Hello,
I now live in a tropical area.
Temperatures here are around 30 - 35 C. (around 90F) all year round and rarely go below 15 C. (60 F).
the W20 50 oil is twice cheaper than W5 40.
Do you think the W20 50 will be OK ( Nissan Sentra 1.6L 2003, fuel is 95 Octane Rating ) ?
Unless it is stated so in the manual, the answer is simple.
NO.
Check your owners manual. I am betting it says no. While your outside temps seem hot to a human,(we in North America will envy you in six months), engine temps are much higher. The lower number is the thickness at ambient temp. If the oil is thick (20) the engine does not get valuable lubrication at start up that lighter oil gives (5). I would not worry about the upper range, 40 vs 50. Pretty close enough.
Compare the cost of an oil change against a new engine, much cheaper in the long run to change oil with the proper weight.
5-30 is correct. Why do you think you need heavier oil? Worn out? Low oil pressure? How do you know? Is it burning oil? Keep adding cheap 5-30. Throw in a qt of 10-30 or whatever you have laying around
He said because it’s half the price…
No, it’s too heavy at cold start even for your tropical environment.
It’s half the price because no real demand except for people with worn out engines trying to eek out a few more miles.
If your car is not burning major oil stick with what is recommended in the owners manual.