Hello All,

I know this is a frequently asked question and I've looked at the threads. It seems most everyone says "Full Synthetic is better" and "Check your owner's manual". My wife went to a typical oil change place today and they brow beat her to the point at which she almost thought her 2019 CX-5 would explode before leaving their lot if she didn't use full synthetic. They also took the convenient opportunity to change her oil life indicator to the minimum 3000 miles. Suffice it to say i will never go back to this place. However, I do want to really understand what is truly the PROPER (not saying recommended on purpose here) oil as stated by the manual. I've looked in her paper manual as well as online at https://www.mazdausa.com/static/manuals/2019/cx5/. I can't find the word synthetic ANYWHERE. It also says for "schedule 1" oil changes should be roughly 7500 miles or 12 months whichever comes first (plus or minus based on driving habits if the oil life indicator is set to flexible)

I get synthetic provides better protection and in theory should extend the oil change interval even further but based on my read of the manual for normal every day driving any decent 5W-30 oil "should" be the proper oil for the normal 7500 mile interval. Please set me straight if I'm missing something and sorry for posting such a, pardon the pun, high mileage question...

Manual Excerpt:

SKYACTIV-G 2.5T

Use SAE 5W-30 engine oil.

Mazda Genuine Oil is used in your Mazda vehicle. Mazda Genuine 5W-30 Oil is required to achieve optimum fuel economy.



For maintenance service, Mazda recommends Mazda Genuine Parts and Castrol® (U.S.A. only).



Only use SAE 5W-30 oil “Certified For Gasoline Engines” by the American Petroleum Institute (API).

Oil with this trademark symbol conforms to the current engine and emission system protection standards and fuel economy requirements of the International Lubricant Standardization and Approval Committee (ILSAC), comprised of U.S. and Japanese automobile manufacturers.

 

Ya well welcome to the DIY world of automotive enthusiast forums.
The reason that many owners manual DO NOT stipulate full or Synthetic blend or none synthetic is because in many parts of the world some oil types are NOT available. Plain and simple.
As for viscosity the BIG arguable topic that is also simple, either use what is on your oil cap or the basic information somewhere either on your engine or in the owners manual. K.I.S.S. (keep it simple stupid)

Viscosity choice has to do with a temperature chart depending on engine operation and the ambientes. hat has NEVER changed. But in the world of the internet made experts out of many and lead to confuses practically everyone.
If it is a daily drive in and around FT Worth TEXAS you can without fear of engine dame use a SAE full or synthetic blend in 5W-30 ...10w30... 10w40

NONE of these will effect the warranty on your engine or damage it in any way. You can confirm and contact MAZDA corp and also look into the
The Magnuson–Moss Warranty Act (P.L. 93-637) is a United States federal law (15 U.S.C. § 2301 et seq.).Enacted in 1975, the federal statute governs warranties on consumer products.

Should any member have documented and empirical data and evidence that anything I just posted to be inaccurate please provide that information. Who knows the Laws of physics may have changed with all the Alien sightings lately worldwide. LOL


As for your oil changes I do mine religiously at 3000 miles. But I have several oil analysis performed by Blackstone Oil Labs that always suggest I could go to 5000 miles. (I have read oil analysis that has suggested to some to even go to 7000 miles but not really past that point) For me oil is cheap and has a lot of influence on many performance aspects as well the reliability of the engine. So frequent oil changes is cheap insurance for my investment I have in my cars!
Blackstone Laboratories (blackstone-labs.com)


BTW in my sort of modified Mazda 3 , 2.5 I use several viscosity depending on the season and where I will be driving. Most all are documented on my thread and I have even posted several oil analysis using the different viscosities..

Mazda3 Things I like to do - Mazda Forum - Mazda Enthusiast Forums


While my Mazda is a NA I also own 2 Turbocharged and one Supercharged street driven car.

 

Thanks for the information. Regarding viscosity the cap shows 5W-30 and looking at the owners manual it seems the main benefit of 0W-20 is in colder climates. Even if we did get another Snowmageddon here in Ft. Worth, temperatures below -20F are highly unlikely. I think I'll save the few bucks and stick with the 5W-30 blend. As you said keep it simple stupid....its hard to argue with what's on the cap.

I really wanted to get the recommendation of someone that's not the one trying to sell me the oil. So many of the other threads were "my dealer recommended full synthetic"...my thought was, of course they did! They also recommended the undercoating, extended warranty, and window tinting when you bought the car.

Thanks
Chris

 

Glad to help anytime Chris!!

I am actually getting ready to change and use 0w30 expecting I will not change the oil again until end of December into January. LOL
I just posted this a couple days ago.

We are also flying up to Houston in December to spend the holidays with the family for about 2 weeks. .

 

nice. looks like you're planning on more than an oil change. I have to ask....Is that a Refractometer? What do you use that for? I used to keep a salt water aquarium and we used that to test my new water for water changes. I've never heard of anyone use one on a car? I presume that's for testing the antifreeze. I've always just used those cheap hydrometers. do you find the refractometer more accurate?

 

[QUOTE=cmartin97;207585]nice. looks like you're planning on more than an oil change. I have to ask....Is that a Refractometer? What do you use that for? I used to keep a salt water aquarium and we used
Yes shows the exact % of water to coolant.