I can say on our 21 2.5T, I notice no appreciable difference bewteen 87 and 93. I know it is supposed to have an extra 23hp and 10 ft/lbs, but the car feels just as peppy with 87. I use 93 occasionaly and have not noticed better fuel economy either.

 

You are not suppose to really, because the ECU compensates for the lower octane. But it has limits and once there you may not notice until bad things happen.
If you had an Ultra Gauge you would see in real world values what you say you don’t physically notice .

And I am not sure I would stick by what you read about the power. Spend a couple hundred get your “Turbocharged Mazda” Dyno and join the real world team .
Then if you want to wake up your Mazda go look at and consider the basic Versa Tuner. Once you do and you get hooked we will chat about really waking up the engine

 

I am sure there are plenty of mods to make the engine more powerful. There is a forum member who has done quite of bit to his 2.5T and claims it is more powerful AND has higher mileage. I am holding off on that type of thing until I am betyond the 5yr mark for warranty reasons. Not sure I will even have the CX-5 by then anyway...

 

Ok totally understand.
Yes I read that thread and commented in a response to it.
You as a long-time member and part of the old timer member group here the offer to help you on forum threads or pm (or other ) is always available to you.



Ultra Gauge is transfer able to most all OBDII ECU operating from 1995 to preset systems