Read more about gasoline and other moto essentials on RevZilla's Common Tread: rvz.la/3lpDheI

I could listen to this guy talk technical anything about motorcycles all day. Very effective communicator!!!

I only use 93 octane in my Harley LiveWire. It seems to keep the plugs from fouling.

One of the other factors that motorcyclists have to live with is the fact that our gas tanks are relatively small. No matter what we purchase on the higher end, there will be a substantial amount of (most likely) lower grade fuel between the fuel nozzle and the gas station fuel pump. You won't be filling up with the fuel grade that you really want. When riding in a group, let your buddies fuel up first, as a courtesy. 😉

That protein shake comparison is probably one of the best I have ever seen when it comes to describing how octane works. Also, since bikes tend to get such good mileage, I tend to just run premium all the time anyway. At only 2-3 gallons a tank for me it's maybe $1-2 difference at most, so not that big of a deal to worry about for the potential benefits.

Fun fact, in CANADA, Shell V Power and other premium grade fuels at SOME other stations contains NO ETHANOL. Lack of ethanol is a good thing and I for one prefer gasoline with no ethanol, especially prior to parking the bike for the winter.

High octane gas also has anti-oxidents added, another benefit in addition to detergents. I'm a control engineer who's blended millions of barrels of gas and diesel for 31 years for Shell, Fina, Exxon-Mobil, Chevron-Texaco & PetroCanada. To my knowledge, we've never blended cheap, off-spec gas for the Quickie-Mart type of retailer. Every 50,000 barrel blend is on-spec, or reblended till it meets spec (Road Octane = (Motor Octane + Research Octane) / 2). Here in Canada, you can see a tanker from a big name refiner, filling the tanks of the "Super Save" gas station. The small retailers don't have their own refinery to make shit gas. They purchase on-spec gas from the big boys.

99 octane here in UK but very expensive. Good in winter because it degrades much slower than the higher ethonol fuels.

I believe the first 1.25 gallons from a traditional fuel station pump is whatever was last pumped through it if its a 1 fuel line model. If its a 3 or 4 line model pump than it will pump the exact octane selected from the start.

I've had to explain this to so many people who put premium in their corolla.

i use hand sanitizer on my gsxr

Here in the UK, there is another advantage to using the higher octane - it has 0-5% ethanol, compared to 5-10% in the lower grade. I always use it in my bikes, a 1978 Triumph T140V and a 1980 Suzuki GS550L. The Triumph was originally designed to run on high octane (98 on our rating system), so definitely benefits from this, and the Suzuki is probably better off with the lower ethanol. For the amount of fuel I use, it's worth the small extra cost.

I run 93 in all my vehicles (2016 mustang gt, 2022 Honda cbr300r) because even thou it doesn't increase power on the cbr (it does increase power on the mustang gt) it does clean the cylinder better and helps keep the engine running good

Now this is some High Octane content.... literally!

Started running exclusively Shell through my 2005 corroborated Harley after finding out they put more detergents than most other Top Tier stations. After a month of riding 75-100 miles a day and only using Shell my Harley was running noticeable better. Was able to do my first cold start in 10,000 miles without pulling out the choke.

Here in the Rocky's, he also have 85 octane because the air is thinner and different atmospheric pressure at higher elevations and it will burn like 87 just fine, only costs a little less. My California in-laws were freaking out that gas stations didn't offer 87 and they thought their Toyota sienna was going to die if they used it lol.

I've come to learn the owners manual is very different than many other's and is not your typical crinkle it up and throw away instruction pamphlet...it is a Fukn life saver! Almost like a "How to for Dummies". Broken down instructions and detailed pictures... perfect for a guy like me. 🤘

I have a friend who ran 87 octane in his 2014 Street Glide for years. It knocked and pinged all the time but he insisted that was okay. It was, until he cracked a piston and ruined his motor! 😮

As mentioned below, you should also talk about ethanol content in gasoline. All if not most gasoline today is sold with ethanol in it. Then there’s Shell’s V-Power 91-octane gasoline with 0% ethanol. A mechanic recommended I fill my FZ-07 with Shell V-Power for winter storage. The FZ-07 normally uses 87 octane.

