Thats happens with normal gasoline as well. probably not as bad IDK. Also you would have smelled the oil having an issue. His claim changing the oil at 2k miles and no one noticed anything in the oil or filter??
As for the oil choice my guess looking at the actual complete specification and performance information on motor oil in the USA BOTH synthetic, synthetic blend and none synthetic, NO ONE has really proven absolutely that it would make a difference. But that's a BIG argument on forums. I am not saying anymore you can use none synthetic oils anymore mainly because it is readily available and a good price point in the market.

 

Some on the thread have suggested this, but it makes no sense as if it were true, wouldn't Mazda advertise this as they do for the 2.5T?

 

I haven't noticed any difference in performance no matter what grade/ octane of gas I have used in my 2023 NA CX5. I have noticed some brands give slightly better fuel mileage .I always use the cheapest Top Tier fuel I can find ,and that has always been Costco . Fuel prices in Arizona are always higher than the national average .As far as I know all fuel in Arizona has some ethanol in it . I would like to find some pure fuel without ethanol and try it in my vehicle to see if it makes a difference.

 

Yes
All you need to do to see this is connect to your OBDII diagnostic connector and look at the timing, fueling, temperatures CAT and fuel to name the ones PID that will show almost as soon as you change to higher octane fuels.

Its not a SUGGESTION IT IS A FACT. Contact RACING BEAT, CORKSPORT, DIMsport, Versa Tune, and a few others.
While you often question what I post you NEVER do anything actual testing of anything and only get your information from the internet!
In fact anyone in the USA and CANAD, Germany and Australia and England doing Dyno testing can confirm ! Stop sitting on your **** and do some real world testing maybe you would learn a thing or 2?

As fo Mazda we have exhaust the reason why Mazda does not post the best infomratio9n about engine output. They do not want to be responsible for post inaccurate uncertified information as required now in the auto Manufactuing industry . This is another example of your lack of accepting the real empirical information that I often post! rolmao!

Engine Power Test Code - Engine Power and Torque Certification J2723_202110

This document specifies the procedure to be used for a manufacturer to certify the net power and torque rating of a production engine according to SAE J1349 (Rev. 8/04) or the gross engine power of a production engine according to SAE J1995.
Manufacturers who advertise their engine power and torque ratings as certified to SAE J1349 or SAE J1995 shall follow this procedure. Certification of engine power and torque to SAE J1349 or SAE J1995 is voluntary; however, this power certification process is mandatory for those advertising power ratings as “Certified to SAE J1349” or “Certified to SAE J1995.”
In the event that an engine made by one manufacturer is sold to a consumer in a vehicle produced by a second manufacturer, engine certification may be completed by either manufacturer or by both manufacturers working together. An example of the latter would be the completion of witness testing by the engine manufacturer with the submission of certification documents by the vehicle manufacturer.

 

This would be less then correct. You would see higher knock valves under load using lower octane fuels and a lower overall MPG. If not then your testing or computation for results are incorrect.

You can not change physic's sorry !

 

I have long expected the fuel we get in Arizona is weasel ****. As far as testing, I ignore the vehicle dashboard numbers. I fill it up as far as i can, drive until it hits 1/4 of a tank ,refill as far as i can and divide the gallons to miles driven. And that is how i arrive at MPG. I seldom go over 80mph ,and take it easy. I absolutely see no increase in mileage or performance using 91 octane over 89 octane. I average 29.5 MPG if I take it easy ,and drive the speed limit. I live in the valley and it is flat with no hills. I am retired and don't need to rush any place . I have been trying to mend my divers license and not get anymore tickets so I drive the CX5 real easy . My MPG calculations are spot on . I am not doing any jack rabbet starts or 0 to 60 tests ,just taking it easy and going with the flow.

 

Wow thanks for reminding me. I am suppose to get re-certified this year with my Nitrox before we go on vacation.

 

Perhaps you haven't been getting enough oxygen and too much nitrogen when you dive .

 

Ya I dont think so. I dive like I fly, with 100% regards for safety.
I have been flying since 1977 and diving since 1999. Not one accident Diving . Flying one accident not my fault I flip a Cesena 150 when I ran off the runway with failed brake.

 

Maybe the easiest test is just to fill up with a tank of 91 octane, if you don't think there's any difference, just keep running 87. If you can't tell any difference, then it probably doesn't matter.