Curious as to why Mazda does not use full synthetic oil for theCX-5's? I'm guessing it's a cost thing?

 

I bet if you follow the mileage timelines any oil\ filter would be just fine- I remember running normal 5w 30 oil on my cars and never had any oil related issues (no mater what make)

 

Except for turbocharged engines, I don't see much need for synthetic oil. It does reduce coking in really hot areas, like turbos, but I've seen the old green bulk oil in glass jars do just fine. Especially since the refining processes now really make the oil clean.

 

Not sue what you mean. IIRC, Mazda uses syn oil as factory fill. The "OFFICIAL" Mazda oil is made by Idemitsu IIRC. It's a high moly synthetic.
What a dealer puts in after that is up to the dealer and the owner.
Dealers carry synthetic oil in both weights/grades Mazda calls for. Owner's choice if they bother to ask.
I do my own so I know what is in there.

My 2¢

 

You are correct, Dennis. The reason why I was confused was I had called the dealership where I had my first oil change and the service person said it was not synthetic. When I looked at my service receipts for the 3 oil changes 2 were synthetic - Mobile 1 and "SUP PR MTR OIL" (first oil change) was not a full synthetic.

 

Yep- mine say synthetic as well...

 

It's possible the first change was break in oil. Usually, the oil put in when it's rebuilt is the break in oil. When I quit rebuilding engines myself, I wouldn't use synthetic for break in oil as it was too slick. The rings wouldn't seat. The last engine I did ate a quart of oil in the first 50 miles. After that, oil changes every 3000 miles and it didn't use hardly any between changes. Once the rings were seated, I went with synthetic. I usually never went back to regular once I went synthetic. I found internal rotational inertia easier to overcome with synthetic.

 

From what I can determine Mazda Super Premium 5W-30 is not a synthetic oil yet at my first complimentary oil change for my 2021 Mazda 6 GTR the dealer shows it as full synthetic. Even the tech who I talked to says it is although I did not witness the actual oil change. Now personally I do not get all worked up over which brand is best,you must use full synthetic and blah blah. Mazda recommends 5W-30 for the 2.5 turbos in the manual but there is no mention of synthetic and no where on the bottle does it say synthetic oil that I can see. The curious part is when I got home and looked at the invoice they show it as costing $4.13 x 6 quarts and just a little over $55.00 for the oil service with new Mazda $6.81 filter.(I guess they show billing amounts even with a complimentary oil change.) Seems like it would be pretty cheap at $4.13/ qt even for regular non-synthetic oil. Anyway my bigger concern will be keeping an eye on oil levels in light of the TSB issued by Mazda for 2021 turbos and oil consumption. So far so good after 1st oil change at 2500 miles.

 

Ok so what the heck were you using for your final hone finishing, the tool and the procedure? And a quart at 50 miles.....wow!!!!!!!! I have never in my life on any rebuilt engine of any kind had that happen??.
I have never experienced that form any engine I built. LOL When I first started to read you post I thought you were going to say you used none detergent oil for the break in? That was a practice thought to be acceptable from some real old timers like pre 70's that carried into the 70"s and even as late as early 80's.

The break in of rings seating is directly related to the finish hone and type of rings used. Also during the break-in the need for building pressure in the mechanical aspects of the rings forcing them to wear into the cylinders walls or you would get a glaze. The motor oil if it was none detergent, conventional motor oil or semi and full synthetic had almost nothing maybe negligible support one way or another regarding the break in of a new engine and rings seating properly? Just saying! LOL

Please do not take offence.

I mainly built Performance engine and many of them I had to run up on my engine DYNO and do a pre-break in before I delivered to my customers with a DYNO run indicating the exact power output. So, your post just made my smile a bit while drinking my coffee this morning!
I should also mention that during the time period because of the cost of engines and I didn't want to rebuild an engine I built because of some over sight the oil during the break in was sampled and analyzed through Blackstone labs and that report was also part of the delivery engine information. These engine varied between 15K to 30K respectably

 

50 miles during break in isn't unusual. Engines often use oil when seating the rings. As for the honing or bore procedure, I have no idea. I let the machine shop that did my engines when I was racing, do the work. When I changed the oil at 500 miles, I cut the oil filter open. I put large ceramic magnets on the filter housing while it was breaking in. There really wasn't much ferrous build up inside it. I scrubbed the bores and lifter runs repeatedly until the rags came out clean. Most people don't do that, at least not as often as I did, but I knew what the engine was going to do so it was spotless after machining. That also means there was no honing residue left from the machining.

Keep in mind, Detroit doesn't consider oil usage excessive until it's a quart in less than 800 miles. I changed the oil on that engine every 2500-3000 miles. It didn't use a drop between changes. The quart in 50 miles was the only oil it used.

Keep in mind, you are today. This was 30 years ago. The car is still running although I doubt it is pushed as hard as I did when I built it. I nearly lost my license in it.