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Which octane are you using?
- Thread starter mivaldes
- Start date
m in sc
Well-known member
87. low compression doesn't matter. i'll occasionally put premium in it but that's usually because i habitually grab that due to other vehicles.
There's no harm to premium other than the minimal impact to your wallet. On the plus fuel sold as a higher octane has a higher requirement for detergents it contains, which reduce carbon build up in the engine. Premium fuel brands also often have more detergents.
From the manual:
Higher octane does not make more power, it just resists detonation and controls combustion better for circumstances where the engine is optimized to make more power but would encounter detonation that would hinder that with lower octane fuel.
Something else to keep in mind is that most gas station hoses hold about 1/3 gallon of the fuel grade from the previous purchase, so whatever you select, you can expect the first 0.33 gal or so to be whatever the previous selection was. For most vehicles that's not significant, but it is for a 1.4 gallon motorcycle tank.
From the manual:
I run 87 octane (mid-grade where I'm at, high elevation) which exceeds Honda's recommendation, and if there are two gas stations at an intersection and one is a name brand, I'll go to the name brand and pay the tiny bit extra for their fuel. Our regular fuel at this elevation is 85 octane which the US Department of Energy has stated is only suitable for carbureted vehicles at high elevation and not modern ('80s+) fuel injected vehicles that target a specific air-fuel ratio.
Higher octane does not make more power, it just resists detonation and controls combustion better for circumstances where the engine is optimized to make more power but would encounter detonation that would hinder that with lower octane fuel.
Something else to keep in mind is that most gas station hoses hold about 1/3 gallon of the fuel grade from the previous purchase, so whatever you select, you can expect the first 0.33 gal or so to be whatever the previous selection was. For most vehicles that's not significant, but it is for a 1.4 gallon motorcycle tank.
fmdualexhaust
Active member
All my small engines and motorcycles get non-ethanol fuel.
My local station is 90 or 91 octane.
Luckily it is a dedicated pump so I don't have to wonder what was left in the hose.
My local station is 90 or 91 octane.
Luckily it is a dedicated pump so I don't have to wonder what was left in the hose.
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mivaldes
Member
- Joined
- Feb 12, 2022
- Messages
- 37
Very interesting about the residual fuel in the hose. Maybe I will fill my car up with premium next time and get a 5 gallon container after it has flowed for a minute for the CT125.
Yeah, but then I'd need to drink 87 ethanol free!
m in sc
Well-known member
stations here have 3 sperate hoses, or at least the ones i use. but yes, thats true if theres only 1 hose. it doesnt matter until you get over 12:1 to be honest.
Tman
Member
Well, like "fmdualexhaust", I try to use non-ethanol in my small engines and usually 90 or 91 octane and it's usually a separate pump where I buy it. One of the positives about higher octane is that it has a longer shelf life which I appreciate for my "back up" supply. I think we have the possibility of being in a better position than most if some of the projections for gas prices & availability come true. I read yesterday that one oil company executive was predicting that we could easily see $7 / gallon in the next year or two. If that happens, guess I'll be using the LRD for a greater part of my transportation needs.
m in sc
Well-known member
VP did a study , 87 octane pump gas has a shelf life of 2 years, vp racing fuel can go 8 and still be ok. If your fuels degrading there's either garbage in the tank, or water in the tanks at the station (likely, especially at a marina), or another issue. 14 bikes currently, most vintage, all carbureted but 2, and 2 vintage cars and i've never had fuel go bad where it wouldn't run, even sitting well over a year. If you store them outside in containers that seal like crap, then yeah, it will be an issue. that's my direct experience. And I run pump fuel in everything.
Fuel stabilizer is inexpensive, I use it anytime I expect I might not go through a tank of gas in a vehicle for 3+ months. With ethanol gas it will still draw in moisture which leads to rusty gas tanks, so best to keep the fuel tank topped off.
A study was just published with evidence supporting that the complete lifecycle emissions of cultivating land for, growing, and processing corn into ethanol as a gasoline additive outweighs the benefit of how much cleaner it burns. Now everyone who's ever had to deal with the destruction ethanol causes in fuel systems that weren't designed for it, along with everyone wronged by the lower fuel economy of ethanol diluted gasoline, can breathe out an "I told you so."
www.pnas.org
A study was just published with evidence supporting that the complete lifecycle emissions of cultivating land for, growing, and processing corn into ethanol as a gasoline additive outweighs the benefit of how much cleaner it burns. Now everyone who's ever had to deal with the destruction ethanol causes in fuel systems that weren't designed for it, along with everyone wronged by the lower fuel economy of ethanol diluted gasoline, can breathe out an "I told you so."
