C 12 side note

[Shawn S.Kvaas]

The c12 fuel I ran in my car this weekend at mission was from last July when I bought it for Woodburn. I had half a tank sitting in the car since then, and 3 plastic 5 gallon jugs sitting under a tree in my back yard out in the elements. all this fuel tested perfectly every time.

[Ed Wright]

Originally Posted by Shawn S.Kvaas

The c12 fuel I ran in my car this weekend at mission was from last July when I bought it for Woodburn. I had half a tank sitting in the car since then, and 3 plastic 5 gallon jugs sitting under a tree in my back yard out in the elements. all this fuel tested perfectly every time.

I ran the first race this year on left-from-last-year C11. It had been in the plastic jugs in my trailer over the winter. Checked perfectly, "right in the middle" they told me. Never a problem with C11.

[Darrin Christen]

Originally Posted by Ed Wright

I ran the first race this year on left-from-last-year C11. It had been in the plastic jugs in my trailer over the winter. Checked perfectly, "right in the middle" they told me. Never a problem with C11.

Only problem with C-11 is the price! Lower octane, yet cost more than some of the higher octane fuels.

[Ed Wright]

Originally Posted by Darrin Christen

Only problem with C-11 is the price! Lower octane, yet cost more than some of the higher octane fuels.

Darren, in my car it's a tad faster on C11 after adding about 5% WOT air/fuel. More octane than you need costs a little power. Of course, in slow down mode that doesn't matter. :-)

[KRatcliff]

Isn't C-11 a little quicker burn rate than C-12? No?

Lower octane doesn't hurt as long as you are not detonating. A quicker burn rate is....well....quicker.

I can see how C12 would check ok in Mission. I think it has a harder time in the heat of our area if not properly stored. And sometimes it will be marginal right out of the drum.

This also may be due to their testing equipment at the tracks.

[Dave Ley]

C11 has a much lower specific gravity than C12. The lower the specific gravity the faster it burns. Faster burning means more power. You aren't paying for octane you are paying for the properties that make it have a lower specific gravity.

[Darrin Christen]

Thanks for the explanations guys.
Specific gravity
C-11 .710 @ 60* F
C-12 .717
C-14 .696
C-16 .735
C-25 .695
At No Problem Raceway for the D4 race C-11 and C-16 were $16.00 per gal. and C-14 was $14 per gallon. Sorry for getting off the original topic. I do run C-11 with no problems at fuel check as of yet, but I'm new to this super stock stuff. Maybe I should try some C-25, I could use all the help I can get.

[Crew Chief]

Originally Posted by KRatcliff

This also may be due to their testing equipment at the tracks.

How is it that most everyone passes and only a few fail? If the testing equipment was bad wouldn't everyone fail?

[KRatcliff]

Originally Posted by Crew Chief

How is it that most everyone passes and only a few fail? If the testing equipment was bad wouldn't everyone fail?

This is based on my experience at the fuel check in Div 4. I use C11 in my stocker and C12 when I drive our Calais super stocker. Without question C12 was the one that would come up bad from the others being checked. And many of the comments would be "I just got it off the truck.."

The testing equipment looks like something from the 80's. Maybe it isn't that critical, but I am not the first to question how up to date their equipment is.

[Jody Lang]

The real problem is the way the testing process is set up. To be clear the parameters or window that the fuel is suppose to test within.

When I've been close to failing fuel check it's always been on the low side. A few years back at Sonoma many of us were close to failing or failing.

I went and bought a fresh 5 out of a new drum. They tested it for me and said it was perfect, right in the middle. Why if when we fail it's always on the low side, but when the fuel is fresh it only starts out life in the middle?

Shouldn't it start out life at the top of the scale???