Grade of Gas helped

[Overdrive]

I switched from 87 octane to 89 octane and went from 30 mpg to 36 mpg. Maybe the 89 gas has less ethanol? Makes it worth the cost of switching, imho.

[Aveo5_boy]

I switched from 87 octane to 89 octane and went from 30 mpg to 36 mpg. Maybe the 89 gas has less ethanol? Makes it worth the cost of switching, imho.

For a while I was filling the car with Shell 91 V-power and I definitely was getting more mileage than the regular 87 but not enough to justify the 15 cent (Canada) difference between the 2 grades. Now, I will only use higher octane fuel every once in a while to clean the fuel system but not on a regular basis as it's expensive $h!T. What I do find that helps a bit is the use of Lucas upper cylinder lubricant with every fill but yet again it is a minimal increase in mileage but i do enjoy the quieter engine at idle.

[Overdrive]

The way I figure it. I would have spent $29.99 on 9.2 gallons of 87 octane gas. I spent $27.25 buying 7.9 gallons 89 octane gas. So that saved me $ 2.74 per tank.

That equates to $10.96 per month and $131.52 per year.

[Lefty]

I discovered that in Alberta, all pump gas has up to 10% ethanol with one exception. Hughes gas stations 91 octane has NO ethanol. They are exempted so that consumers have an opportunity to buy ethanol free gas for small engines and such that do not like ethanol. I have found that in summer it isn't worth the cost for a couple mpg improvement, however, in winter, when our gas up here is full of additives causing terrible mileage, it is worth the cost of 91 octane non ethanol.

[AveoJunk]

Overdrive:

Do you believe that octane has an effect on the MPGs? Really?

Aveo5boy:

Do you believe that octane cleans the fuel system? Really?

Octane rating is the gasoline's resistance to self combustion, thats it. higher octane means more resistance. when gas ignites through self combustion, it is called pre-ignition, or knock.

Higher compression pistons will require more resistance to self combustion, hence a higher octane gas needed.

If 89 octane gave 5 more MPGs, they would recommend 89 from the factory and selll the higher mileage. Could have been a number of things that increased your mileage, but it wasn't 2 octane points.

Additives in the more expensive grade may help "clean" the fuel system, but it is NOT the octane cleaning the system.

I am shocked that you guys are on the internet but don't just google this stuff.
A lot of mis-information here.

Maybe one of the repected members here can confirm this. I bet petrified rabbit knows the deal.

[Aveo5_boy]

Overdrive:

Do you believe that octane has an effect on the MPGs? Really?

Aveo5boy:

Do you believe that octane cleans the fuel system? Really?

Octane rating is the gasoline's resistance to self combustion, thats it. higher octane means more resistance. when gas ignites through self combustion, it is called pre-ignition, or knock.

Higher compression pistons will require more resistance to self combustion, hence a higher octane gas needed.

If 89 octane gave 5 more MPGs, they would recommend 89 from the factory and selll the higher mileage. Could have been a number of things that increased your mileage, but it wasn't 2 octane points.

Additives in the more expensive grade may help "clean" the fuel system, but it is NOT the octane cleaning the system.

I am shocked that you guys are on the internet but don't just google this stuff.
A lot of mis-information here.

Maybe one of the repected members here can confirm this. I bet petrified rabbit knows the deal.

AveoJunk:

Take the time to read what I posted again.......When I said higher octane fuels I was refering to the highest grade of gas like supreme, premium, super whatever you want to call the most expensive gas at the pumps & not what octane alone can do. Sorry for the confusion if it came across as sounding like octane alone.

Also it seems you have never tested a full tank of higher octane fuels in your car which I have many times recording mileage as well and "yes" it does give you more mileage than the regular 87 fuel but not enough to justify the difference in cost. 91 fuels contains no ethanol thus the reason for extra miles and the reason why flex fuels give you less mileage....pretty simple to understand. Next time you should do your own personal tests first then give your comments on the matter! Thanks

[Lefty]

The only reason I ever use the 91 octane is because at Hughes gas stations it has no ethanol, not because of the octane.

[AveoJunk]

AveoJunk:

Take the time to read what I posted again.......When I said higher octane fuels I was refering to the highest grade of gas like supreme, premium, super whatever you want to call the most expensive gas at the pumps & not what octane alone can do. Sorry for the confusion if it came across as sounding like octane alone.

Also it seems you have never tested a full tank of higher octane fuels in your car which I have many times recording mileage as well and "yes" it does give you more mileage than the regular 87 fuel but not enough to justify the difference in cost. 91 fuels contains no ethanol thus the reason for extra miles and the reason why flex fuels give you less mileage....pretty simple to understand. Next time you should do your own personal tests first then give your comments on the matter! Thanks

ROFL. Dude, you are all over the place. First paragraph you say read again and say not just octane. Then you say higher octane fuel gives better mileage. Then you say it is because there is no ethanol. BTW many of the US states sell only E-10 no matter what the grade, so more misinformation.

I don't know where you get your information from other than your "personal tests" but you put it out there that higher octane equals better mileage and that simply is not true. You don't have to take my word on it, like I said, Google it.

[freddingo]

From wikipedia:
Many high-performance engines are designed to operate with a high maximum compression, and thus demand fuels of higher octane. A common misconception is that power output or fuel efficiency can be improved by burning fuel of higher octane than that specified by the engine manufacturer. The power output of an engine depends in part on the energy density of the fuel being burnt. Fuels of different octane ratings may have similar densities, but because switching to a higher octane fuel does not add more hydrocarbon content or oxygen, the engine cannot develop more power.

Basically the octane does not determine the amount of energy in the fuel, just how difficult it is to start the burn to harness that energy.

normal compression engine = burn fuel at a normal octane rating (87ish) @ normal altitude.

Compression goes down with higher altitudes, so you can get away with lower fuel ratings the higher you go. Don't ever put premium and then use octane booster when going over a mountain

[Aveo5_boy]

ROFL. Dude, you are all over the place. First paragraph you say read again and say not just octane. Then you say higher octane fuel gives better mileage. Then you say it is because there is no ethanol. BTW many of the US states sell only E-10 no matter what the grade, so more misinformation.

I don't know where you get your information from other than your "personal tests" but you put it out there that higher octane equals better mileage and that simply is not true. You don't have to take my word on it, like I said, Google it.

Once again...."No ethanol = more mileage" not a significant difference but more mileage! It may be useless to argue with you since you have ethanol on all your grades which in our province we don't and probably why you keep harping on the higher octane when it's really the no ethanol.