will using semi-synthetic oil cause leaks for high mileage engines?

I have a 99 camry v6 with 123k and i'm planning to change my oil, i found valvoline max life high mileage semi-synthetic blend at walmart. I have heard that synthetics do cause leaks for high mileage cars. Would that be the same case for semi synthetic oils

4 Answers

  • cimra
    Lv 7
    9 years ago
    Favorite Answer

    If your car does not leak with mineral oil, it will be fine with a full synthetic or semi synthetic.

    This is from a Castrol website, but Mobil and Amzoil say the same thing: (some myths die hard), so once again, if you have no leaks with mineral oil, you will not have leaks with synthetic oil.



    Answer: MYTH! We're not sure who leaked that rumor, but synthetic motor oil does not cause leaks. It is 100% compatible with all automotive seal and gasket materials. In fact, SYNTEC meets additional ACEA seal protection requirements not even addressed in API specs.

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  • 9 years ago

    FWIW "synthetic" when referring to oil is just a marketing term now, and has been since Mobil lost an arbitration case against Castrol as to what the definition of synthetic is or is not. prior to that case synthetic was groups IV and higher, after group III was also allowed to be called synthetic although it is just a super refined version of regular oil, which is group II. This is because III is cheaper to produce than IV.

    Now probably 90% (just a WAG) of all synthetic oil is group III instead of IV. Synthetic blend is likely a mix of II and III.

    IOW no you don't have to worry about leaks. I switched a 92 Dodge Dynasty 3.3 to Mobil 1 5W30 non-EP at 180,000 miles back when for sure it was group IV and a 95 Grand Caravan also 3.3 to the same oil at 233,000 miles. Neither leaked after the switch.

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  • 9 years ago

    yes, using semi or full synthetic will cause oil leaks in a higher mileage vehicle. the advanced properties of synthetic oil make them able to lubricate better than conventional oils, they are able to squeeze through smaller openings than regular oils; like older, worn oil seals.

    it is ideal to switch to synthetic earlier in the life of an engine than when it's higher in mileage.

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  • 4 years ago

    finished man made oil is greater effective for any vehicle for quite a few motives. The detergent ingredients are greater suitable so the interior the engine will continuously be sparkling. It continues to be greater fluid at decreased temperatures for much less difficult beginning. The oil pump will stress an better volume of oil to frictional surfaces at as quickly as at initiate-up. The EP (extreme stress) ingredients are greater effective which guard cam lobes and lifter rollers or the flat surfaces on the backside of a few lifters. Low viscosity man made oil will run cooler with much less friction in any engine. you will get greater effective gas economic equipment. you could correctchronic greater miles between oil adjustments. substantial oil agencies say which you would be able to change returned and forth between the two forms of oil in case you so choose for.

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