rsilvers129

I find it fascinating that Mazda has an engine which makes more power with 91 and less power with 87, and they recommend 87, and most people probably use 87 with it. And Audi has an engine that also makes more power with 91 and less with 87, but they chose to recommend 91, and so many people wouldn't dream of using 87 because it is not "recommended." There is no difference in how the engines handle the different fuels. The difference is what each company chose to put in the manual, and it completely changes how people react.

VW also did what Mazda did - they recommend the lower fuel even though it is actually designed to work better with the premium fuel.

jrtouareg

Here's the youtube link of the Mazda engineer explaining how the CX-9 2.5 liter turbo works. He describes about a minute in the 227hp - 250 hp depending on the grade of fuel you use.

jrtouareg

Makes me feel guilty driving my Q7 which cost $33K more than the wife's fully optioned CX-9. And having driven both, they handle very similarly. Both very quiet and composed. Getting back to fuel mileage, the CX-9 is getting about 18-19 in suburban driving and 23 mpg on the highway as long as you drive below 77mph. My Q7 has less than 2000 miles and I'm getting about 16 suburban driving and 22 highway. Hopefully I'll get at least EPA rating when its broken in. CX-9 0 - 60 is 7.8 sec, Q7 is 5.7 sec., which means I paid $16.5k per second. Wow.