BP for some reasons is almost always at least $0.10 more a gallon of the same octane at other places. Kinda crazy. As of now I've been putting 89 in my car because Lincoln, NE is the worst city on the face of the planet and I there aren't even very many stations with 91.

 

sorry to hear

 

im using 76, is it good or bad?
LOL

 

Sunoco Ultra 93. No BPs or Shells near me...

 

I try to use BP or shells and always 93

 

Shell Gas FTW. Even though its about 0.20 cents more expensive here... 93 vpower!

 

I only put 93 in my car
Vpower when ever i can and i avoid small privately owned gas stations at all cost... a small gas station in my town was found to be watering down there gas and was fined heavily for it

 

Our cars will probably run on the lowest octane you can find anywhere (I'm hoping the 76octane person was kidding??) and you won't notice knocking as computers will notice the knock before your ability to ever think you heard it, BUT that means that the timing is being retard to compensate for the knocking. Throw your car on a dyno next to a car with 91. I am certain that the retard in timing is enough to throw out low HP numbers as well as bad fuel economy and unburnt hydrocarbons. I'd be curious if you hear noise in the high rpms especially redline?
Mazda put the research in and trust me if they don't have to put "premium Unleaded only" stickers they won't. That hurts car sales.

 

I'm guessing he was talking about the 76 gas station, not 76 octane.

 

When going from 93 to 89 to 87, I notice very little difference during normal (highway) driving (8500+ rpm tended to be a bit less fluid with 87)...but I haven't noticed any loss in HP. The only other difference I've observed is that I get an extra 20-30 miles per tank with 87...however, this is probably attributed to my driving characteristics when I fill up with 93. I put V-Power in every once in awhile because I buy Shell's claims about extra detergents being beneficial. Accordingly, even when using 87 I'd rather pay the extra two or three cents per gallon at Shell. I can't say I'd use 93 for daily driving, based on what I've observed. As always, mileage may vary.

 

The only reason I use 93 Octane is as a barrier of insurance for my engine; however, I may eventually go back to 91 for loosely explained reasons below.

I do not claim to be knowledgeable in the subject, but my basic understanding is that there is no benefit to higher octane than the manufacturer recommends other than resistance to detonation. Whether higher octane fuels (100+ or possibly race-specific) may have properties that provide more power is unknown to me, yet this resistance property is THE definition of the *octane rating*.

Detonation involves at least two factors: compression and heat. For one, we know that the Renesis runs at a relatively high compression rate of 10:1. I would presume the reason many are able to safely run with lower octane than recommended is because they are using it in a climate within lower tolerances of what Mazda considers to be the upper range of operating temperatures the cars will see globally in conjunction with the high compression. (eew; sorry about the run-on) Interpretation - 91 octane recommended is Mazda covering their *** in saying it is the global safe octane number to normally run the car in any temperature environment. As an aside, I am wondering how many people run lower than 91 octane gas on the track in temperate climate zones (90 degrees-ish) without problems.

I kinda lost my train of thought with this and hope my blabbering is sufficient for whatever point (if any) I was or was not trying to make. (I am half-expecting a big " WELL DUH!" or something worse from a particular crowd of people )

 

I've always just used V-Power in all my vehicles...

 

I looked for some sort of sticker on the pump yesterday to tell me Ethanol %, but didn't see one. Is there another place to find out, or just ask whoever works inside assuming they even know?

 

In PA, DE, MD, VA (all the states I drive in regularly) the ethanol sticker is on the pump. I'm not sure what the deal is in Texas however, so this probably isn't very helpful. If your state doesn't require ethanol, it is possible that there isn't any in the gas (Some people say they can still get VPower without Ethanol)

 

sunoco always uses 10% ethanol around me and if its in there they have to show it if no sticker than no ethanol and 10% i think is the max they are aloud to use. and i have used 87,89,and 93 in mine and notice a change in the miles per tank i get but i do notice a difference in stop and go driving not on the highway though but i usually go with 93 only ran lower one time on a long drive and around town to finish the tank off. and sometimes get i believe is 104 from speedway when i plan to drive hard

 

Sorry to bring up an old thread.

What do you guys think about 90 octane?

I am talking about Husky with 90 octane. Husky has 90 octane same price as all other gas stations in my area selling 87 octane. it's very close to 91, but priced at regular. That's like 12~13% saving but pretty close to required octane....

 

I use Shell V-Power

to answer your question: it really doesnt matter. 90 is close enough to 91 which is recommended. Even then, you dont NEED 91 octane. People will fill it at 87 and it will still run. 91 is just better for the engine

 

I just realize husky has 10% ethanol. That's why it's cheaper for higher octane. The maximum ethanol on owner's manual states 10%. That means it's right at the maximum ethanol.

hmmmm..... suddenly it doesn't sound as attractive anymore.....

 

sometimes its best to pay a bit more for better quality

 

I pull into BP, Shell, or Sunoco and pull out the respective credit card. Roll down the window, pop the gas door.


Hand them the credit card and say fill up 93.


The manual claims 91 octane. But the only station around me sells 91 for $.05-$.15 cheaper than 93. So I just go for the major companies and get 93. I have had limited issues with my car by gas related.


I'd recommend throwing in BG44K every couple of months (can be purchased from Rosenthaln Mazda) It cleans the fuel system, giving you a better smoother ride.

 

^ I also put in Idemitsu Premix (4oz/fill up) every time. Helps especially at high RPM's.

 

So it's E10 gas. hmmm.... they have E10 with 94 octane in husky also a little cheaper than others...

Any one can explain me more about E10 on our 8? Some Shell and Chevron also sells E10, right?

 

i like to use 76, or chevron with techron!

 

great thread, thanx for bumping it

 

Chevron w/ techron all the way! Wish I could find something higher than 91 oct here in cali