Mazda 6 Forums banner

21 - 40 of 457 Posts

·
Registered
Joined
·
1,769 Posts
I get about 3 miles per gallon less on 89 (10% ethanol) then I do on 87 on average. Ive done 3 tanks on each and the results are consistant 16-16.5 on 89, and 19-20 on 87. I've also noticed that it seems as though i get a bit more pull in the low rpms with the 87. I did 2 tanks on 91 and nothing changed between that and the 87 so I quit "testing it" as it was ~ $4-5 more per tank of gas. I havent raced it though so go fig. If i do ill use 91 probably. There is a gas station that sells "120" racing fuel.. lol, but i have yet to test this. Seems kind of pointless anway and it was well over $3 per gallon last year.
 

·
Registered
Joined
·
788 Posts
I get about 3 miles per gallon less on 89 (10% ethanol) then I do on 87 on average. Ive done 3 tanks on each and the results are consistant 16-16.5 on 89, and 19-20 on 87. I've also noticed that it seems as though i get a bit more pull in the low rpms with the 87. I did 2 tanks on 91 and nothing changed between that and the 87 so I quit "testing it" as it was ~ $4-5 more per tank of gas. I havent raced it though so go fig. If i do ill use 91 probably. There is a gas station that sells "120" racing fuel.. lol, but i have yet to test this. Seems kind of pointless anway and it was well over $3 per gallon last year.
[/b]
The by-product of poor gas milage with 89 compared to 87 is "performance" ... I think it was car and driver that stated our cars are "thirsty" and have "...gas guzzeling performance" ... there you have it ... poor gas milage on the 6s = sweet spot performance!!!
 

·
Registered
Joined
·
1,127 Posts
yea they say compression and all that affects it..however

my engine has the same bore, stroke, compression as my brother's maxima

his is reccomended for high octane fuel


crazy
 

·
Registered
Joined
·
165 Posts
yea they say compression and all that affects it..however

my engine has the same bore, stroke, compression as my brother's maxima

his is reccomended for high octane fuel
crazy
[/b]

bore, stroke, and compression are not just the only factors.

What do you drive, anyways? And which maxima are we referring to?

What about spark timing and all that, that's very important as well.
 

·
Registered
Joined
·
308 Posts
Hi, im just wondering what octane gas I should use. In the owners manual is says to use 87, but to my knowledge isn't 91 always better. 91 octane is supposed to be for, correct me if im wrong higher compression motors. So does the V6 mazda 6S motor need 91 or is it just a waste?

I also know if the motor is supposed to use 91 and you use 87 it will throw on the "check engine" light, because the emissions sensor will read incorrectly if 87 is used. I'm currently using 91, but I really dont want to waste money if its not going to really matter.

Thanks!!!!!!!!
[/b]

Here is a link to help you decide for your self. Link for octane (gas) knowledge. Tell me if this helps.
http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm
 

·
Registered
Joined
·
24 Posts
lol, here in Germany the lowest octane we have is 92. We have 92, 95, 99 and 100. And for the 4-cyl we have to take the 95 minimum.
 

·
Registered
Joined
·
4,791 Posts
lol, here in Germany the lowest octane we have is 92. We have 92, 95, 99 and 100. And for the 4-cyl we have to take the 95 minimum.
[/b]
Somebody correct me if I'm wrong, but I believe the way Germany rates their octane levels is different from the way that North America rates octane. If so, your 92 is not the same thing as our 92. ;)
 

·
Registered
Joined
·
15 Posts
According to mazda's website the minimum octane rating should be 87. That is what they veiw as regular unleded. :nana:
 

·
Registered
Joined
·
1,759 Posts
just my .02

i was using super 91, and 93 octane when i first got my car....it was expensive...but whatever my MAZDA6 deserves the BESTTTTTTTTTTTTTTT right!???????

WRONG.