It is about time someone (anyone!) mentioned that higher octane gas has more detergent!

An important thing to note is that modern engines have Knock sensors which detect if there is predetonation in the engine. It’ll pull back timing to stop the predetonation to save the engine, but you’ll make substantially less power. Running enough octane insures that the engine won’t be pulling timing so you’ll make more power, even if it can “technically” run on 87 safely. Also, higher octane gasoline can be useful if the outside air is hot and if you plan on driving up long hills. Both of those situations cause the fuel to predetonate so a higher octane will be safer for the engine. Lean fuel mixtures with hot air and high altitude are likely to knock, and high engine loads cause knock too. Driving uphill at a higher rpm is beneficial to prevent knock especially on turbocharged vehicles. Lugging the engine at 2000 rpm, flooring it, to try to make it up a hill can be dangerous. Modern performance cars can usually run 87 these days safely if you dont get on the throttle to hard and too long, but all it takes is one sudden predetonation event to chunk a hole in your piston so run the highest octane you can if it’s recommended, especially if you drive hard. Also, ethanol in gasoline isn’t as bad as everyone thinks. If you drive often to prevent water absorption and you have a modern vehicle with modern fuel lines there’s nothing to be afraid of. Ethanol increases octane for cheaper, and it also has a higher cooling capacity so it prevents knock further by lowering cylinder temps substantially. I’ve seen cars run e85 for over 100,000 km with no issues to the stock fuel systems, no oil dilution by ethanol, and no material degradation. Ethanol is only really an issue on old vehicles and some specific new ones, so research it yourself, but “Ethanol bad” isn’t really true at all. Also a side note, knock sensors do absolutely nothing to detect rod knock, like many people think. I’ve seen literally dozens of people think their engine is gonna blow because they have a knock sensor code.

Thanks for summing it up, Ari. As a non-native speaker having the privilege of running in a brand new bike, I watched the whole video a couple of times to make sure I understood every point. Much appreciated.

In the state of Minnesota, the regular gas and mid grade gas has ethanol in it. The only gas that has is ethanol free is the high octane stuff. I ride a 2018 GoldWing (which I know you love, and so do I) which calls for regular 87 octane and I will run it on trips if I'm going through gas quickly but won't put the regular ethanol crap in if I'm storing the bike. Thanks for the video!

i knew all of this aready, but you did a very good video. it was clear, concise, and understandable. im glad that you pointed out the differences of the European rating system versus the American one. a lot of people dont know this. however. i used to have an RX-7 with a Wankel and it would get around 2 mpg better fuel mileage with 93 versus 87. sometimes as high as 3 mpg. so it was worth the extra price. the car was more responsive because the plugs stayed cleaner and the fuel burned better because of the higher spark. again, thank you for making such a well done video. very professional.

i inherited my grandfathers 2001 holden ute (ls1 powered) about a year ago. he owned it since new, mostly hwy driven and he never gave it a hard time while he used 91 (our lowest). i couldnt get the black smoke to stop when i put my foot down, so i used 98 (premium) for a few tanks. After two weeks the car ran smoother and got better fuel economy on both 91 and 98. i still run 91 but every 5th fill up ill use premium, i dont know how it works but its been worth it

2:33 "Swole Sauce", Jacked Juice, Lift Liquid, Bench Brew, Maxing Mixture

Excellent video. Octane ratings is one of the first things you get thought about at schools like UTI/MMI, but most people have no idea what it does and are often mislead into buying the wrong fuel by the “standard/mid/premium” stickers that all the pumps use. The gas stations are counting on people not knowing the difference in an effort to up income.

You go to the pump and it has 1 hose with 3 selections you select 91 you can get up to a gallon of what the previous person purchased which is usually 87 and you end up paying 91 octane price for 87 fuel.

It's amazing how many people refuse to believe the truth about octane ratings. Thanks for attempting to dispell these myths.

There is one caveat to the octane thing. Some stations in certain states and provinces (I am currently in Canada) the do not have ethanol in their premium fuel. In those cases I always suggest running premium just to avoid the ethanol. I am in the fuel business myself, and we offer a no ethanol, super long life fuel. Anyhow, avoid ethanol at all costs in a motorcycle, especially if your bike will be sitting for more than a couple of months.

