High mileage motor oil

2003 HYUNDAI SONATA
209,763 MILES • 4 CYL • AUTOMATIC
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CANDIE BENITEZ
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  • 1 POST
I need to put oil in, normally I use 10w40. But recently my Sweet car has really been acting up. So I'm wondering if maybe I should try using 5w30? Thank you for your advice.
Apr 27, 2016 at 2:21 PM
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CARADIODOC
  • CAR REPAIR CONTRIBUTOR
  • 34,308 POSTS
Thinner oil runs out of the bearings faster which results in lower pressure. With high mileage you get increased bearing wear and therefore greater clearance and it's even easier for the oil to run out. You want thicker oil, meaning a higher viscosity. 10W-40 is likely already thicker than what was originally called for so I'd stick with that. That will find it harder to ooze out of the bearings so oil pressure will tend to remain higher, which is desirable.
Apr 27, 2016 at 3:13 PM
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