Commandos and fuel octane rating

Rockithound said:
I have spouted off on this topic before: I run my Commandos on aviation fuel purchased at a small local airport: 100 octane LEADED gasoline. Not only do the bikes run like it's 1973 again, I still use the original fiberglass petrol tank on a 1970 Commando S. Last time I purchased (August '23) price was a little over $4 / gal. Other then the fact that the fuel is dyed blue in honor of "no road taxes collected" (but who's checking?) - zero issues.
Click to expand...
Little hard when the closest is 80 miles away, $5.40/gal, and they say don't come back without an airplane! Personally, if I were going to commit tax evasion, I certainly would not state it publicly!

AvGas sales are heavily regulated, as well as its use. Many fuel dealers for aircraft will only sell AvGas if they fuel the aircraft themselves. A legal grey area exists, as small gas stations next to private airstrips sell AvGas from standard fuel pumps. So once it’s in the tank, it’s not their problem.

Working with such a loophole is how some people get AvGas to use in other types of vehicles. Since AvGas does not have any duties or taxes on it, you cannot use it on public roads.
 
P.S. Some folks around here use aviation fuel for chain saws, leaf blowers, snow throwers, lawn mowers, etc. - i.e. equipment that doesn't thrive on ethanol laced pump gas... and it works great! There is no legal problem with purchasing & using aviation fuel this way & the local airports have no issue with selling fuel to customers pumping av-gas into gas cans, which is how it's done.
 
It's the same situation here, the Aviation fuel is 100 octane leaded, ethanol free and a bit pricey. For fun I might give it a try on Dyno hill.
As others have pointed out, when on a long ride we are still stuck with minimum e5 on fill up.

The nuisance is getting rid of that e5 or e10 when parking the bike again back at home.

Glen
 
Rockithound said:
P.S. Some folks around here use aviation fuel for chain saws, leaf blowers, snow throwers, lawn mowers, etc. - i.e. equipment that doesn't thrive on ethanol laced pump gas... and it works great! There is no legal problem with purchasing & using aviation fuel this way & the local airports have no issue with selling fuel to customers pumping av-gas into gas cans, which is how it's done.
Click to expand...
There is no legal issue as long as it's not used on the road.
 
Sta-Bil the fuel that sits around. Works fine in a generator, which is where my sit around fuel ends up. Starts every time I check on it. One pull starts. lol
 
Rockithound said:
P.S. Some folks around here use aviation fuel for chain saws, leaf blowers, snow throwers, lawn mowers, etc. - i.e. equipment that doesn't thrive on ethanol laced pump gas... and it works great! There is no legal problem with purchasing & using aviation fuel this way & the local airports have no issue with selling fuel to customers pumping av-gas into gas cans, which is how it's done.
Click to expand...
Correct.
It is COMPLETELY LEGAL to purchase and use aviation fuel for ground equipment.
 
concours said:
Correct.
It is COMPLETELY LEGAL to purchase and use aviation fuel for ground equipment.
Click to expand...
I love such categoric statements on an international forum.

You should maybe qualify it.......in the US state you live in!

In France? I doubt it. Do I know people using it in race bikes? Maybe. Am I one? Nope.
 
If you think it is legal in the US to use leaded gas on the roads: https://www.epa.gov/archive/epa/aboutepa/epa-takes-final-step-phaseout-leaded-gasoline.html

You can quibble that the law only prevents the sale for on-road use. You can also stick your head in the sand that you are not paying highway taxes when you use avgas and no one will care.

In at least parts of Europe where gasoline costs a small fortune due to taxes, I bet they take and even dimmer view of evading those taxes.

Avgas is ridiculously expensive due to the additives - not taxes in the US.

I'd like to see a video of you driving onto any local airport within 30 miles of me and filling your gas can. WAS or IAD.
 
Fuels
marshg246 said:
If you think it is legal in the US to use leaded gas on the roads: https://www.epa.gov/archive/epa/aboutepa/epa-takes-final-step-phaseout-leaded-gasoline.html

You can quibble that the law only prevents the sale for on-road use. You can also stick your head in the sand that you are not paying highway taxes when you use avgas and no one will care.

