Math challenge: Octane word problem

[2fast4mom]

Johnny's fuel tank holds 30 gallons. How many gallons of 110 octane race fuel should he mix with how many gallons of 91 octane pump fuel to achieve a blend consisting of 94 octane?

Anybody got a formula for this?

Thanks!

[Kavalk]

Here it is.
Move to Canada.
Buy 94 at the pumps.

Sorry. It's late. I'm tired. Had to do it.

[O/B Dude]

91 x 5 gallons, plus 110 x 1 gallon divided by 6 total gallons = 94.1 octane. (5:1 ratio)

So........

5 gallons of 91 and 1 gallon of 110 = 6 gallons of 94.1 octane.

25 gallons 91 and 5 gallons of 110, make 30 gallons of 94.1.

OK, why not use 87 octane mixed with 100LL av-gas? Much cheaper than race fuel and 91 premium. 1:1 ratio makes 93.5 octane. .9:1.1 ratio makes 94.1 octane. (.9 gal 87 to 1.1 gal 100LL)

Hope this helps. :D

[Superdave]

I don't think it works that way. If you take 90 octane and mix it with 100 octane at 1:1 you don't get 95 octane. :eek: I think Techno or one of the other "gasperts" (is that a word?) can give you more technical stuff than you could want. Let's wait on their reply.
DAve
;)

[Superdave]

http://forums.screamandfly.com/forums/showthread.php?s=&threadid=35347&highlight=octane+formula
More math than you think!!:eek:

[Jay Smith]

With the compression YOU are running ( 150-160 cranking )a 3 to 4 gal. splash of 110 will be plenty of octane in a 20 gal tank ! This ain't ROCKET SCIENCE just run the same everytime after you get your mixture set as the more race gas you mix the richer the motor will become as the race gas is lighter in specific gravity and will travel thru the metering system more quickly ( more freely ) and more fuel = richer mixture..............

Make it easy on yourself and make the mix so that it is an even number of race gas to an even number of super, as 1 race to 4 super to equal 5 gals you would not want a weird mixture as 1.2 gal. of race gas to 4 gals of super. Also remember that big citys have MUCH more MTBE in thier gas for emissions and this is an oxyegenator and cause heat and the probillity of more detonation , more rural areas has less MTBE so mix accordingly. the 1 and 4 mix will be fine for you.......

As I said IT AIN"T ROCKET SCIENCE just COMMON SENSE......

Too many people spend too much time trying to reinvent the wheel ! Lifes too short ! Just ain't that complicated unless people choose for it to become that way if so they got more time on thier hands than I do if they got that much leisure time come over to JSRE I'll put em to work always need the floors swept ! LOL.........!

Good luck ,
Glad your motor is running GREAT ! ;)

[steve]

Mixing the ratio is exactly as he stated. 1gal 90 + 1 gal 100 would = 95 octane. Its a simple proportion formula.

[O/B Dude]

Yes, what Steve said. As long as both fuels are rated at R+M/2 and both are no-lead or low lead, then add them together and divide by the total gallons. If you mix leaded fuel with non-leaded or low lead, you will actually get slightly higher octane than the numbers indicate due to the multiple knock inhibitors used in suck a mixture and the way they interact with each other. (That is per an Amoco Oil Co. rep that I talked to about this many years ago.) I would stick with the numbers and don't count on additional octane if you do use lead in the mix. My 2 cents. :cool:

[Techno]

What about them there octane boosters?
There was a good post on the STV site with something called tc-6 or close to that. A cheap little bottle does 30 gallons. Much easier than gallons of C stoff to B stoff.