Octane

[albertaduke]

Maybe this helps. Maybe the fuel you use is for your services special purposes? I know that I know less than I know, that much I know for sure.

2.1 Color-Coding. There are two categories of aviation fuel in use today: aviation gasoline (commonly called AVGAS) and turbine or jet-fuel.
A. Aviation Gasoline (AVGAS). Aviation gasolines are used in reciprocating engine aircraft. There are currently two grades of aviation gasoline in use: 100 low lead and 100/130. Off-colored fuel may not meet specifications and should not be used for aviation purposes unless samples have been taken and are laboratory approved. The following various grades of aviation gasoline are dyed different colors to aid recognition.
(1) Blue - 100 low lead (100LL)
(2) Green - 100/130
B. Turbine Fuel/Jet Fuel. Aviation turbine fuels are used for powering turbo-fan, turbojet and turboprop engines. There are two types of turbine fuel in use: A kerosene base (Jet A, Jet A-50, JP-8, and Jet A-1), and a blend of gasoline and kerosene (Jet B and JP-4). Most commercial operators utilize Jet A or Jet A-50, and the military normally uses JP-4 and JP-8. The specifications for JP-8 are similar to Jet A except that JP-8 has required additives for anti-icing, corrosion inhibitor, and anti-static. All grades of turbine fuels are colorless or straw-colored.

must have sniffed too much of it during my years of flying I stand corrected from the specialist
.... young pilots remember not to sniff the stuff or you'll end up like me mixing colors

 

[Power-Tripp]

Back-to-back testing

R3T testing - stock exhaust with 1" hole drilled through baffles. As delivered with stock map - blue lines.
Notice the red and green lines in the graph below:
GREEN - Mapped for 87 PON fuel.
RED - drained the 87, and replaced with 93 PON fuel - NO MAPPING CHANGES.
Solid lines - HP
Dashed lines - TQ





Since there seems to be a LOT of confusion as to fuel differences around the western world, I have put this list together with the help of a lot of others.

RON= Research Octane Number (Chemical test) - European/UK/AUS/NZ pump octane number
MON= Motor Octane Number (heated research motor test)
PON= Pump Octane Number (AKI/anti-knock index - R+M/2) - US pump octane number


Europe/UK:
98 Octane____________95 Octane_______________Shell V-Power (typical analysis)
98.3 RON_____________95 RON__________________99.7 RON
86.9 MON____________85.5 MON________________87.9 MON
92.6 PON_____________90.25 PON_______________93.8 PON

AU/NZ:
Actual test data or info from suppliers is scarce to nonexistent, but this data comes from several suppliers. Premium RON 98 available in some areas - same data as above.
Premium___________Regular
95 RON____________91 RON
85 MON___________82 MON
90.5 PON__________86.5 PON

US:
Premium 93 ___________________________________________Premium 91
(actual results from 25 stations)___________________________(Actual test results)
98.5 RON_______________________________________________ _96.3 RON
87.9 MON_______________________________________________ _87.9 MON
93.2 PON_______________________________________________ _92.1 PON

Regular 87 (absolute minimum US standard)
91 RON
83 MON
87 PON


While this is not an absolute, and some locations may be higher or lower, I hope this helps clear up the BS.

We've found that Chevron 93 locally makes more power than other brands. I've seen over 5% difference in back-to-back testing. However, the freshest fuel from the major brands always makes best power. [Example: testing two weeks ago, Fresh Shell 93 made 2 hp over week old Chevron 93 in back-to-back tests.]

I hope this helps,

-Wayne

 

[Molinoman]

Great...now we learn that gas has a "half life"...Ha!

Seriously Wayne...thanks for those numbers...that ought to be a sticky as it is a very good reference.

Dennis

13 dtg KAF
15 dtg Dubai
16 dtg Home for good!

 

[Power-Tripp]

Just happy to clear up a few misconceptions.

We see this type of difference with many different bikes.
Slightly more octane can add a slight improvement to the mid-range and top end - especially in hot weather. But,low end output and response suffers slightly. Mapping ignition advance to compensate for more octane, can make premium pump fuels work better than standard pump fuels.

Race fuels (non-oxygenated) and 100LL actually drop output everywhere. The mapping becomes too rich, since these fuels are more dense, and have different viscosity than pump fuels. You MUST map for these fuels to get anything out of them.

In back-to-back testing of an SV650, 93 pump gas made better output than 100LL - even with fuel mapping specific to 100LL.

I hope this helps.

 

[Jim/Maine]

Then we need to throw Ethenol into the equation right. I put a shot of Star Tron in most fill ups. Thoughts on this practice?

 

[Jim/Maine]

must have sniffed too much of it during my years of flying I stand corrected from the specialist
.... young pilots remember not to sniff the stuff or you'll end up like me mixing colors

I get the sniffing too much of it. Me too. I am really bad a remembering names, where I parked my car and all that good stuff too. But I still remember how to ride and I'll bet you do that well too.

 

[HellFire]

I used to use a couple gallons of low lead av-gas in my 67 small block 289 on weekends racing. The lead content was still so high that it left deposits on the valves and of course ate spark plugs. Good stuff, but had to pull the heads every couple months just to clean up the mess.

 

[albertaduke]

I used to use a couple gallons of low lead av-gas in my 67 small block 289 on weekends racing. The lead content was still so high that it left deposits on the valves and of course ate spark plugs. Good stuff, but had to pull the heads every couple months just to clean up the mess.

so you must have been the guy that came at night in a pick up with a 45 gls drum standing in the truck bed and drained fuel from my wing tanks from the old DC-3 I was flying , I had a double engine failure because of it.
remind me to tell you the story of it some day.
( lots of outboard motors ran on that batch of fuel in northern quebec in 1976)

 

[HellFire]

so you must have been the guy that came at night in a pick up with a 45 gls drum standing in the truck bed and drained fuel from my wing tanks from the old DC-3 I was flying , I had a double engine failure because of it.
remind me to tell you the story of it some day.
( lots of outboard motors ran on that batch of fuel in northern quebec in 1976)

Not unless it was yellow/black with "Rose Hill Public School dist" on both sides. LOL
(hey, I was a poor kid in a small town back in the 80's)

Naw, pumped the av-gas at the local sod strip where I learned to fly for turning a wrench. Every weekend the owner told me it was against the law, and every weekend he sold it to me anyway.

 

[CanberraR3]

Filled up with regular unleaded (91 RON, no alcohol) day before yesterday. Bike is running great; certainly no worse and maybe even a bit better. Engine is a tad quieter too. Still had about 4 litres of 98 in the tank so will have a more definitive idea after next fill - but so far so good. Almost 15c a ltre cheaper too.

Ishmael, sounds like your son was spot on. Hmmm, wish I'd tried it before now.