Thanks for finding this AAA Premium Fuel Research report. I guess this conclusion from the report should summarize it all:
My biggest question is why the "real-world" horsepower is only about 80% of the rated horsepower on paper? The 3 test-runs for maximum horsepower on Mazda3 Grand Touring 2.0L I-4 which has horsepower rating at 155 @ 6000 rpm are 126.28/126.79/126.54 hp with 87-octane regular fuel and 129.78/129.25/129.52 hp with 93-octane premium fuel. This happens on all 3 test vehicles, a Tundra 5.7L V-8、a Charger SXT 3.6L V-6、and a Mazda3 Grand Touring 2.0L I-4. Why the discrepancy is so huge? (uhm)
So mazdadude, you won't get 188 hp with your 91-octane premium in reality, you can only get 152 hp at most from your 2.5L! (boom08)
126bhp? Really? That's about what an automatic 2002 Infiniti G20 I4 2.0L (I had one) dynoed. Mazda needs to step up. It's not 2002 anymore!