I personally run ethanol free fuel. Think it’s usually 90 or 91. Keeps my TE 610 rippin around the mountains here in the McKenzie valley.🤙🏼

I run regular 87 in my yamaha. But in October I start running 90 octane because at my gas station the 90 is ethanol free so there is no ethanol in my tank over the winter.

Explains it so well. Had a friend who had a car tuned for 93 and was running 87 randomly. Told him he's asking for trouble. Even showed him when computer was hooked up. Fast forward two days later. BMW Flys by and he floors it. Loud ticking sound began. Bent rod lol.

Also note that 91 (low est octain fuels) can use other additives which cause waxing. Great for efi injectors as it improves lubrication properties in the fuel system. However for a bike that sits alot and carby bikes it blocks up jets, being a right pain. Highly advise running 95 or 98 fuels in those bikes before storage or to drain the fuel from the fuel system. Only run 95 and up in my cars and bikes. Note, for Australia.

Good video. Here in Australia I run my Indian Springfield on 98. In the USA 93 but Canada I found I needed to regularly use an Octane booster as the heavily loaded bike would ping especially when climbing. The octane boost was effective. I have not experienced this problem in Australia. I avoid ethanol but you don't always know what your fuel is so I prefer major brands. Cheers and thanks. Fuel is cheap. Pistons are not.

Air Cooled Harley 1200. Was told to run 91 by the Dealer. Sometimes I run a Fuel Cleaner in the tank. Seafoam or Lucas

I only use 91 non-ethanol in everything but my daily drivers. I have a pickup truck I only drive every few weeks, my street bike, and all my power equipment. I still use a bit of Sta-Bil for winter storage, but it's nice knowing the alcohol will not attack the aluminum in everything.

Just going to add my data point here: I rode 400 miles from Kansas City to Illinois on a yamaha R3. I refueled 4 times, each time with different gas, and made a note of the average fuel economy in each segment in between gas stations. In my experience, 87 octane gas produced significantly lower fuel mileage - both lower overall mpg and lower cruising speeds to maintain a good instantaneous mpg. 89 was decent on both front. 91 was better than the previous two, but 93 was by far the best and provided both great overall mpg and high cruising speeds while maintaining good instantaneous mpg.

I had a BMW 1150 gs that called for premium fuel and would still knock or ping at high altitudes with it. I was in Canada and got a tank of Husky 100 octane fuel and noticed a substantial gain in power, it would literally pick the front wheel up coming off the line where the 91 in the states would not. Also had the same experience with an RZ350 two stroke when running 100 octane cam 2 fuel. Now being a auto technician for 35 plus years new cars have what is called a detonation sensor the listens for detonation and reduces the ignition timing to correct it which decreases performance and fuel mileage. I run premium fuel in everything for one to keep it clean inside which like he said cuts down on carbon build up which will contribute to detonation. Also with adjustable ignition timing you can run it more advanced which improves performance. So at very least run what is recommended.

I have a friend who has been delivering fuel for three decades. Most of the fuel that goes to the cheap discount locations is the same fuel that goes to the higher end ones.

I have done tests on 3 motor bikes 2018 xt 250, 2007 650 klr, 2015 650klr. Non moded and increased all 3 by one liter less per 100km. Less ethanol in premium means less corrosion and less rubber cracking, stiff diaphragms ect.

oof, when he used a pic of my bike and called me out for putting 93 in it, it hurt a little lol

I used to have a Honda motorcycle that was designed for 87. I would occasionally run 91 for the extra additives, but it definitely ran and sounded better on 87. Have also had to fill my air-cooled v-twin with 87, no big deal. Just stay off the throttle and be gentle.

I'm a daily rider and I run top tier 91 just for the higher detergent and and especially so in the summer here in Northern California where ambient temps are well over 100F. It can run on 87 but the bike gets around 50 mpg, average fill up is 3-4 gallons so 90 cents to $1.20 more a fill up is worth it to me.