This car was built to run on regular unleaded, anything above that is a waste of money and serves no real purpose. Using a higher octane gas will not increase gas mileage, it will only burn quicker because it is a higher grade. Our Engines in these cars DO NOT carry a high combustion rate which needs the premium, or super gas....

so to put an end to all this talk.....REGULAR is the way to go, anything else is just STUPIDITY.

and about your car running better on super...its all in your head....
 

·
Registered
Joined
·
124 Posts
If you want to use Ultra 94, knock yourself out. All I can say is good luck with a warranty claim if you have any engine problems. Each engine is designed to run on a specific octane. Mazda was nice enough to design it for 87 :)
 

·
Registered
Joined
·
29 Posts
I mostly use 87, but every once in a while Ill "burn out the crap" with some 89 and a bottle of injector cleaner. It seems to work. When I was in high school, I had an 1985 V6 Camero, and I worked at the local airport. Once a month, I ran the tank almost empty. On the way to work, I would stop and put half tank of the best gas on the market. Then, once I got to work, I filled the rest of the tank with 100 low-lead avaition fuel!!! WOW!!!!! I tell yah, the tank only lasted a couple of days, but damn, it would take off like a rocket! Only thing was, it was a little smelly, and I had to replace the plugs once a year. But, it was alot of fun! Of course, that was beofre all the fancy compterized emissions systems. Can you imagine doing that to todays cars? HAHAHAH!!!!!!!
 

·
Registered
Joined
·
489 Posts
I mostly use 87, but every once in a while Ill "burn out the crap" with some 89 and a bottle of injector cleaner. It seems to work. When I was in high school, I had an 1985 V6 Camero, and I worked at the local airport. Once a month, I ran the tank almost empty. On the way to work, I would stop and put half tank of the best gas on the market. Then, once I got to work, I filled the rest of the tank with 100 low-lead avaition fuel!!! WOW!!!!! I tell yah, the tank only lasted a couple of days, but damn, it would take off like a rocket! Only thing was, it was a little smelly, and I had to replace the plugs once a year. But, it was alot of fun! Of course, that was beofre all the fancy compterized emissions systems. Can you imagine doing that to todays cars? HAHAHAH!!!!!!!
[/b]
This is a really funny thread. There's so much misinformation here about the perceived advantages of higher octane fuel.

The below is copied and pasted from this link (http://www.ftc.gov/bcp/conline/pubs/autos/octane.htm) that was posted earlier:

The Low-Down on High Octane Gasoline
Are you tempted to buy a high octane gasoline for your car because you want to improve its performance? If so, take note: the recommended gasoline for most cars is regular octane. In fact, in most cases, using a higher octane gasoline than your owner's manual recommends offers absolutely no benefit. It won't make your car perform better, go faster, get better mileage or run cleaner. Your best bet: listen to your owner's manual.

The only time you might need to switch to a higher octane level is if your car engine knocks when you use the recommended fuel. This happens to a small percentage of cars.

Unless your engine is knocking, buying higher octane gasoline is a waste of money, too. Premium gas costs 15 to 20 cents per gallon more than regular. That can add up to $100 or more a year in extra costs. Studies indicate that altogether, drivers may be spending hundreds of millions of dollars each year for higher octane gas than they need.

What are octane ratings?
Octane ratings measure a gasoline's ability to resist engine knock, a rattling or pinging sound that results from premature ignition of the compressed fuel-air mixture in one or more cylinders. Most gas stations offer three octane grades: regular (usually 87 octane), mid-grade (usually 89 octane) and premium (usually 92 or 93). The ratings must be posted on bright yellow stickers on each gasoline pump.

What's the right octane level for your car?
Check your owner's manual to determine the right octane level for your car. Regular octane is recommended for most cars. However, some cars with high compression engines, like sports cars and certain luxury cars, need mid-grade or premium gasoline to prevent knock.

How can you tell if you're using the right octane level? Listen to your car's engine. If it doesn't knock when you use the recommended octane, you're using the right grade of gasoline.

