Any dyno results testing stock cx-5 with various octanes? Saw manual recommended 91 for towing. Is that when output is most efficient, or 92,93?
With gas prices dropping and not driving more than 5k a year Im going to give higher octane a try. Sticking to Shell or Exxon more often than not

 

The maximum rated HP and Torque can only be achieved with the highest available octane.
The ECU will compensate via input from several sensors and load to adjust the engine power to safeguard it using lower octane ratings. This naturally lowers the max claimed power of the engine by Mazda.

No need for DNYO testing to know this commonsense information?

But I have rune a few dozen Chassi Dyno test with accurate Deltas to repeat the operating condition using not only various octane rated by the gasoline distributor but also using specialized high octane fuels as well.

I might add that I also professional and for my own personally vehcle do EFI/ECU Performance calibrating and can see exactly what the Programmers for Mazda Skyactiv gas engines did to compensate for lower octane fuels.

Your choice of sticking with Chevron and Shell is a great idea. I try to use only Chevron but occasionally during trip must use Shell. With my other vehicles most I use the same but for less important vehicle I may use Union 76 and in a pinch Dino. never ever Costco. 7 eleven or the like , and NEVER EVER some weird off brand gas! EVER!

 

I switched to Shell 91 octane (93 not available in my area) about 4 months ago I can definitely see a difference in performance.
I definitely was not expecting it to be so noticeable.
High octane is about .50 cents more per gallon here or about $8 per fill-up.
Well worth in my opinion though admittedly I only need to fill up about once every two weeks, even less in the winter.

 

If you ever get a chance with a good quality scanner plugged into the OBDII diagnostic connector go to the timing PID and leave on live data streaming. You can see that the ECU will advance the timing more for improved throttle response and if you compared it when using lower octane, it will not pull as much timing when doing normal throttling.
Then there is also the CAT F. Here you can see that the CAT will run cooler even up to 100 or more degrees with higher octane fuels.
There are dozens more example to see using a scanner capable of live scanning.

Or get an Ultra Gauge and watch them daily and live as it all happens.

 

Not sure about where you live, but where I live Costco gas is Top Tier, just like the other brand name stations like Shell, Phillips 66, Conoco, etc.

 

Wow , how do you do newbie to the forum Just jump right in a conversation without first starting a thread to introduce yourself? and were so quick didn't read the new member agreement or even take a little time to inter other then the very basic info in your profile speeding right to this thread to respond to defend Cosco or defend your chosen fuel choice?
Ok then! !

Oh and if you looked my signature to the left of every post states Northen California

Joined: Oct 2018
Posts: 10,012
Likes: 164
From: Northern California




Welcome to the forum

Not going to argue with you but they may claim or be on a list unless you see at your location exactly whom their distributer is for their fuel don't know what they are selling you.
"TOP TIER" USA info does not mean and never has meant the best formulated fuel only the quality of the fuel is high standards. The formals (proprietary with better brands names) like Shell and Chevron proven to be about the best) used makes the BIG difference in how you engine performs and how the gas actually helps it maintain efficiency and low problematic issues in the combustion chambers.

I have 2 Costco's less then 20 minutes from my house in CA! Have personally tested over the years both checking specific gravity as well as an only used in the fuel tank on vehicles Dyno'd and they do not perform as well. You don't see anyone professional engine builder or race teams or owner, operators of performance vehicles using Costco fuel in their engine. LOL
And once again if you fill your near empty tank with a brand in your area that is readily available Chevron or shell and re-read my last post you will see at least the best you can what I am stating. Then when you fuel tank is near empty fill with your Costco fuel and re[peat your DIY test and please post your results with a screen shot of the info data from your scan tool freeze frame! And we will talk about your results.
The other point is the internet having to do with Costco fuels is filled with re-worded information yet no real empirical data only what they claim is being said ... sort of like me. LOL But when you do research on where the information is coming from and then try to find more empirical data and information about Costco fuel its almost impossible. Even to find real world controlled unbiassed testing. Again a little like myself .
However, the big difference is you will be hard pressed to find any basic real-world testing and anyone that has run 2 identical engines for about 3-5000 hours on Costco fuels only along with another engine using at least shell or Chevron and then torn down each engine for analysis and observation of findings.
This goes without saying when I owned and Performance engine machine shop, I could generally tell when I teardown an engine performance or stack what type of fuels they used at least if it were Shell or Chevron. I didn't always get it correct when I guessed outside of those 2 which fuel it was and never did, I guess Costco because the engine was never clean enough for me to ever include that as a guess on my part. LOL
So basically, you can personally continue to use Costco that your choice and you may never have a problem with it but if you or anyone else claims Costco is as Shell or Chevron, I hope that can show some data other than the repeated internet information and no empirical information?
You could send in a sample of your Costco fuel to have it analyzed alone with a sample of Shell or chevron. Don't state what brand they are but place a code on each sample. Take a picture of the exact information with handwritten coding take a picture post it and then post the result you returned form the testing source so we can all see and read it and confirm that they are authentic. I am that confident ion my response information about the fuels.


Oh wait I should have asked.... are you an employee, corporate officer or have stock investment in Costco or are you a plant manager at a fuel refinery or engineer fuel formulator? rolmao
I looked at your profile not much there; did you look at mine? Not much there either but maybe IDK a little more than yours ?


Click below it may be an interesting thread for you. Please feel free to post your info it may be interesting for members here to better get to know you?

[url=https://www.mazdaforum.com/forum/off-topic-4/what-do-you-do-have-done-living-44406/]What do you do or have done for a living - Mazda Forum - Mazda Enthusiast Forums




For those really interested one of many suppliers and formulators for Costco fuels is Exon mobile that formulates specific fuel for Kirkland brands for Cosco but it is not their trade marked formula at Exon gas stations.

 

9 Worst Brands of Gas in The United States - Mazda Forum - Mazda Enthusiast Forums

 

Here in North Carolina we do not have Chevron stations or if we do they are far and few between at least where I live. But we do have plenty of Shell, Exxon, and BP stations....all with Topptiergas credentials. We have a couple Costcos as well, albeit too far for me and I have heard nothing but good things about Costco fuel. I wouldn't know I never ran any.

Am I thinking right in believing these toptiergas products (Shell's V-Power Nitro+, Exxon's Mobil Synergy, or BP with Invigorate) are available only in the high octane fuels or are they across all octane offerings? I wanna say Costco offers across all octane offerings, not sure.

 

Agreed, not sure where the Costco hate is coming from. I personally use mostly Sam Club gas in my cars (occasionally Chevron, Quik Trip or Race Track). No difference in my opinion. Car drives the same with all gas. I will go further to say with my 2.5T CX-5 - I never noticed any difference in performance, or MPG with 87 vs 93 octane grades.

 

IMHOP stick with these " Shell, Exxon, and BP stations..."
And to point in fact I never said not to use Costco only its claims or what is posted on the www about them is not exactly fully accurate or to state empirical information pertaining to the formulas used by that brand name of fuels.
There is another very well-respected chemical forum, and they have posted pictures of Cosco's being service fueled from tankers from independent companies. Now while that is not so unusual reading the shipment information is.
If you want the best performance and overall highest MPG then stay with the highest octane available, that you can afford and use longtime branded names. " Shell, Exxon, and BP stations..." naturally Chevron when available