93 Octain Gas

[Snakebit]

With all the fuel efficient cars, there are very few people buying 93 octain fuel. I live in Salem, NJ a small rural town with a Sunoco station in town. I am willing to bet that I am among a hand full of people buying premium fuel. If this gas is sitting in the storage tanks, for who knows how long, will it go stale? Should I be adding stabil at every fill up?

[dcdoug]

A fair amount of higher performance modern cars require at least 91 octane (all our cars do). Many stations only have 87, 89, 93, so people use 93. I would doubt the gas sits in there long enough to get stale. Ask the station manager how often they have to refill that tank.

[Gunner]

Originally Posted by dcdoug

A fair amount of higher performance modern cars require at least 91 octane (all our cars do).

Ditto. And my prior driver, a 2000 Odyssey, would run on either 89 or 91 but would make ~5 more HP and get ~5% better mileage on 91.

[cdnus]

My understanding is they only keep the low & high octane in their tanks, everything in between is a blend of the two.
So that should prevent any fuel in their tanks from becoming stale.

I sure if that is incorrect someone will let me know.

Craig

[*13*]

I remember hearing that unless you are using the 92/93 octane within a few weeks that it actually declines in octane. If your fuel is sitting in the tank any longer than this you may consider running the medium grade fuel. I'm not a chemist, this came from a meeting held by one of the local oil/fuel companies.
With the economy the way it has been, most people I know have stepped down a grade in their daily drivers. I would guess this is pretty common across the board.

[dcdoug]

Originally Posted by *13*

With the economy the way it has been, most people I know have stepped down a grade in their daily drivers. I would guess this is pretty common across the board.

Great way to do damage to a $5k-$10k+ engine to save $.15 a gallon.

[Gunner]

Originally Posted by dcdoug

Great way to do damage to a $5k-$10k+ engine to save $.15 a gallon.

Yep. Some engines (like my Honda) use knock sensors and adjust. Most higher-performance engines (like both my Volvos, and several others in the past few years) REQUIRE 91 or higher for sustained operation without damage.

If I only had $0.15 for every old fart who told me I was wasting money putting premium in these cars, I'd have a free tank of juice.

[WardL]

The octane of gasoline does not drop unless it is exposed to sunlight for several days or more. If your fuel is stored in a air tight container not exposed to a lot of light you are ok for at least a year. Most retail sites do blend premium and regular to make their midgrade. The State Weights and Measures people go around and measure the octane of gasoline. Call them up and ask how many low octane samples they find. It should be less than 10%. The low ones are usually due to a little regular gas getting into the premium.

[Ron61]

The highest octane we can get up here at a station is 91 with supposedly 10% Ethanol added to lower the mileage. I can go to the distributor and get 93 octane with no Ethanol which I use in all of my lawn and garden equipment and mix a can in with the pump gas every so often. My little Comet runs much better when I do mix in a can of the 93.

Ron

[*13*]

There are a few stations around here with 100+ octane but the price is high. Usually 91 for the Cobra.

[Ron61]

Darn, the only 100+ octane we can get here is racing gas. How come you can buy it at the pumps down there where there is a lot of smog, or at least a lot compared to what little we have around here. Most of our Summer haze and smog is caused by forest fires.

Ron

[*13*]

If I could figure out California Politics I guess I'd be the smartest guy around.