I daily a 2017 Mazda 3 iSport hatchback. It is time for another oil change and I brain farted on what weight oil so I pulled out the owners manual (online) and according to it I should use 0W20 in the USA, Canada and Puerto Rico but outside of those areas I should use 5W30. I can only imagine that is due to fuel economy standards. Any other thoughts?
0W 20 vs 5W 30 in a 2017 Mazda 3
- Thread starter Lucid_Moments
- Start date
There are likely tens of not hundreds of existing threads on this exact topic. Some of which are currently in discussion.
Well Canadian and Puerto Rico oil are so different from American oil your engine would likely explode! 
Given your location, 5w30 all day.
For Mazda North America USA, Canada and Puerto Rico all follow CAFE regulations. Mexico does not follow CAFE. The 5w30 for Mexico in your OM is API SM rating, there is not a specific stated API rating but needs ILSAC seal for our area. I can only speculate on why Mexico is different. Oil availability, severe service, CAFE, exc. Around the world the 5w30 shows up but the oil service interval is longer. Also Japan and North America (except Mexico) oil formulation is made by Idemitsu and the 0w-20 is loaded with dinuclear moly. That factory installed oil (0w-20) ships around the world but for Europe another Mazda oil made by Total (0w-20 and 5w30) is used after the break in. If you buy a Mazda with a turbo the oil used is 5w30 and does not have that high dinuclear moly.
Thank you very much for actually answering my question.
0w20 is only for fuel economy, and it’s fractional if that. Considering your winter temps are always above 0*F and your summers are 90*+, I’d personally run the Xw30 all the time over the 20wt. Heck, above 0* you could even run 10w30 year round and be just fine.
Depending on his other vehicles, 5w30 would likely be a great fleet oil to save shelf space & simplify. The Mazda engines are generally bulletproof anyways, so I can’t argue with your comment
I already bought some 0w-20 for the Mazda and will run it until the next oil change which will probably be April or May and I will probably change to something thicker at that time. Probably 5w30 but I am not sure then. As for the rest of my vehicles I have a Dodge Diesel truck that gets 15w40 Rotella T5 and a pair of track cars.