The performance numbers for the new 3 turbo are listed at 250 and 320 on 93 octane fuel. 93 octane is not sold in Arizona as far as I know. Are the performance numbers for 91 octane somewhere between the numbers for 87 and 93? Thanks

 

The rated power levels are at the engines RED line. The octane simply supports the Turbo Chargers boost levels in which the ECU adjusts for the the increase load via MAS sensor and produced psi of the Turbo, the knock delivered and few other monitored sensors. The Octane itself DOES NOT increase the power output of the engine. Unless you are intending racing your MAZDA and running the engine above 6500 rpm or towing to close it capacity listed I would not worry to much about the octane availability in your area.

Btw way you may be reading THE POWER INFORMATION INCORRECTLY

MAZDA "CLAIMS" the maximum engines output for the Turbo Charged model is 250 horsepower and 320 lb-ft of torquewith premium (93 octane) fuel and claiming with 87 octane fuel
227 horsepower and 310 lb-ft of torque

So really trying to get that extra 23 horsepower is sorta ... well do your really need it???? lol