In at least parts of Europe where gasoline costs a small fortune due to taxes, I bet they take and even dimmer view of evading those taxes.

Avgas is ridiculously expensive due to the additives - not taxes in the US.

I'd like to see a video of you driving onto any local airport within 30 miles of me and filling your gas can. WAS or IAD.
Click to expand...
I have used unleaded premium gas in my motorcycles since the early 1970s. I found that Amoco unleaded premium caused far less carbon build up than Sunoco 260 and I never had problems with spark knock in engines with as high as 10.5:1 static CR. Todays R+M octane ratings are higher octane at a given octane rating than the old MOR system.
 
worntorn said:
SteveA said:
I love such categoric statements on an international forum.

You should maybe qualify it.......in the US state you live in!

In France? I doubt it. Do I know people using it in race bikes? Maybe. Am I one? Nope.
Click to expand...
Click to expand...
That, is why I agreed to have the flag displayed. It really is easy to understand.

Please re-read my post, take note of the quote in my post, to another member from the US.

They are not STATE laws, but rather, Federal. Applicable in all 50 States.

Ground equipment refers to any non-roadgoing equipment.


As to knowing the laws in YOUR country, correct, I do not know them.

But thank you for the advice on how to structure my posts. 👍🏻
 
Last edited:
Commandos and fuel octane rating
 
Using a higher octane that is necessary will only hurt performance. Higher octane only raises the flash temperature of the fuel. I once tried 110 octane race fuel in my 2006 Dodge charger. My 60 foot times went to crap!
 
I tried various fuels on Dyno hill.
My best result so far has been with 91 Octane E zero. Next was 94 Octane E zero. Yes lower Octane fuel has more power per unit than high Octane, the opposite of common perception.

All of the ethanol type fuels made the bike go a bit slower than the E zero gas, even after multiple jetting changes. I found that a 270 mj gave the best power on the e5 or e 10 whereas a 260 works best with E zero.
I've been hoping to try some lower octane E zero, 87 or 89 would be interesting, but have not found any yet and it's doubtful that I will.
I can still source the E zero 91 Octane although it now is labelled " May contain up to 10% ethanol".
I test every batch at home. What a pain!

Glen
 
Well all I know is my Norton runs better on 98 premium non E10 fuel and same with my Yammy 30hp two stroke outboard motor, my Thruxton well it runs great on any fuel I use but I will stick with the 98 as they seen to run a bit cleaner and I get more mileage to a tank full and as I always say each bike/owner is different and in Aus we don't get the best quality fuels here.

Ashley
 
worntorn said:
I tried various fuels on Dyno hill.
My best result so far has been with 91 Octane E zero. Next was 94 Octane E zero. Yes lower Octane fuel has more power per unit than high Octane, the opposite of common perception.

All of the ethanol type fuels made the bike go a bit slower than the E zero gas, even after multiple jetting changes. I found that a 270 mj gave the best power on the e5 or e 10 whereas a 260 works best with E zero.
I've been hoping to try some lower octane E zero, 87 or 89 would be interesting, but have not found any yet and it's doubtful that I will.
I can still source the E zero 91 Octane although it now is labelled " May contain up to 10% ethanol".
I test every batch at home. What a pain!

Glen
Click to expand...
Interesting and confirms what what others says. Though ethanol burns slower so ignition timing adjusted might change outcome.
My main reason to prefer non E fuel in road bikes is short best before date. Living in a country where half of the year is too cold for pleasant riding.
 
concours said:
As to knowing the laws in YOUR country, correct, I do not know them.

But thank you for the advice on how to structure my posts. 👍🏻
Click to expand...
I have lived here for 8 years, after 8 years in Italy.......as for knowing the laws in either.....well honestly....not that well!

UK laws? Probably know them less than I think I do too.

All 'advice' freely given, you are welcome :oops:
 
You must log in or register to reply here.
Back
Top