Nice... I have a Toyota Corolla from 2006... been using only premium in it, and it’s 2021... took it a few months ago for inspection... the garage person said the engine is just as good as it was in 2006 :D

Depending on your compression ratio depends on what octane rating you can run. Ping aka knock can damage your piston. The bikes that run 87 can run 93 but there is no improvement on power or mpg. Higher octane gas does clean off carbon from valves and piston

Another point not mentioned. I hauled fuel for a living. Just because the station brand is on the pump. Doesn't mean that brand name is in the ground. The refineries set the price at midnight. These prices go out to the haulers. They dispatch drivers to go the cheapest refineries. All refineries have a no brand fuel as well. Shells no brand for example is MOTILLA.

In Layman's terms; use whatever grade/octane fuel the vehicle was engineered for. Eliminating Ethanol from fuel would be a far better improvement than using a higher octane gas or any gas additive.

You failed to mention that most high-performance motorcycle engines have knock sensors that will prevent damage from detonation by retarding the spark as necessary. If the detonation is caused by low-octane fuel, then using a higher octane may allow the engine to operate at full power. Also, detonation is not correlated with high rpm, but rather with high cylinder pressure, which produces high torque. On aircraft engines with controllable pitch propellers, suspected detonation is controlled by a selecting a richer mixture and a higher rpm setting.

My pushrod evo motorcycle engines would sound like glass was breaking in the cylinders when I used low grade fuel especially when I wanted to go faster. This problem resolved itself once I started using premium 93 octane gas. I felt smoother throttle response and a happier engine.

Great Advice! Matches my old Jeep book to a T. It advised that if knocking occurs on 87, switch to a 89 and so on if operating in warm, high elevation, dry environment- like Vegas. It worked perfectly on 89. Too bad the rest of the vehicle was junk.

My manual says 87 or higher…. And I will definitely say my bike seems to run smoother with 91-93, although that could just be my imagination too 😅 honestly as long as there aren’t any negative side effects of using the higher octane, the detergent benefits for giving some love to my engine internals are more than worth it. These bikes already get 80-150 miles per gallon. And my other ride is a Colorado that gets 20mpg…. So Personally the extra $0.50-$1.00/gal is more than worth it in my bike that I definitely ride harder. 🤷‍♂️

I can attest that this is true. Especially the detergents. I rebuilt a 1975 CB550F that was in bad shape. Gummed 4 barrell carb that sat for years all tarred up. After a full rebuild of carb and almost everything else, i ran high octane and it did keep that carb spotless for years. Same for my rebuilt 2002 Shadow. It wont hurt to run it and with a carb it may be worth it but true, no better horsepower. Plus, i think most modern fuel injected systems are designed for anti knock and ping with lower grade fuel anyways so you probably wont see any change. Just cleaner system. Which, if you keep cars for 10yrs or more, may be worth it.

Has anyone else ever wondered how much 87 you get out of the pump and lines when you click 93? There are separate tanks underground, how much volume of 87 do you buy before the tanks 93 reaches the pump? Half your motorcycle tank could be regular 87 before you actually get 93 out of the nozzle.

Meanwhile in a TW200.... *No more fuel* *Has moonshine* "That'll work"

I don't have a motorcycle but I do drive a 370Z, with a high compression engine. Because of Nissan's adaptive ignition timing, I can run lower octane gas than what the engine was optimally designed for, 98 RON. In the US market, Nissan specs a 91 AKI gas as a minimum octane and it does run acceptably well. I now use a blend of Sunoco SS100 race gas and Shell V-Power Nitro 91 oct to get a blended average 93.25 oct, which the engine really likes.

Fun fact....it takes 1.5 gallons of diesel to produce 1 gallon of ethanol. This is from the tractors it takes to prepare the land, plant the corn, harvest the corn and process the corn....

Ari is the best! Definitely a good acquisition by Revzilla! They needed someone to compete with Bryan Van. Please keep the technical articles coming! I loved these from Ari back in the day when he was with the other KZfaq channel. Let’s see him work on some stuff and do mechanic walk throughs/installs as well!

