In the USA with the easing up of the EPA regulation the adjustments in the ECU can actually create an improved MPG even with the increase in weight.
In reality a ECU programing like Versa Tuner on any Mazda they offer you can improve both power and MPG and still be under the EPA requirements for the time before the EPA regulation were just reduced.
I created a couple of specific target ECU files that do just that and are under the HC and CO readings at the tail pipe that could easily pass any states tailpipe test.

But you all will have to wait for a little longer because no one offers' a program yet for the newer Mazda's CX-5 with CD 2018-2026
VersaTuner

 

i find posting "welcome to the forum" in a first post where a user is looking for info to fix their car a waste, but i guess it helps pad the post count...ahh yes courtesy, courtesy must be why you've been booted from other vehicle forums by admin/mods...funny that you think i would actually spend the time to search and count the actual number of times you welcomed people lol...but i'm sure that most people agree with you that car dealerships trustworthy lol...anyway, carry on denying reality about i-stop and cylinder deactivation being installed on the 2026 cx-5

 

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