We get these threads because Mazda "Rrecommends" Premium fuel and it is not Required.

 

sounds like you have done some research and have proven that premium fuel is not required. Please, show us the results of your research, we are all excited to see how you came to your conclusion.

 

actually on the 09+ it says 89 is required and 91 is recommend.

 

I work at a mazda dealership.

Hear all the info from EVERYONE.

 

working at a mazda dealership is really not an excuse I would advertise when you go spewing random information that you have no supporting evidence to justify your claim..

... a guy that worked at a mazda dealership told me i didn't need to change my oil until 7500 miles too

 

I'm sorry but that doesn't give you any credit. One of our local members was told her clutch blew because her tires were too sticky Another local was told his Mazdaspeed intake could void his warranty. My experience with dealers and their employees knowledge is not good, especially the service advisers and salesmen, they generally talk out of their asses and it is scary. I know my way around and RX-8, I feel sorry for someone who does not that goes in to have a problem fixed. generally dealership seems to diagnose a problem by replacing parts until the problem is resolved.

 

^^ Never said it did.

 

Spewing?

Do you know the difference between recommened and required?

 

When I was racing the RX7, I would go off track to get 87 octane. As long as you have the timing set right, rotaries love low octane gas.

 

They never put a Renesis in an RX-7, so how is this relative?

if your Renesis engine compression sucks then it is no problem

flow muddy Mississippi, flow .....

 

Anyone think their NA 8 will run better using VP C16 instead of C12?

 

and that should end this whole sad thread. the OP is calculating MPG with out knowing how many gallons are being used. he's used a different gas for a single tank at a particular time of the year. it has no bearing on any one else's experience. end of story.

my own experience is that whenever i have tried to run 87 octane i experience knock. I dont remember what times of the year that has been. I can run 89 octane daily driving without any noticeable difference then when running 91 here in Oregon year round. When I drove through Cali a few times I noticed a performance difference between running 89 and 91. the SoCal 89 was like running the Oregon 87. but its also different elevations and different temperatures etc.

your experiences will vary based on your location, time of year and fuel quality(not octane per se)

just to make sure future readers get this- different pump gas octane levels cannot cause the differences in fuel mileage suggested by the OP either with his initial numbers or with his corrected numbers. if your mpg changes that much there is a problem with the car or your driving habits have changed dramatically.

 

130k miles

mpg measured since first driven..

dealer put in 87 right in front of me..

best mpg 25. this was with 87

worst mpg 8.7 this was with 93 (this was on track) i have got 9.3 on track.

you can fight about it, the 87 will give better mpg on the street. now if you are one of those guys that needs coilovers on the street cause you tear it up.

well waste your money..

and the ecu is smart, it might retard spark, and you might lose 2hp.

beers

 

Wow... So you got about triple the gas mileage with 87 octane? Can't argue with that logic!

 

trust me,

the cost in tires, pads, rotors, other. the 9.7 ends up cheap.

but really, the rx8 is a silly cheap track car. unless you are going hard core track you can run this car for just, tires, and track pads.

and still **** every one else on the track..

beers

 

This guy didn't make much sense, but didn't he say he added octane booster to the 87? If you buy $10 worth of 87 for 30 cents less per gallon than 91 then add a $3 bottle of octane booster, what's the point? I have a gas station that sells 91 so I don't have to buy 93 unless I'm out of my area.