engine. The owners manual suggests not using anything above a 10w/30 but here in Texas I want something that won't thin out. I use 15w/40 at my Mercedes shop and was considering using it in my Suburban. Any thoughts?
     
  2. txbartman

    txbartman 1/2 ton status

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    I have used 10W30 in all my vehicles here in TX for many, many years and have never had a problem. Key for me is to change it regularly. Remember, the engine is designed to operate at a specific temperature range regardless of whether you are in TX or Alaska. Now, obvisouly, it will vary some, but not too much. Engine temperature has more of an impact on oil temp and oil breakdown than the air temp since it is an indirect impact.

    At worse case scenario, or if you run your oil longer than 3,000 miles between changes, you could up to 20W50. I have done that a few times but have seen no difference when the oil is changed from the 10W30.
     
  3. GMMANIAC

    GMMANIAC Registered Member

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    Working on Mercedes for a living I'm a fanatic with my maintence. I've extended my oil changes to 5000 miles only do to using full synthetic oil. My conscern for using a heavier weight conventional was breakdown during summer offroading and highway driving.
     
  4. Thunder

    Thunder 3/4 ton status

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    I use nothing but good quality conventional 10-30 in my 89K5 And my other 4 GM vehicles. I use it very hard in the summer. Towing, off road, ect
    I have no problems with it. Change oil every 3K. The Engine in my 89 has never been rebuilt and is very strong. My other rides range in age from 89 to 99. All have the original engines/ and run great. But I also use and additive called:
    (clicky)<a target="_blank" href=http://www.tufoil.com> tufoil.com</a>
    been using it for 10 years in all my car/boat engines and drive train... Its Good Stuff !
     
  5. txbartman

    txbartman 1/2 ton status

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    I understand the maintenance thing. I am a pretty strong on it just because it can save so much down the road. I also understand your concerns about breakdown. I have never had a GOOD 10W30 breakdown on me here in our hot state. Its also a fine line to walk. Afterall, heavy oil means more work for the engine. More work for the engine means higher temperatures. Higher temperatures mean more likelihood for breakdown. Catch-22. I think you would be fine with either a good brand of 10W30 or a good 20W50. Whichever would give you better piece of mind.
     

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