Octane

I have to run (the US crap) premium in the MINI only because it is supercharged and the head is shaved. My wife's 2.6L Mercedes calls for premium, but we run regular in the winter and mid-grade in the summer until it gets really hot and I notice a ping then switch to premium. If I drove it and subjected it to my style of driving, it would probably require premium all the time (lead foot).

The true name of the game is to run the lowest octane rating possible without subjecting the engine to pre-detonation (pingng). Alcohol is the root of all evil both mixed with gasoline and mixed with the economy. The object of course is to burn every bit of fuel possible by using a volatile fuel and increasing the timing to the point just prior to the engine pre-detonating. Alcohol reacts to temperature changes more than gasoline and it's hard to make a choice when temps vary like they have been doing here lately. I actually had to lean out my R3 due to the heat last week, I'm sure it had alot to do with the alcohol content of the garbage we have to use, Budman found some pure gas and I can't wait to try it out.

If you haven't used it before, try out the lowest octane you have available and see how that works for ya. I bet it might even be a noticeable improvement.

Ishmael, I generally run 98 because hardly any servos sell both 98 and 95. When I have run 95 it certainly hasn't made any noticable difference, so I'd happily run that if it was more readily available. Think I'll do what HellFire says and try good old 91 and see if I notice anything, at least while it's cold here. At 15c a litre cheaper it's probably worth a try, although I recall being told when I first got the bike to always run premium (95+) but I might be confusing that with my car. Anyway, will let you know what I find out.

The Triumph rep gave you good advice...run the lowest octane and if you notice any pinging...then move up one grade....any more than that you are just throwing unnecessary money in the gas tank and unused fuel out the tail pipe.

And I like the comment on the Harley filling up having to use premium...premium gas for a non premium bike...that's rich.

Dennis

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

I've learned several things from this thread so thanks guys.
Not the least of the learnings was about the two scales for octane rating. I never knew. Thanks Bill .

lucky me

I have been flying radial engines (R2000 and R2800) for several years they burn 100 low lead that green avgaz and since we always drain tanks before each flight I ended up with several 45 gals drums of the stuff which I use for the rocket smell different than pump gaz but make her go quite nicely (I think the compression ratio is also very similar) between R3 and R2000.
my supply is dwindling sad to say and soon i will have to go to the pump like everyone else!

Just a word of caution. 100LL (low lead) aviation fuel has 10 times the lead of the outlawed automotive leaded gasoline. In anything with a catalytic converter it is obviously not a good thing, but I think it would be tough on other internal engine parts which were designed for no lead. Just a concern.

Oh, missed this last time, but 100LL is what aviation Low Lead but does in fact have 10 times what car lead had. It is BLUE. RED fuel, hardly ever seen now days, is HIGH LEAD. Just a work of caution.

Jim/Maine said:

Oh, missed this last time, but 100LL is what aviation Low Lead but does in fact have 10 times what car lead had. It is BLUE. RED fuel, hardly ever seen now days, is HIGH LEAD. Just a work of caution.

Click to expand...

Jimmy the 100LL is green the 100-130 was blue, the 80 87 was if I remember pinkish I have not seen that one since 1990. and the jet A/ B are yellowish
I pumped thousands of gls of avgas into wings with radial engines in the last 40 years . you are right it has lead but it also has moisture inhibitors , antifungi and a few other nasty chemicals but to me the best was that it was FREE .and for harley engine the stuff was perfect when you consider that the Milwaukee engine is actually a radial with only two cylinders .

Free is good. I own an aviation company which pumps thousands of gallons of 100LL and works on piston aircraft (and Jets, and pump jet fuel which is really clean kerosene). Blue is the color of 100LL (easy to research on line), not sure what your fuel is. But no matter, just a lot of lead. Not sure what the ramifications are for R3 or other engine types, just that the designers/manufactures have made adjustments to the metallurgy from not having lead, and I am a bit concerned with adding it to my bike (even though I have lots available for pretty much free. It also has 100 octane which I do not know how that would work for our bikes. Thanks for the discussion, debate. Prefer friends call me Jim. Let's be friends. Raining here and cold, so taking a day off riding and with the limited summer it is painful. Got to move somewhere where I can ride more year round. Maybe that would be a good thread? Then again, at my age, riding years are numbered.

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.