Environmental outcomes of the US Renewable Fuel Standard
Biofuels are included in many proposed strategies to reduce anthropogenic greenhouse gas emissions and limit the magnitude of global warming. The US Renewable Fuel Standard is the world’s largest existing biofuel program, yet despite its prominence, there has been limited empirical assessment of...
www.pnas.org
m in sc
Well-known member
I don't use stabilizers either, waste of money. basically snake oil imho. if you want to reduce any possible fuzziness use 1 oz tcw3 2 stroke oil in 2 gallons of fuel. helps keep it from evaporating as much in a not so airtight environment.
Plenty of studies supporting fuel stabilizers and hundreds of OEs (especially small engine and marine manufacturers) recommend their use. They usually contain fuel detergents, corrosion inhibitors, antioxidants, and water absorber (breaks up water to prevent corrosion and freezing). At ~$0.20 to treat a full tank in the CT125 with STA-BIL, depending on region it can be cheaper and more accessible than trying to fill with non-ethanol gasoline for storage. 2-stroke oil is another great idea, that will stay mixed in long term storage.
m in sc
Well-known member
yeah ducati did too... to stop the swelling of the acerbis tanks on the sport classics (they recommended star-tron) . didn't work and there was a lawsuit... and ducati lost. was nice to get a free 2800 tank from them over that on my old 09. (look it up) so no, i'll never believe stabilizers work in modern fuels. but they dont hurt anything either.
SneakyDingo
Well-known member
- Joined
- Aug 6, 2021
- Messages
- 1,573
Sounds on par for Ducati, they also made coolant reservoirs out of plastics that became brittle when exposed to alcohols, the very thing they were meant to contain
m in sc
Well-known member
point being that the advertised benefits of the star-tron additive, in-fact, didn't work.
Acerbis is a tier supplier for Ducati, it fell on them ultimately, but i'm not a proponent on ducati build quality, either. it's meh at best, and i've worked on my share of them.
Acerbis is a tier supplier for Ducati, it fell on them ultimately, but i'm not a proponent on ducati build quality, either. it's meh at best, and i've worked on my share of them.
When refueling your dirt bike, opt for ethanol-free unleaded gas with an octane rating between 87 and 92.
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Kev250R
Well-known member
I run 91 in mine but that's because I have yet to burn-through an entire tank of gas in less then three months. I've been averaging 50 miles a month so far this summer on my Trail (it's getting used primarily one or two weekends a month at a lake where I go camping). Recently I wondered if I could go the whole summer camping season on only one tank of gas!
I also use Sta-Bil for anything which is going to be parked for more then a month though so far the only Ethanol-related issues I've had have been fuel lines getting brittle and breaking.
Interestingly, I recently had the top-end rebuilt on my TRX450R Quad which is high-performance, race-type engine. It's very hot here and not the right time to be doing a break-in ride. I told the Mechanic who did the work it would be at least a month until I'd be riding the Quad he said not to worry about it; they'd filled the tank with AvGas which he said takes a very long time to go bad, if ever.
I also use Sta-Bil for anything which is going to be parked for more then a month though so far the only Ethanol-related issues I've had have been fuel lines getting brittle and breaking.
Interestingly, I recently had the top-end rebuilt on my TRX450R Quad which is high-performance, race-type engine. It's very hot here and not the right time to be doing a break-in ride. I told the Mechanic who did the work it would be at least a month until I'd be riding the Quad he said not to worry about it; they'd filled the tank with AvGas which he said takes a very long time to go bad, if ever.
Kev250R
Well-known member
I'll be honest, I never knew this until just now. I've seen 85 Octane for sale at the pump when I travel in Utah and always wondered about the why behind it. Though tempted to run it because it's cheaper, I never have since the truck I'm generally driving when I'm in Utah runs on 87 at home and everyplace else. Next time I'm up there with one of my Carb'd bikes or 'buggies I may give it a try.