looking at a cx7,question about gas mileage and octane?

[carlos_hathcock]

I bought my sisters 07 CX7 i is by far one the best vehicles I've driven so far. It has 28k miles on it so far we took it to the dealer because of some noise it had, it sounded like a diesel engine, and when you started it sounded like someone was raping an alligator (just trying to exagerate here). The service supervisor was a real dick head, but once i found out he was in the service I told them I'm still in the military and that was my ice breaker, the car had a problem with the variable valve timing actuator, the timing chain tensioner and i don't remember what else. I asked him specifically about the 87 octane and he said quietly (between you and me, 87 is just fine, and after doing all this recall work, you shouldn't have a problem, the 91 octane is just for them to give a reason to not honor warranties). So that's what he told me. I trust the guy, and looking at his wall from all his awards and certifications, i can be comfortable following anything he says. Also a mechanic who doesn't try to upsell you anything you really don't need is great in my book.

 

[carlos_hathcock]

WTF? Over...

 

[JGreen215]

2008 cx-7

I'm buying a 2008 GT AWD this weekend. I can't wait.

 

[Zoom49]

I asked him specifically about the 87 octane and he said quietly (between you and me, 87 is just fine, and after doing all this recall work, you shouldn't have a problem, the 91 octane is just for them to give a reason to not honor warranties).QUOTE]

I believe he gave you wrong advice, for the 2007 models 91 octane was manditory. They changed the PCM in 2008 to allow use of lower octane fuel.
There are numerous reports on this forum of owners with engine knock on 2007 models even when using 91 octane. My 07 had the PCM replaced due to
numerous trips to the dealer with severe engine knock even while using premimum 91 octane. If yours was a 2008 you could substitute 87 or 89 octane with lower performance.

 

[offset_98]

Yeah, DO NOT use less than 91 in your '07. You're only asking for trouble. If you do and something does happen, I'll tell you now, that service adviser will deny what he said to you until the day he dies.

 

[erhayes]

I believe someone is misinformed that it is only a software re-flash to enable an 07 to run 87 or 89 octane safely. Mazda has stated in emails to others that there are some mechanical changes in addition to software changes (not just a re-flash) on the later model years. I have tried my 07 (with all latest re-flashes) on 87 & 89 octane. 87 was a lost cause from the first block. 89 seemed to run OK at light or medium throttle but, when exiting a corner in 3 d gear and pushing it, I got the death rattle and the computer shut the engine way down-not a safe thing in traffic. I now use and recommend that 91 or higher, like the factory requires be used.