Regular Gas

[Rick's CX-7]

Guys,

Here is my latest report on gasoline grade and the CX-7.

I have been using 89 octane for many several fill ups. I think I've driven at least 2000 miles using nothing but 89 octane....likely much more. The current heat wave affecting the mid section is killing everything in its path....people, grass and trees. We've had sustained 100*F + for quite a few days. If it isn't 100*F, then it's in the high 90s.

The verdict:
1- No audible, noticeable or suspected pingin, detonation.
2- No transmission issues (erratic shifting, slower shifting times)
3- No noticeable or suspected power loss. In fact, engine responsiveness is same or better
4- MPGs are at least the same or better. Just passed the 1/2 tank mark and have driven over 200 miles. This may not sound very impressive, but my daily commute involves climbing all kinds of long-arse hills. Every where I go, the engine has to work extra hard to keep the minimum 60mph cruise-controlled speed. Anyone who's ever been through central Missouri (Waynesville) knows what I'm talking about. Anywhere else and my mileage would be 10% or better.

Lastly, It does get very cold here, necessitating even lower octane, so 87 will be my winter gas.
I believe the slighty higher than sea level altitude and the very rich mixture prevents pingin or detonation even when running 87 octane.

Fire away.....RESPONSIBLY, PLEASE!

 

[bond007taz]

4- MPGs are at least the same or better. Just passed the 1/2 tank mark and have driven over 200 miles. This may not sound very impressive, but my daily commute involves climbing all kinds of long-arse hills. !

OMFG! Want to trade?! When i get to 200 my yellow gas light comes on! Of course, you probably has many more miles on yours than I do...

 

[SuperStretch18]

I hope everything works out for you Rick, but please don't go recommending that others follow your lead. You may be willing to put your new car on the line but most would not and should not...

 

[Rick's CX-7]

bond007,

My best MPGs to date was 29 coming back from Texas. I will most definitely get 300 miles out of this tank before the light comes on.....probably 325 miles.
Also, do you have a heavy foot? That makes a big difference. What's the elevation where you live? Higher elevations require LESS octane since there is less oxygen.
Lastly, I have 12k + miles on my car. Mileage was never as bad as some of the other guys around here though.


SuperStrech18,
I am not recommending anything! Scroll up and read my second to last post.

I am not advocating anyone here disregard the owner's manual. I am simply testing and reporting back. I wish more people would do simple tests like these.

My honest belief is that most of you are not indeed getting the most out of your cars. All factors considered and it is obvious premiun is really not benefiting the engine. But hell, what do I know....I give you Used Oil Analysis, I give you real world experiences and most of you take it for granted. My running of lower octane fuel has nothing to do with saving money. Instead, I am looking for the optimal balance of power and efficiency.
Many of you open your mouths with authority and pass wrong information as fact. Anyone here has a dyno sheet comparing different octanes? Has anyone ran anything other than 93 octane? I bet not!
Well, I've tried to help and add to this community with real data....you can do whatever you want!

chao!

 

[CX-7owner]

Just come back in few years and tell us if that engine is still running.

 

[SuperStretch18]

Don't mind the exact octane numbers, as they are slightly different than measured stateside, but you get the idea.

http://www.thorneymotorsport.co.uk/tuning/Fuel_Test_Results_Update.shtml

The idea that you can get more out of your car by using lower octane fuel is contrary to the definition of octane. Turbo + high compression = needs high octane gas

http://auto.howstuffworks.com/question90.htm

The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.

I appreciate any contribution to the community, but I don't want someone to read this and make the wrong decision. The 2,000 miles you logged are a drop in the bucket; log 200,000 and I will sing a different tune. Or produce some actual data. What is your A/F ration running; take some dyno runs (butt dyno doesn't count); timing advance/retard, etc. Race fuel is hi-octane for a reason.

Re-reading this, I sound like an a$$, but I hope you can take what I'm saying with a grain of salt and hear what I am saying. I don't wish you any ill will and hope that you don't have any issues, but until some solid proof is out there, I stand by my statements...

 

[mikey1981]

bond007,

My best MPGs to date was 29 coming back from Texas. I will most definitely get 300 miles out of this tank before the light comes on.....probably 325 miles.
Also, do you have a heavy foot? That makes a big difference. What's the elevation where you live? Higher elevations require LESS octane since there is less oxygen.
Lastly, I have 12k + miles on my car. Mileage was never as bad as some of the other guys around here though.


SuperStrech18,
I am not recommending anything! Scroll up and read my second to last post.




My honest belief is that most of you are not indeed getting the most out of your cars. All factors considered and it is obvious premiun is really not benefiting the engine. But hell, what do I know....I give you Used Oil Analysis, I give you real world experiences and most of you take it for granted. My running of lower octane fuel has nothing to do with saving money. Instead, I am looking for the optimal balance of power and efficiency.
Many of you open your mouths with authority and pass wrong information as fact. Anyone here has a dyno sheet comparing different octanes? Has anyone ran anything other than 93 octane? I bet not!
Well, I've tried to help and add to this community with real data....you can do whatever you want!

chao!

maybe mazda should hire you for consulting

until you have put on a considerable amount of miles, nothing will be obvious until it all comes out in the wash

 

[Killer]

Guys,

Here is my latest report on gasoline grade and the CX-7.

