Octane Rating

[Beamie]

What is the required gasoline octane rating in U.S. standard connotation?
Sticker on the bike notes RQ 92 minimum, but I don't know if the RQ is an Asian, European or U.S. standard.

[mlstephens]

Good question. I've done a bit of research into this, and can't come up with an answer as to how the value is calculated. I'd bet that RQ 92 is not a (R+M)/2 number, but a RON or MON number since the manual is printed in Taiwan and not specifically intended for the US, which means it would translate to US Octane of approx 87 or 88. The US method of calculating octane ratings is an average, and results in 4-5 points lower than the rest of the world numbers (i.e. 91 in EU is roughly equal to 87 US)

[Beamie]

Maybe the compression ratio and ignition timing of the engine would give a clue, but I can't find that either.

[mlstephens]

Compression ratio is 9.2:1, timing is 13 degrees at 1700 rpm, according ot PGO's website. Again, I'm pretty confident that octane of 87 (R+M)/2 is fine.

[paige]

I always put premium gas in all of my scooters. (Japanese, Italian, Taiwanese) The difference is but pennies per fillup, and I feel it treats them better in the long run. It only gets expensive when I fill up the car and, out of habit, put in the good gas.

[mlstephens]

I always put premium gas in all of my scooters. (Japanese, Italian, Taiwanese) The difference is but pennies per fillup, and I feel it treats them better in the long run. It only gets expensive when I fill up the car and, out of habit, put in the good gas.

If the ignition timing is set up for lower octane, which it appears to be, then there is absolutely no benefit to using higher octane fuel, unless the particular brand of fuel that you are using has additives (i.e. Techron) that the lower octane doesn't, and then it will keep the valves cleaner, but there will unlikely be any noticeable performance difference. The key is to purchase high-quality fuel, such as Chevron, Mobil, Shell, etc.

[Beamie]

I always put premium gas in all of my scooters. (Japanese, Italian, Taiwanese) The difference is but pennies per fillup, and I feel it treats them better in the long run. It only gets expensive when I fill up the car and, out of habit, put in the good gas.

If the ignition timing is set up for lower octane, which it appears to be, then there is absolutely no benefit to using higher octane fuel, unless the particular brand of fuel that you are using has additives (i.e. Techron) that the lower octane doesn't, and then it will keep the valves cleaner, but there will unlikely be any noticeable performance difference. The key is to purchase high-quality fuel, such as Chevron, Mobil, Shell, etc.

I agree. Higher octance fuel runs hotter, so if the engine isn't designed to require it, it is actually not as good, especially for an air cooled engine in the heat of the summer.

My air cooled Triumph required 97 octane fuel when it was manufactured in 1976. It won't run on less but if I go overboard and not mix the racing fuel down enough there is a noticible increase in engine heat as well as idling difficulties in the summer heat.

[Apiarist]

this is great info, thanks!

[DennisD]

I always put premium gas in all of my scooters. (Japanese, Italian, Taiwanese) The difference is but pennies per fillup, and I feel it treats them better in the long run. It only gets expensive when I fill up the car and, out of habit, put in the good gas.

If the ignition timing is set up for lower octane, which it appears to be, then there is absolutely no benefit to using higher octane fuel, unless the particular brand of fuel that you are using has additives (i.e. Techron) that the lower octane doesn't, and then it will keep the valves cleaner, but there will unlikely be any noticeable performance difference. The key is to purchase high-quality fuel, such as Chevron, Mobil, Shell, etc.

I agree. Higher octance fuel runs hotter, so if the engine isn't designed to require it, it is actually not as good, especially for an air cooled engine in the heat of the summer.

My air cooled Triumph required 97 octane fuel when it was manufactured in 1976. It won't run on less but if I go overboard and not mix the racing fuel down enough there is a noticible increase in engine heat as well as idling difficulties in the summer heat.

My 2006 air cooled Triumph requires 89 octane. Progress! It also doesn't leak oil all over the place as the one I owned in the 60s did.

You're not doing your stock scoot any good by going beyond the manufacturer's recommendation for fuel. You could be shortening its life or at least creating maintenance problems in the long run.

Dennis

[jrsjr]

What is the required gasoline octane rating in U.S. standard connotation?
Sticker on the bike notes RQ 92 minimum, but I don't know if the RQ is an Asian, European or U.S. standard.

That "R" is the R in the equation (R+M)/2 that you see on gas pumps in the USA. What the equation means is that the USA octane rating is the average of the two different octane ratings, ROM and MON. The ROM number is usually higher, which is why you see the 92 ROM octane speced for the Buddy. That's roughly equivalent to the 87-89 we buy as regular gas, so don't worry about running regular.

Remember, octane is not a measure of the quality of the gas. It's a measure of the resistance of the gas to detonation. Running too high octane fuel just retards your ignition, which is not good for the motor, so don't do it. That's really all there is to it and that's why.

[StL_Stadtroller]

My 2006 air cooled Triumph requires 89 octane. Progress! It also doesn't leak oil all over the place as the one I owned in the 60s did.

My '08 Enfield requires, like, 70 octane or something I think.