Premium gas better milage?

[Valk]

Im a car noob, this is my first one so forgive me if this is a stupid question.

I used to burn premium gas in my 02P5 but recently went back to the cheap stuff since prices sharply rose and are gonna keep doing it with canada's awsome eco action plan...

the question is... the car seems to be going through it a lot faster than it used to.. Like... I had a quarter tank left yesterday night. stopped to put $10 in *about 9litres* drove about 8km to get dinner, then 5ish home. drove to work in the morning *15km* and wheni went to get lunch today, the gas light was on. thing was at like 2/3rds of a tank when i put gas in and its empty?

Now the reason i ask this is I definatly wasnt stopping as much on the 91 stuff id put $30 in and it would last all week. I drive it lots too..

bleh. just hope i dont have another problem.. I have a bit of a heavy foot, but since i started using the cheap stuff, i just drive it like an auto should be driven heh.

 

[NCZ13]

the ecu doesnt see octane. its using the same amount of gas whether your using premium or regular. in order to make premium gas useful, you would need a standalone, and have the car tuned for premium. your just wasting your money putting premium in. granted your internals are probably cleaner, but a waste nonetheless.

 

[Valk]

so what would cause it to go through gas so quickly? I know autos are bad for it, but my moms corsica seems to go through it at a better rate that my p5 =(.

 

[bazooka joe]

it could be a number of things....from my experience, a bad o2 sensor will kill your gas mileage! do you have any CEL's?

 

[Valk]

no cels.. i just had it serviced too. or, mazda's preventive maintenance checkup. do they check the sensors on those? or just change my oil, rotate my tires and send me on my way?

 

[bazooka joe]

how is the general performance, engine running okay, is it sluggish, any black smoke when you reall get on it? how many miles on the car?

 

[808MP5]

U don't get more miles on higher octane. Try searching google. There is a good write up on wikipedia

 

[Valk]

might just be in my head but i wasnt filling it up as much it seems. no black smoke on it, seems to run pretty well to me. starting to feel a little raspy compared to when i baught it, but that might be in my head too.
car has 72,800km on it. baught it in november with 68,400 so ive done a fair bit of driving.
when i gun it, it goes, as well as an auto can heh. no complaints there. still wish it was manual *not untill november at the earliest though*

bleh. im sure its fine.

 

[808MP5]

I used to think higher octane gave me better mileage until i did a log on it. Turns out my mileage was the same on either octane. I get 340+ per a tank of gas.

 

[2slow2go]

I used to think the same about the higher octane fuel. But as others said, its just not true.
I do however every second or third fill up put premium in just cause I think its better for the engine.
As for the mileage. It could be a number of things, but depending on where you live, the most likely thing is the climate change. For instance I get about 10 to 15% better gas mileage in the summer than I do in the winter, for obviouse reasons (letting the car warm up much longer, idle runs higher in cold weather).

 

[tripledigits]

The lowest octane you can run without preignition is the octane you should be using.

 

[JD03PR5]

man im only getting about 250 to 285 miles to the tank on my PR5... it seems a tad sluggish on acceleration... after starting the car after driving it for a few miles it will start up and the rpms will drop down to 200 and go back up to the 900-1000rpm range...

o2 sensor?

EGR?

Plugs?

Air filter?

what do you guys think

 

[thejetman]

HIGHER OCTANE = HIGHER ANTI-KNOCK PROPETIES or iso-heptane in gasoline. It means it is a cleaner, more refined, better gasoline. It will help mileage, a little bit, on N/A vehicles. For you guys with a turbo, dial it in with 93 octane, then come to where i work and buy some aviation grade 100LL AVGAS. It will knock your socks off.

 

[ForceFed]

HIGHER OCTANE = HIGHER ANTI-KNOCK PROPETIES or iso-heptane in gasoline. It means it is a cleaner, more refined, better gasoline. It will help mileage, a little bit, on N/A vehicles..

Not neccesarily true...and it might even drop total power output by noit being as efficient of a burn....THe higher the Anti-Knock value, the harder it is for complete combustion to occur.
If your car doesnt require it..your wasting your money running it and may even be rbbing yourself of some power.

 

[thejetman]

Not neccesarily true...and it might even drop total power output by noit being as efficient of a burn....THe higher the Anti-Knock value, the harder it is for complete combustion to occur.
If your car doesnt require it..your wasting your money running it and may even be rbbing yourself of some power.

It is neccesarily true. I work on aircraft, its in every maintenance manual built. approved by the FAA. It burns better, more complete. If you dont need it though, it is a waste. If cars were built on the same basic principles as your average Cessna 172. They would last forever. Of course, that would require annual inspections, and the motor being torn apart about every 2000 hours. Right now i am in the process of build a Turbo-Powered, Turbo-Jet go kart. It uses Jet fuel, which is just refined kerosene.

 

[ForceFed]

No..I am not gonna argue here....Running higher octane will not Neccesarily Net more milage per gallon....Especially if the car is not set up to run on it.
It could result in less MPG and less power to boot from incomplete combustion.

I could care less about your Aviation or maintenance background...It has nothing to do with Octane ratings and how they work.

If your car isn't setup to run on premium fuel..running it is a waste and may actually cause you to lose milage and power...Period.

The higher octane resists igniting and if it resists this much, it can ignite too late in the Combustion cycle which will lead to an incomplete burn and loss of power and performance.

It also tends to burn slower which is one of the benefeits of the higher octane.
If you want the maximum power out of a motor..you want the lowest octane you can get away with without causing pre-ignition...this will lead to the best power and efficiency of your choosen fuel.

 

[thejetman]

No..I am not gonna argue here....Running higher octane will not Net more milage per gallon....Especially if the car is not set up to run on it..It could result in less MPG and less power to boot from incomplete combustion.
I could care less about your Aviation or maintenance background...It has nothing to do with Octane ratings and how they work.

If your car isn't setup to run on premium fuel..runnig it is a waste and may actually cause you to lose milage and power...Period.
The higher octane resists igniting and if i resists too much can ignite too late in the COmbustion cycle whic will lead to an incomplete burn and loss of power and performance.
It also tend to burn slower which is one of the benefeits of the higher octane.
If you want the maximum power out of a motor..you want the lowest octane you can get away with without causing pre-ignition...this will lead to the best power and effiency of your choosen fuel.

lol im not arguing with you. but you wont loss power by using higher octane gas. it dosent "resist" igniting. it ignites at the same temp and pressure. it burns slower, yes. preignition, and knock go hand in hand. usually one is a result from the other. if you dont believe me. run some crap like QT 87 then go get some mobile 93. you will see a defference.

 

[ForceFed]

Ok..Back to your planes now......I think one needs a fill up.

 

[thejetman]

my little A&P cert. trumps all other mechanical certs. out there. i know my s***.

 

[thejetman]

take your cute little 600 to the nearest airfield and put 3 gallons of avgas in there. now, i know you run 93+ octane in that thing right? if not, you are hurting the performance of it. tell me that dosent make a difference. you might have to change your plugs when you are done. but it will run like a champ, and will run sooooooooo smooth. trust me on this one.