Will higher octane gasoline clean your engine better?
As a rule, high octane gasoline does not outperform regular octane in preventing engine deposits from forming, in removing them, or in cleaning your car's engine. In fact, the U.S. Environmental Protection Agency requires that all octane grades of all brands of gasoline contain engine cleaning detergent additives to protect against the build-up of harmful levels of engine deposits during the expected life of your car.

Should you ever switch to a higher octane gasoline?
A few car engines may knock or ping - even if you use the recommended octane. If this happens, try switching to the next highest octane grade. In many cases, switching to the mid-grade or premium-grade gasoline will eliminate the knock. If the knocking or pinging continues after one or two fill-ups, you may need a tune-up or some other repair. After that work is done, go back to the lowest octane grade at which your engine runs without knocking.

Is knocking harmful?
Occasional light knocking or pinging won't harm your engine, and doesn't indicate a need for higher octane. But don't ignore severe knocking. A heavy or persistent knock can lead to engine damage.

Is all "premium" or "regular" gasoline the same?
The octane rating of gasoline marked "premium" or "regular" is not consistent across the country. One state may require a minimum octane rating of 92 for all premium gasoline, while another may allow 90 octane to be called premium. To make sure you know what you're buying, check the octane rating on the yellow sticker on the gas pump instead of relying on the name "premium" or "regular."
 

·
Registered
Joined
·
489 Posts
Adding to the information provided by the FTC above, higher-octane fuel is blended to burn slower than lower-octane fuel. At some level of compression (and temperature), all octane grades will spontaneously detonate (without an ignition souce, such as a spark plug). Higher-compression engines and those with higher combustion-chamber temperatures require higher-octane fuel so that the mixture doesn't combust before the spark ignites the mixture. This is called detonation, or knocking. If left unchecked, it can destroy an engine because the fuel combusts during the compression stroke, instead of the power stroke. This results in excessive pressure inside the cylinder that exceeds the compression-ratio limits of the engine, and BOOM! something breaks. Most modern engines have a knock sensor, which detects detonation and retards the timing to prevent engine damage.

On very hot days when the intake air temperature is very high and engine loads are high, an engine designed to run on 87 octane may have detonation (due to high combustion chamber temps). When this happens, mixing in a few gallons of 89 or 91 can reduce detonation. Otherwise there is no advantage to using higher octane in engines not designed for it.
 

·
Registered
Joined
·
123 Posts
Anyone have any luck with 10% ethanol gasoline?

The reason i ask, is because ethanol gives you a higher octane. So 87 Octane regular cost the same as 89-91 octane ethanol. So you pay the same, but you get a higher octane rating.

Now, higher octane could give you worse gas mileage, and have no benefit in performance. But is it bad for the engine?

Since i live in Wisconsin, so most gas station now have 10% ethanol in all their fuel. Certain gas stations don't use ethanol. So should i be selective to which gas stations i go to?

if its the same price, i would go for whatever is closest or most convenient. But i don't want to lose 2-3 mpg or do slight harm to my engine.

i have a 4cyl btw.

Just curious.
 

·
Registered
Joined
·
123 Posts
Kwik trip started putting Ethanol in their fuel. Their REGULAR and PREMIUM were both the same price. Higher octane in the Premium for the same price. Couldn't figure it out, until i realized that the Premium had ethanol, and the regular didn't.

Also the E85 ethanol station had 10, 20, 85% ethanol fuels. The 10% was 89 Octane and was 5 cents cheaper than other gas stations with regular fuel, 87 octane.

So maybe it depends on the gas station. I know their is probably a law in Wisconsin that gives tax breaks to those stations that use ethanol in their fuel. Considering it burns cleaner, and is cheaper than gas, because we are in a corn producing state.

So they probably deduct state taxes on each gallon for ethanol, just to promote its use. But who knows.

I will just stick to picking the cheapest gas from now on, no matter the octane rating. Maybe i will do some tests to see which is better or worse.

btw.. some cars actually get better gas mileage using ethanol fuel, it depends on the make of your vehicle, no clue how the 6 rates...
 
21 - 40 of 457 Posts
Top