Do you really need 93 Octane?

[Blendercloud]

I only use Rotella T-Syn 5w-40 in my MS6. It's pretty cheap, but it also has shown over multiple oil analyses to hold its properties better than the Pennzoil, Mobil, Royal Purple, Amsoil counterparts. In the end, as long as you change the oil regularly and aren't using something ridiculous like straight 50 weight, you'll be okay under normal driving conditions.

By using an 87 octane in place of 91 or 93 (depending on year) it is much more likely that you will have issues with detonation and trigger the knock sensor. When the knock sensor detects detonation, it tells the ECU to reduce the amount of ignition timing that is advanced (lowering horsepower produced). By using regular, you will likely notice poor fuel economy. Additionally, you may also experience detonation causing damage to piston surfaces or bending/breaking connecting rods (although less likely).

 

[8.5MS3]

New 2010 CX-7 Turbo owner... The manual states Premium gas but, the 2010 brochure states "Regular unleaded (for maximum performance, premium unleaded is recommended)".

I wonder what that means exactly... How is HP & torque effected? What damage would using Regular cause?

Anyone recommend which oil to use? I'm a long-time user of Mobil-1.

follow the manual, high compression + boost = very prone to knock if crappy gas is used. the motor will retard timing, and reduce boost to combat the knock, reducing power. If the knock is bad enough, it can send the ecu into a "limp mode", to protect itself. I believe the MS3/MS6 is a bit more agressive in its tuning, so you probably have a wider margin before hitting these type of issues, but better safe than sorry. Its really only a few bucks per tank. cheap insurance imo. I recommend penzoil platnium.

EDIT: damnit blender...way to steal my thunder

 

[jimkiler]

New 2010 CX-7 Turbo owner... The manual states Premium gas but, the 2010 brochure states "Regular unleaded (for maximum performance, premium unleaded is recommended)".

I wonder what that means exactly... How is HP & torque effected? What damage would using Regular cause?

Anyone recommend which oil to use? I'm a long-time user of Mobil-1.

Per newspaper articles I have read all cars have to be able to run on 87 octane in the US. You might lose some horses but that is why it says recommended and not required.

 

[Tungsten6]

I remember reading a post on an acura forum.

the guy switched to reg for like a month and he got like 26 or so mpgs with regular and 27-28 with 93.

so your going to end up spending more money on the reg when you think your saving money..

goes go for the 93. its not that much anyway. (try driving a ms6 when gas is 4.00+

 

[offset_98]

Remember all....the EXCEPTION is for the 2007 MY CX-7. You MUST use 91+ on that year. The ECU does not recognize anything less!!!

 

[mitchntx]

follow the manual, high compression + boost = very prone to knock if crappy gas is used. the motor will retard timing, and reduce boost to combat the knock, reducing power. If the knock is bad enough, it can send the ecu into a "limp mode", to protect itself. I believe the MS3/MS6 is a bit more agressive in its tuning, so you probably have a wider margin before hitting these type of issues, but better safe than sorry. Its really only a few bucks per tank. cheap insurance imo. I recommend penzoil platnium.

A little late, but .... (attn)

One variable not listed though is temperature of the air charge. If you live in a hot climate, then higher octane fuel is a must in order to protect the motor. You can't 100% rely on the ECU to protect it for you. If it's bad detonation, by the time the ECU pulls timing, skirts and ring lands may've already been damaged.

If you hear that tell-tale rattle noise coming from the engine, typically under hard acceleration, then let off the gas till it goes away. Then get some higher octane in it ASAP.

 

[Greats2]

I use mid-grade 89 seems to do the trick for mine.

I also have the non-turbo version.

 

[bachman]

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Here in Colorado we have 85, 87 and 91 I think. I found one place in town that offers 93 if that info is still current. I haven't had our CX-7 long enought to run much over one tank yet.
I think I'll stick with being safe and run the better juice. In my other car, I tested the mid and high grades and found what some others posted; Cost benefit of going up in octane was paid off in mpg yeild. That was my experience in a 3.5l Nissan motor in a car that doesn't set any mpg records either.