In most modern engines, the risk of engine damage from running lower octane than recommended is low. This is because there are almost always ping sensors, and the computer will quickly adjust by pulling timing (if there is variable valve tech available) or lowering the amount of fuel delivered (if there is electronic fuel injection). There is some damage risk, as there has to be some pinging to be detected, but the general effect is reduced power, and possibly worse fuel economy. Aftermarket computer upgrades can bring the risk of damage back by being much more aggressive with the variables that are held back when pinging is detected.

Bizarrely, my 2020 BMW absolutely HATES the higher octane stuff. I thought there was something wrong with it when I bought it, because it took a few attempts to start it when cold, until the dealer told me to put regular petrol in it. Runs like a dream and costs less too.

Well it's allowing more timing without detonation which in turn will result in more power when tuned for it, if say you are running vehicle originally designed to run 87, you get it tuned on 93 for max gains.

Would love to have this include non-ethanol octanes as well.

Interestingly enough, when I tried running 93 octane in my Suzuki Boulevard C90T years ago, I did it for the cleaning properties and not to increase power. What was surprising is that the higher octane made the engine run like crap. It didn't start running good again until I filled up with 87 octane. So, instead of using higher octane, I started using Sea Foam. It ran better than ever once I started using Sea Foam. I now have a new Gold Wing, and it also runs great on 87 octane with Sea Foam every now and then to help keep things clean and running smoothly.

The high octane in my area contains no ethanol while the low and medium contain up to 15% so as I approach the end of riding season, I only use high octane and stabilizer so that I don’t get the phase separation from the ethanol that leaves water in my tank during the storage months, even more so with my snowmobile which has a much longer off season. So there is more to to high octane than anti-knocking on high compression engines but thanks for the great explanation regarding power.

“Let’s open up the shop manual “ YESS!

So in general, it is good to use higher octane fuel on any type of engine even those that doesn't require it coz it cleans my engine better but trade off is I pay more for gas if my engine doesn't require it. On the flip side, it is bad to use lower octane fuel that what the engine requires.

I'm convinced that I ruined my Kawi 250cc by putting regular in it when it called for premium. I was being cheap and stupid and thought "Gas is gas, it'll be fine". A few years of that and it started sounding like quarters rolling around in a tumble dryer. I lost power from the engine on the way home and it refused to go over 15mph. I took it into the mechanics, but they never found out what was wrong with it (I didn't tell them that I used 87 so they didn't think to check inside the cylinders). Moral of the story: Don't 👏 cheap 👏 on 👏 the 👏 gas!!! I've got a Zx-6R now and I'm treating her right. 🏍

I once filled a full tank of premium into a suzuki boulevard designed to run on regular. The bike didn't want to ride, engine shut down on high revs. Had to empty the tank and fill up again with regular. Worked fine after that.. Learned a lesson for the years to go..

There have been car tests that show a slight mileage boost from 91/93. The detergent is critical. My 2010 E550 RWD 386hp V8 @ 158k drives like it has 425hp.

A good thing to note is that higher octane fuels also tend to almost “go off” faster. Meaning a lower grade fuel will keep its quality longer. This is more a problem in australia where I live as we get up to 98 which will go bad much quicker than US fuels as it’s much higher but yeah, do keep this in mind

I run BP Ultimate 98 octane for my R1. Bike loves it !

I have a 1984 yamaha xv750, and I use premium because it would reduce cleaning service time on my carbs.

Great video, best explanation of the science I’ve seen, thank you. I bought a new Kawasaki Versys 1000 in August 2020. Great motor, but I did notice some vibration at around 4000 rpm. Not unbearable, but that does correspond to 60mph in sixth gear so cruising around the legal speed limit became a bit tiresome. Some professional bike reviewers have also noticed this, but they mostly put it down to their new test bikes’ motors needing « run in » (as we say in the UK). So I did some more trips, but even after 1500 miles the problem was still there. Kawasaki recommend « E5 » unleaded petrol (gas), which as I understand it contains 5% ethanol. Both BP standard unleaded (95 octane in the UK) and BP Ultimate unleaded (98 octane) are E5, so they both meet Kawasaki’s recommendation. According to your science, and I know that this is accepted wisdom, I should have noticed no difference on switching from BP standard unleaded to more expensive Ultimate. And yet.... my motor is definitely smoother, and the vibration at 4000 rpm has virtually disappeared! I guess you will tell me that this is a placebo effect, just like homeopathy. I should get someone else to fill the tank without telling me which fuel has been chosen, and then see what I think. Maybe I will, but I don’t want to spoil the illusion!

