High Octane fuel

[commonlaw]

I have a 302 and since buying my EB about 6 months ago, I have always put the best octane in my beast assuming that, even if negligable, I get some benefits of engine life, etc? Am I way off and I should just throw the regular unleaded in there? Would it make a difference that my truck is used to the good treatment if I went back to the lower octane? Thanks guys

Mark

 

[DownhillManiac99]

I run 91 in mine 90% of the time I fill up, a few times Ive mixed in a gallon of 100 octane just for the smell which probably isnt very smart on a roughly stock 302. With gas prices now Ill drop to 89 once a month and it doesnt make a difference. I use mine as the high school daily driver by the way.

 

[commonlaw]

I run 91 in mine 90% of the time I fill up, a few times Ive mixed in a gallon of 100 octane just for the smell which probably isnt very smart on a roughly stock 302. With gas prices now Ill drop to 89 once a month and it doesnt make a difference. I use mine as the high school daily driver by the way.

Damn, I wish I had my ride in HS...had a harder time pullin ladies in the Tempo (at least it was a Ford and had red velvet interior). Thanks for the comments.

 

[fitpays]

from what i understand, octane rating is a gasoline's resistance to knock and ping. if you dont have any knocking or pinging, and of course, if you dont have major engine mods -regular unleaded is fine. later on, if you add a cam or higher compression smashers, worry about some high octane then.

 

[Nobody]

Octane slows the burn of the fuel. It makes the fuel more stable so it doesn't detonate before the spark (pinging). The higher compression ratios require higher octane fuel. If you don't have problems with pinging/knocking, you're throwing your money away.

 

[76Broncofromhell]

I run 91 only because I HAVE TO. When I had a stock 302 I never ran anything over 87 so you are just wasting your money. If it isn't pinging, drop another octane rating. My guess is you could get away with running 87.

 

[commonlaw]

So the consensus is that if it aint pinging, no point for higher octane. No other benefits?

 

[76Broncofromhell]

Unless you consider making the Saudi's and the rest of OPEC rich a 'benefit'. Putting higher grade fuel than needed just wastes money.

 

[ken75ranger]

So the consensus is that if it aint pinging, no point for higher octane. No other benefits?

There is a small benefit if you use a major brand like mobil. They have a better detergent in the higher octane fuels. You really wouldn't need it more than a couple tanks a year though. It's easy to just get a can of carb cleaner and dump it in the tank 2 times a year.

 

[DownhillManiac99]

There is a small benefit if you use a major brand like mobil. They have a better detergent in the higher octane fuels. You really wouldn't need it more than a couple tanks a year though. It's easy to just get a can of carb cleaner and dump it in the tank 2 times a year.

Thats why I run 91. Burns cleaner etc.

 

[Broncobowsher]

I don't believe people are still falling for the myths of "cleaner" high octane fuel. This ain't the 60's anymore.

As for running too much octane, yes it can be a problem. In extreme cases (you will never encounter) high octane burns so slow that it is still burning as the exhaust valve opens. Cooks that poor little valve. This is what happened when nascar truck series first started out with the 9:1 roller cam motors.

For the street, lower octane burns faster, giving higher peak cylinder pressure sooner. Providing it isn't too soon or too high (that would cause ping, knock, detonation, aka bad stuff) then you are actually making more power on lower octane then with high octane fuel.

Race gas is a different breed. It is both high octane and fast burning. But incostent between batches and expensive.

So run the lowest octane the engine will live on. get it from reputable stations so that it is clean. Never fill up when the tanker is dumping a load into the stations tanks.

 

[70_Steve]

For the street, lower octane burns faster, giving higher peak cylinder pressure sooner. Providing it isn't too soon or too high (that would cause ping, knock, detonation, aka bad stuff) then you are actually making more power on lower octane then with high octane fuel.

In addition to the "faster burning" thing, the lower octane fuel actually has a higher BTU content. This also means more power on lower octane.

 

[ken75ranger]

I don't believe people are still falling for the myths of "cleaner" high octane fuel. This ain't the 60's anymore.

Actually the only difference between brands of the same octane is the addivtive package such as detergents.
From the LA gov't.
From Refinery to Consumer
After crude oil is refined into gasoline and other petroleum products, the products must be distributed to consumers. The majority of gasoline is shipped first by pipeline to storage terminals near consuming areas, and then loaded into trucks for delivery to individual gas stations. Gasoline and other products are sent through shared pipelines in “batches”. Since these batches are not physically separated in the pipeline, some mixing or “commingling” of products occurs. This is why the quality of the gasoline and other products must be tested as they enter and leave the pipeline to make sure they meet appropriate specifications. Whenever the product fails to meet local, state, or federal product specifications, it must be removed and trucked back to a refinery for further processing.

After shipment through the pipeline, gasoline is typically held in bulk storage terminals that often service many companies. At these terminals the gasoline is loaded into tanker trucks destined for various retail gas stations. The tanks in these trucks , which can typically hold up to 10,000 gallons, usually have several compartments, enabling them to transport different grades of gasoline or petroleum products. The truck tank is where the special additive packages of gasoline retailers get blended into the gasoline to differentiate one brand from another. In some areas, ethanol may be “splash blended” in the tanker to meet environmental requirements. When the tanker truck reaches a gas station, the truck operator unloads each grade of gasoline into the appropriate underground tanks at the station.

 

[wildbill]

%) %) %) If you run a 9 to1 or less you only need 87 gas the higher is a wast of money. But in a few states you got watch they have 85 and it sucks. And a stock efi need's only 87 also on the carb. motors also. I run the green gas in the 289 and it's 5.00 a gal. and it gets about 4 mpg 12:5to1 motor but what a kick have fun. %) %) %) Bill

 

[ginwisconson]

I have a 302 and since buying my EB about 6 months ago, I have always put the best octane in my beast assuming that, even if negligable, I get some benefits of engine life, etc? Am I way off and I should just throw the regular unleaded in there? Would it make a difference that my truck is used to the good treatment if I went back to the lower octane? Thanks guys

Mark

If it don't ping, run the cheapest.