I have a 2000 Mitsubishi Lancer CK2 with a 4g15 dohc 16 valve engine. I've been using Valvoline VR1 15w40 engine oil and recently noticed its burning a bit more oil than usual. The tailpipe is clean with no oil residue and there are no leaks and only a slight smoke on cold starts. So I Was thinking of moving to a higher viscosity oil.

The issue I have is that in Sri Lanka the next viscosity of Valvoline VR1 is 10w60 and there is a Valvoline DuraBlend 20w50. Would love to get your expertise on which viscosity I should go for in my next oil change.

  • 15W-50 is already an oil that keeps its viscosity over a wider temperature range, 5W-50 is available that has a better cokd performance. However, using oil is usually an indicator of a leak or engine wear - so you should check that.
    – Solar Mike
    Jul 21, 2020 at 11:35
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    The fact that you have smoking on cold starts is usually an indication of valve guide or valve seal wear. Oil sitting in the cylinder head leaks down into the valve stem area and then is burned when you start the engine. This also happens while the engine is running but it is often not visible. Using higher viscosity oil may help a bit but it's not a long-term solution.
    – jwh20
    Jul 21, 2020 at 13:10
  • @SolarMike yes had a mechanic check that out and as jwh20 mentioned, they also diagnosed a possible faulty valve seal and its a head off job according to them as they dont want to risk of dropping a valve. Since am waiting to get my timing belt replaced as well wanted to have a temporary solution till then :) Jul 21, 2020 at 16:40
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    Generally speaking a higher viscosity oil provides better lubrication until you start reaching the point where it can no longer flow properly through the oil passages. It's not clear where that point is for a given engine, unfortunately. I suspect that going to 20W-50 is probably a better choice than the 10W-60 but that's just my opinion. You may see slightly less oil consumption with the heavier oil.
    – jwh20
    Jul 21, 2020 at 17:46
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    As long as the low number of viscosity is equal or lower you are fine, I have seen changing the lower number to a higher viscosity than recommended can break the oil pump in cold weather.
    – Moab
    Jul 21, 2020 at 17:56


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