Funny how so many dudes is UK and EU think their gas is better because "bigger numbers" 🤣 Always have to explain to them that no, your gas isn't any higher octane, it's a different rating system.

Nice talk. Here in Australia we have 91, 95 and 98 as standards. I did notice an extra 50kms of mileage difference per tank, between 91 and 98 though.

Quick answer: any gas that gets compressed heats up. This is the reason why turbocharged cars have an intercooler, its to cool down the compressed air. It is then mixed with fuel and compressed again in the engine. In high compression engines and turbo engines, this air/fuel mixture can get so hot during the compression that it can self ignite before the spark plug sparks, while the piston is still compressing the mixture, creating engine knock. This 1- damages your engine, and 2- steals some power from you as it pushes against the engine's rotation Octane helps prevent the mixture from self igniting by raising the temperature it needs to ignite

I use Shell V Power more for the additives & less for the actual Octane number. Keeps my engine surprisingly clean!

I put in what my owners manual recommends. 91 octane or better. 2017 Road King.

Many ppl come to the garage saying their cars are good because they always use 93 octane, I try to explain but they say” oh but my father said/my friend….” I didn’t know that 10/8 years ago after hear about I start to check out and I forget what my thoughts were! Nice video!

In EU we use premium gas in old carburated bikes and even lawnmovers not because of octane or power, but simply to avoid ethanol. For every cent you pay more at the gas station you spare an euro for ulrasound carbs cleaning.

Good discussion. Modern engine management systems make a big difference. My '92 K100 will run on pretty much any grade of fuel, even old gas. However, my carburetor Triumphs demand premium. Triumph specified 97 RON minimum for my '72 Trident. Even then, they will knock if I'm stupid enough to accelerate from too low an RPM. Lucky for me that non-ethanol gasoline is easy to find around here.

My protein drinks are now referred to as "SWOLE SAUCE" from here on out. lol. Awesome as always, Ari.

You are absolutely right. In addition you engine ECU will sense the difference in fuel by the O2 sensor and compensate. Therefore no power gains unless the engine is designed for high octane. Cheers

My hayabusa and zx6r love 87. With the stock tune having conservative ignition timing values I don't have any issues. Both bikes are raced and ridden hard on 87. On the other hand, my bmw k1200lt will knock even with 93 in it if you lug on it in top gear. All bikes are different, depends on how heavy it is and how you ride. But basically any bike can run on 87 if you are careful and know what knock sounds like.

I only fill her up with high octane fuel because in holland they add 10% bio ethanol to regular octane 95 fuel. Also, my fz1 has some crappy fueling between 4k and 5k rpm. With quality fuel this is much less noticable.

Thanks Ari, I learnt something today.... so thank you! I had a question, I have a classic motorcycle a 500cc Single cylinder Royal Enfield..... Could you make a video about carburettors? How to keep it healthy.... when to know its time to replace one, if damaged..... or more importantly how can one damage a carb unknowingly? Or just any tips for people who own classic motorcycles.

I have 2 older bikes..both Honda 250s..ones an 86, the other is a 91..I notice both run cleaner on high grade..I've experienced back fire with low grade..didnt notice more horsepower..just a cleaner smoother feeling ride

*This Guy...* He *EARNED* his *Subscribe!* Good stuff! Great introduction of base knowledge to build a better understanding of fuels and how they work. Now maybe folk will understand that tier1 and tier2 gas has nothing to do with octane rating because octane rating is called, grade; not tier. One tip: when putting away your bike or lawn equipment for the season and don't want to use fogging oil and stabilizers, at bare minimum, stall your bike by shutting off the fuel instead of using the kill switch or key. This will run the fuel out of the lines, bowls (if it's a carb), fuel rails, etc. and limit sludging and the corrosive effects of ethanol. Then, TOP OFF your tank to the filler neck with fuel before putting it away. The chemicals used to adjust the octane rating can evaporate quickly. By reducing the air in the gas tank, you reduce the effects of evaporation, hence, prevent octane rating loss. Simple practice of good habit goes a long way in protecting our tools and toys!

