I used to have a few service stations that sold pure gasoline 93 octane, now those stations only have pure gas with 90 octane. They all sell 93 octane with ethanol.

Why no more 93 pure gas I have not been able to determine.

So question is which better choice at this time? 90 octane pure gas or 93 octane with ethanol?

 

Use 93 with ethanol and add Marine Stabil for protection.

 

Interesting.....how frequently??

 

The only place I've seen 93 or better pure gas is at racetrack pumps

91 pure gas has been generally available around here for a few years

From what I can see 91 pure will run as well as 93 w/ 10% ethanol. The reason is that the energy content of the ethanol blend is lower so a larger volume of fuel will be needed, this causes the injectors to run closer to the ragged edge of their duty cycle where they are less efficient. This is for track use, in street use it's probably not much different.

I've been using Startron(preferred) or Stabile for longer term storage when an ethanol blend is in the car. The reason for using a stabilizer is that gas and ethanol will separate from each other over time w/ temperature fluctuations( spring and fall are the worst), The stabilizer alleviates the issue.

 

How much StaBil Marine to use to counteract the ethanol? I've been using 1oz/10 gal. Is that enough?

Also, I usually pour it in after fill up so it doesn't get "mixed" in till later. Is this an issue?

Thanks

 

Why wouldn't you put it in first so it gets mixed right away?

 

This may be of use: http://www.pure-gas.org/extensions/map.html

 

Thats what I do...Marine Stabil in first, then fuel to mix it thuroughly in the fuel tank.

 

How does stabil improve the gas?

 

I use whatever 93/92 pump gas that is available. Once a year I put two consecutive tank fulls with Techron added. Seems the issue with alcohol blended gas for a daily driver is overblown. Now for cars stored over winter or that sit for weeks at a time treating the fuel may always be a good idea.

 

you do this regularly, every tank? i had no idea this was commonly used in our cars

 

A question on octane rating from a guy called Ron . . .
You couldn't make it up . . .!

 

Stabil makes an ethanol treatment so you don't need the marine brand

http://shop.advanceautoparts.com/p/s...FYEYgQodZ9ULtA

 

Stabilizers like Stabil are critical to use in small gasoline engines, like lawnmowers. Ethanol gums up carbs and loves to help digest rubber.

HOW MUCH STA-BIL® ADDITIVE SHOULD I ADD TO FUEL?
For STA-BIL® Storage, use one ounce (30mL) to 2½ gallons (9.5L) of gasoline, gas/oil mixtures, or ethanol blends.

For STA-BIL 360° Performance, for storage and everyday ethanol treatment​ use one ounce (30mL) to 5 gallons (19 L) of gasoline, gas/oil mixtures, or ethanol blends.

For STA-BIL 360° Marine, for storage and everyday ethanol treatment​ use one ounce (30mL) to 10 gallons (38 L) of gasoline, gas/oil mixtures, or ethanol blends.

 

Yessir!

This is the correct way to use ANY fuel additive.