Q: I used 5w-20 engine oil of instead of 5w-40 as recommended in the manual

asked by on November 15, 2016

So I running low on oil in my 991 GT3 and so I stopped by the nearest gas station, quickly grabbed a Mobil 1 5w-20 and began pouring it in. Halfway into it I suddenly remembered it was 5w-40 and not 5w-20. I poured a little over half a bottle of 5w-20 inside. What kind of damage will this do? Can I simply just add 5w-40?

My car has 13500 miles.
My car has an automatic transmission.

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The most important thing is do not run the engine low on oil even using a lighter weight oil. Since you did put in the incorrect oil I would recommend not running the vehicle too hard until you get the oil and filter changed. Your engine should use Mobile 1 0w40 normally for all temperatures.

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