This guy is an absolute unit of motorcycle knowledge, not just some bro-science.

As a rule of thumb during the summer hottest months I use 93. Nothing like getting caught in traffic on an air cooled machine(83GS1100GL) hearing that ping noise when the temps get up there. I had an 07 FZ6 that if you ran anything but 93 in the summer would ping slightly under low rpm load. Anything with over 10:1 I would use 93 even if it calls for less.

I live in Missouri where 10% ethanol is mandatory with regular/unleaded gasoline. Since motorcycles sit here for a few months during the winter I avoid ethanol at all costs because the crap breaks down, eats up rubber, and actually pulls moisture out of the air and you end up with a gel-like substance in your carbs if left untreated with Stabil. I stick with the premium non-ethanol at 91 octane because it's a small tank and worth the potential reaming filling up a cage would cost. I've had no problems after storing the bike during winter without adding anything. I ride an old '79 XS Eleven Special that was designed for regular gasoline but it runs fine on the mix if I have to fill up somewhere where non-ethanol isn't available. Newer bikes not sure.

I run premium in my work truck. Every truck I’ve ever owned, and I’ve run them hard and for a long time. Never had issues with the engines. I’ve got a 2007 Silverado with the 4.8 vortec that’s only ever had premium. She’s about to roll over 325k. Still runs like new. I’ll take the hit to the pocket book for the good stuff, it seems to work good in all vehicles.

Thanks Ari! Been looking forward to a new shop manual!

Brilliant info regarding the Euro / US octane differences. Always wondered why UK has 99 octane and US seems to only offer 93.

To echo a few others, high octane fuels are often free of ethanol and stay fresh longer. If your bike sits all winter premium fuels will stay fresh. And no, fuel stabilizers don't work. Project Farm demonstrated this in a video showing that they did very little to prevent gumming and corrosion and did not keep the fuel fresh enough to ignite easily after 6 months. Premium fuel (non ethanol) did stay fresh. In summer, when I burn through fuel quickly, I run 87 octane. Near late autumn I switch to 93 octane and make sure I run a tank through so over winter the fuel in the tank and system stays fresh.

More people need to see this video, tired of listening to people at the track with stock engine's running race gas....

Loved this guy in "DJango Unchained"..... :-P

There's also the dark and magical 4th choice of gas. It's the second hose at the pump. It's the best for your engine and milage

Good article. Here's some trivia for you: the amount of energy in one gallon of gasoline is enough to lift the Empire State Building three feet! More trivia: modern motorcycles run more compression ratios than the muscle cars did 55 years ago with leaded gas. Now, most gas stations have one hose for the E10 blends. If your bike takes 91 octane and you put it 91, the 87 in the hose from the last guy will drag the octane down below 90. Better to spend the extra money on 93 to negate the 87. Many stations are selling 88 octane E15 gas. E15 is to be avoided because motorcycle engines are not designed for it. Around Pittsburgh the E15 and E85 are dispensed by their own separate hoses. Once you get west of the Mississippi River you may encounter stations that only have the lower octane gas. I've seen 86 octane "economy" gas out west. If it's the only option just listen to your engine and row the gears to avoid detonation. The old saying "buy the best you can afford" works on gasoline. Most motorcycle tanks are 5 gallons or less and for the extra quarters you spend you'll get a better product.

Here in Slovakia we have the standard fuel, which is marked as 95 and premium which is 100. What sucks is that the 95 contains up to 10% ethanol, which is no bueno for older engines, as the ethanol really harms fuel lines (especially during winter hibernation). That's more or less the only reason I put premium in my tank, I really don't wan't to damage my bike (2004 Suzuki SV1000S) with some garbage EU forces us to put in our tank. edit: premium fuel usually contains little to no ethanol