<VV> OCTANE CALCULATION

[Jim Burkhard]

Strictly speaking, with mixes as you describe, one needs to perform to 
same  onerous laboratory Motor and Research tests with a CFR engine to 
calculate the new octane. That's because 93 (or whatever) octane fuel 
from one station at a point in time is not necessarily the same 93 
octane fuel from a different sdtation at a different point in time and 
it doesn't necessarily respond to being mixed with another fuel in the 
same way.

That said, taking a straight arithmetic ratio (i.e. average them if you 
are mixing 50:50) is close enough for anything but true laboratory 
testing.  You might be +/- 1 point or so depending on the specific 
hydrocarbon compounds in each of the component fuels, but it's not a big 
deal for street driving.  Easy enough, huh?

Jim Burkhard

JR wrote:
> ----More and more stations are going to one hose per pump. Makes me feel like 
> I'm getting a hose full of 87 before any 93 makes it to my tank. The NEXT 
> guy gets lucky and gets a hose full of the 93 that "I" paid for!------