I have been using 89 octane for many several fill ups. I think I've driven at least 2000 miles using nothing but 89 octane....likely much more. The current heat wave affecting the mid section is killing everything in its path....people, grass and trees. We've had sustained 100*F + for quite a few days. If it isn't 100*F, then it's in the high 90s.

The verdict:
1- No audible, noticeable or suspected pingin, detonation.
2- No transmission issues (erratic shifting, slower shifting times)
3- No noticeable or suspected power loss. In fact, engine responsiveness is same or better
4- MPGs are at least the same or better. Just passed the 1/2 tank mark and have driven over 200 miles. This may not sound very impressive, but my daily commute involves climbing all kinds of long-arse hills. Every where I go, the engine has to work extra hard to keep the minimum 60mph cruise-controlled speed. Anyone who's ever been through central Missouri (Waynesville) knows what I'm talking about. Anywhere else and my mileage would be 10% or better.

Lastly, It does get very cold here, necessitating even lower octane, so 87 will be my winter gas.
I believe the slighty higher than sea level altitude and the very rich mixture prevents pingin or detonation even when running 87 octane.

Fire away.....RESPONSIBLY, PLEASE!

Yea those crazy engineers at mazda are crazy for telling you what gas is best for the cars they manufacture. (hand)

For the life of me I just dont get people like this. Oh well ...good luck.

 

[Rick's CX-7]

OK guys....you win!

Check out this thread: http://www.mazdas247.com/forum/showthread.php?t=123673527

I posted 2 Used oil Analysis and just got one done a few days ago. The amount of fuel in the oil has been "trace", 2.0% and 1.6% over the last 3 analysis. It should be no higher than 0.5%. Also, other owners with MS3s have posted their oil analysis and report exaclty the same....large amounts of fuel in the oil.
With an injector shooting fuel straight into the cylinder and cooling down the chamber, the chances of having pingin or knocking diminish, exactly the reason why Mazda increased compression in this engine. The problem is this thing is tuned super rich, increasing cooling even more and leaving large amounts of unburnt fuel behind. I theorize 89 or even 87 octane can be used without negative effects. This has been mentioned else where and the guy said MS3 and MS6 owners are actually seeing a performance increase. I think 93 could be best used on the very extreme cases, such as Auto-X or the like, where high chamber temps will be much harder to control. For the daily driver and occational dragster, 89 should be ok.

Anyway, all I wanted to do is discuss ways of improving performance. I never intended to get into a pissing contest.....it seems I've been dragged into one. I'll just drop out of this race and leave you all alone.

Rick

 

[Rick's CX-7]

Killer....change your name to ass! It'll fit you better!

 

[CX-7owner]

Killer....change your name to ass! It'll fit you better!

(boom07)(blowup)

 

[SuperStretch18]

(inout)

 

[1Sleepy93]

If I'm not using a good blend of 92 octane I'm getting detonation. (dunno)

 

[Rick's CX-7]

Sleepy,

Is it audible or have you live-scanned the PCM?

 

[Killer]

Killer....change your name to ass! It'll fit you better!

sorry you didn't like my opinion.

 

[AWmustang]

Considering that the premium fuel requirement hurt sales. And considering that it hurt them so much that Mazda is changing engine components and the ECM after 1 year to allow for regular gas.... This all just makes me think that Mazda had a very good reason for requiring premium gas in the 2007 models.

I'm not saying that you are wrong about regular gas in your situation. I'm just stating my reasons for putting premium in my car.

 

[Rick's CX-7]

OMFG! Want to trade?! When i get to 200 my yellow gas light comes on! Of course, you probably has many more miles on yours than I do...

Here you go boond007....taken 1hr ago.




I should be able to get another 30-50 miles out of that 1/4 tank.

Rick

 

[Killer]

Considering that the premium fuel requirement hurt sales. And considering that it hurt them so much that Mazda is changing engine components and the ECM after 1 year to allow for regular gas.... This all just makes me think that Mazda had a very good reason for requiring premium gas in the 2007 models.

I'm not saying that you are wrong about regular gas in your situation. I'm just stating my reasons for putting premium in my car.

Bingo.

 

[mikey1981]

wow thats good, my car would have been coasting into the gas station

 

[Rick's CX-7]

I hear you and understand you point, AWmustang. I can only report on what I've done.....and so far, I haven't had any problems. I'm also running 89 octane.....NOT 87. I did not have any problems with 87 though.
BTW, what exactly was changed parts wise? Pistons, heads, camshafts?

Lastly, for those who have different views than me, let's keep the peace, PLEASE! If you don't agree with what I do, you have the right to disagree and state why. Just don't do it in an offensive manner. I'm too old for any kind of nonsense.

Thanks!