Question About Gas

[Kachow]

I’ll try to make this my last question… At least for today. What kind of gas are y’all running in your rockets, the premium stuff 92 octane? I’m kind of hoping you’re gonna say 87 with the price being what it is these days. My Harley knock off needs premium but I don’t have an owners manual yet for my rocket so I can’t look it up.

 

[Vector]

Non-Ethanol 91

 

[Greyfell]

If you can't find non-ethanol fuel, find some Lucas Oil Ethanol treatment to add to the tank. 1 ounce treats 5 gallons.

Use this site to find ethanol free gas near you: Ethanol-free gas finder

 

[Kachow]

We have ethanol free but it’s all 92 octane. Does the OEM say specifically 91 or higher octane?

 

[Greyfell]

We have ethanol free but it’s all 92 octane. Does the OEM say specifically 91 or higher octane?

I don't believe it does, because the fuel injection should adjust to to the octane level. If you want to use lower level octane, I really recommend the Ethanol treatment. I usually get my supply at O'Reilly Auto.

 

[Vector]

" Does the OEM say specifically 91 or higher octane?"

AFFIRMATIVE

https://triumphtechnicalinformation.com/handbooks/6256128485731a676a6fc6f1

 

[Greyfell]

" Does the OEM say specifically 91 or higher octane?"

AFFIRMATIVE

I stand corrected!

 

[Kachow]

It seems odd that it does specify the higher octane, because we had this debate on other bike forums and the guys who say they are experts were explaining that unless you have a high compression motor like 10 to 1 compression or your motor is knocking, you shouldn’t use the higher octane because it advances the spark, yada yada yada. Their bottom line was the oil companies are just trying to trick you into spending more money and it’s not even good for your engine, but I guess if mother Triumph says you have to do it, you should.

 

[Greyfell]

May I suggest a small research project? Go to one or two service stations, and compare the ethanol numbers for the various octane grades. I don't know for sure, but I suspect higher octane is suggested to overcome ethanol levels.

 

[Kachow]

I found this online, it’s page 79 (I think the rocket three manual), but it talks generally about the octane level for triumph motorcycles, and in this paragraph under fuel grade, it lists 87 octane:

Fuel Grade
Triumph motorcycles are designed to use unleaded fuel and will give optimum performance if the correct grade of fuel is used. Always use unleaded fuel with a minimum octane rating of 95 RON.Triumph motorcycles are designed to run on unleaded gasoline with a CLC or AKI octane rating (R+M)/2 of 87 or higher. Federal regulations require that pumps delivering unleaded gasoline are marked 'UNLEADED' and that the Cost of Living Council (CLC) or AntiKnock Index (AKI) octane rating is also displayed. These ratings are an average of the Research Octane Number (RON) and the Motor Octane Number (MON).EthanolIn Europe, Triumph motorcycles ar

 

[Kachow]

All right, I’m going to correct myself now. The page I posted is saying it needs to be a 95 RON octane which translates to 91 octane in the states. 87 is the anti-knock rating AKI. Nobody wants ethanol in their gas but you can treat ethanol gas, as someone wrote in this thread, but triumph says you have to have the higher octane to prevent knocking I guess. that’s a drag because at the moment the higher octane fuel I’ve been buying for my Harley knock off is over five bucks a gallon.

 

[brooke]

Tiger 800 required 89 , new 900 s require 87 . I just assumed that the newer engines would be set up for lower octanes ?
Just found it on the Google machine . Page 79 , Rocket manual , all triumphs require 87 octane . So it should be 87 , E fuel or not . You’re correct again .

 

[Vector]

All right, I’m going to correct myself now. The page I posted is saying it needs to be a 95 RON octane which translates to 91 octane in the states. 87 is the anti-knock rating AKI. Nobody wants ethanol in their gas but you can treat ethanol gas, as someone wrote in this thread, but triumph says you have to have the higher octane to prevent knocking I guess. that’s a drag because at the moment the higher octane fuel I’ve been buying for my Harley knock off is over five bucks a gallon.

Did you see the link to the wonder manual above?

 

[brooke]

No , I just googled the Rocket manual . What’s the wonder manual ?

 

[Vector]

Wonder is a typo

https://triumphtechnicalinformation.com/handbooks/6256128485731a676a6fc6f1

 

[Vector]

Tiger 800 required 89 , new 900 s require 87 . I just assumed that the newer engines would be set up for lower octanes ?
Just found it on the Google machine . Page 79 , Rocket manual , all triumphs require 87 octane . So it should be 87 , E fuel or not . You’re correct again .

87 or HIGHER is what the book says. I found it knocked a bit with 87. Runs really well on 91 or 91 octane free.

 

[Wire-Wheels]

Where I live we only have a choice between 87 and 91. My old carbureted 790 twin runs fine on the recommended 87. If I use 91, she pops and crackles a lot more than usual on deceleration. Not sure why. Works for me. ...J.D.

 

[Leroys73]

Where I live we only have a choice between 87 and 91. My old carbureted 790 twin runs fine on the recommended 87. If I use 91, she pops and crackles a lot more than usual on deceleration. Not sure why. Works for me. ...J.D.

It is because the 91 is designed to burn later. If engine is designed for 87 the spark comes too early for the 91. The pops and crackles is the unburned fuel exiting the exhaust valve then igniting in the exhaust. Higher octane ignites later thus left over fuel unless the computer adjust for it by advancing the timing.

 

[brooke]

Change is hard and understanding octane ratings is just one of those things . If mine was pre-igniting on its factory recommended fuel I would be changing fuel supplier and quizzing my dealer as to why it’s pinging on the specified octane .

 

[brooke]

Forgot to mention something about ethanol . It also serves as an octane booster , So deleting it will reduce the octane rating despite the fact that ethanol has about 30% less energy than petrol . Makes sense when you realize that 87 gas is more volatile than 89 or 91 .