What octane do you run?

[Rambler358]

I know 87 is specified, but does anyone use 89 or 91 octane? Does the higher octane gain you anything?

[01ragtop]

I run Premium and name brand at that. It makes no difference in power or mileage. The reason I run Premium is purely an anecdotal observation. I have had no trouble with gummed up carbs or injectors on any of my three bikes while using Premium. Can't say the same for regular.  

[RobF]

I usually run pure (i.e. ethanol free) gas, which typically only comes in premium (92?) octane ratings. When I can't find ethanol-free gas, I just use regular. Most people (myself included for many many years) have a strong intuition that octane is a measurement of the fuel's energy content (analogous to calories in food or proof in liquor), but that isn't the case. The octane rating offers some indication of the fuel's resistance to detonation under compression. Some engines (typically high performance) with higher compression ratios or quirky cylinder heads have a tendency to "over-compress" the fuel and so are prone to pre-detonation (aka knocking) when the fuel-air mixture decides to just spontaneously detonate under compression rather than wait for the carefully timed ignition spark. If your engine can run low octane fuel without pre-detonation problems, then there is no performance gain associated with running a higher octane mix.

[fatshoutybloke]

I know the labels are different but standard unleaded in the UK is 95RON, that's what I use on the advice of the mechanic at the Honda dealer where I bought my 6th gen. The big companies also sell their performance fuels, BP Optimate 97RON, Shell V-Power 99RON, etc.

[Bent]

87 octane pure gasoline when possible which is most of the time.  Premium has run very poorly in all three of my VFR's.  Honda recommends 86 or above.  

[Alan553]

sometimes higher  octane in an engine that does not need it doesn't fully burn, compression and temps not high enough and  you can get a miss under WOT....most top tier gas has the same detergents package through their entire octane line up so clean is not a function of 87 or 93.

[Duc2V4]

When I did a series of runs with different octanes a few years ago on my 6 Gen (w/Power Commander V), I found that the better average MPG I got was from using 87 octane. To avoid any "clogging" issues, I'll usually run Techron or other cleaner through a couple of tanks of gas at least once a year. That and I try and stay away from the bargain basement gas stations! Sometimes in the more rural areas of the state, you have no choice, it's usually after these types of trips when I run a cleaner through.

[Dustin]

Here we have mandatory E10 in lower grades but some stations offer E0 in 91 octane. I have experimented with the 91 E0 in my '02 VFR but I found that it offered no appreciable benefits for the increased price.

My main takeaway was that while it did run a little more smoothly with the 91 E0, throttle response was muted as a result. The biggest problem was that cold starts were difficult. When the temperature dropped, the bike would take two attempts to fire before holding idle. With 87 octane, it'll start up straight away and idle perfectly even in subzero temperatures.

[thepretender]

Dyno tests show depending on engine between 1 a 5% drop in HP using 91 when 87 is recommended. 

 

[Duc2V4]

19 minutes ago, thepretender said:

Dyno tests show depending on engine between 1 a 5% drop in HP using 91 when 87 is recommended. 

 

Hey, I know you! Welcome to the fray!

[RobF]

15 minutes ago, Duc2V4 said:

Hey, I know you!

 

Are you sure it's him? Is it possible he's just pretending?

[Rectaltronics]

I do not have access to ethanol-free gasoline here.

 

I do have experience switching between the grades of gasoline available here and found profound and consistently repeatable differences in low-RPM performance (including knocking and greater tendency to stall at "lugging" RPMs) when switching between the least expensive and most expensive grades.  During my tests I tried three different major brands of gasoline (Mobil, Shell and BP) and the differences remained repeatable and predictable.  Actually I seem to recall a tank of low-grade Sunoco not fairing well either.

 

I did not evaluate any of the mid-grade gasoline formulations here.

 

Common wisdom is that the actual gasoline does not differ from brand to brand, only the additives.  I cannot confirm or deny this, but it supports the apparent consistency of gasoline performance (without doing an internal top-end inspection) from brand to brand.

 

It is entirely possible that the ethanol is a major contributor to this low-RPM performance loss with the lower grade gasolines but until I can spare the time to get out to a station with ethanol-free gas and try a gallon or two of each, this test will have to wait.

 

I would expect that people who spend little or no time in urban stop-and-go traffic and/or generally spend most of their time at higher RPMs would never notice the problems I have experienced with the lower grade gasolines.

 

I did not test mileage.

[Duc2V4]

3 hours ago, RobF said:

 

Are you sure it's him? Is it possible he's just pretending?

[BusyLittleShop]

Our knowledge about gasolines hasn't made much progress; because some
people are still buying more octane than they need...

 

A motorcycle manufacture's octane rating has to take into account the
vast elevation changes inthe USA... that means they must pick an
octane based on the fact that you may venture from the highs of
Colorado to lows of the Pacific Coast... your engine is more likely to
ping next to Pacific Coast than in the rarefied air of Colorado...
that means no matter what octane you choose... listen for pings... if
you hear pings go up one octane... no pings go down one octane... all
in all you may end up burning 87 octane even though the manufacture
recommends 91 octane... you just live at the correct altitude that
produces no pings...

 

Most engines sport 11.5 to 1 compression and will still burn 87 happily...
you may hear your combustion chamber ping once or twice each year...
that's not enough to go up one octane... especially if the ping happens on
the side of a steep hill in San Francisco while you're incinerating the clutch
to get moving from a stop light...

 

Owner manuals suggest octane ratings based on general terms and
conditions in order to generate the least amount of complaints...
but an engine will always speak specifically to your conditions and
with more authority... how???

 

The internal combustion engines speak in their own language as to
the correct octane... the ping or knock is their cry for the next
higher octane... no ping means engine satisfied... smart riders start
with the lowest octane and work up listening for the ping or
knocking...

 

Knocking is defined as an explosive combustion of part of the fuel/air
cylinder charge, after burning begins... What the ear hears are the
shock waves of the normal flame pattern colliding with the detonated
fuel/air mixture...

[01ragtop]

There is a lot of misinformation regarding brands and differences between regular, mid grade, and premium. Some of it is marketing, some information or misinformation comes from the companies themselves.

 

He's retired now, but my dad worked for a fuel distributor for several years, and I've had the opportunity to tour the plants where the stuff is produced. They only manufacture regular and premium. Mid grade is a mixture of the two. The mix varies by brand, but typically mid grade is 60/40 regular/premium. The additives are not consistent across all grades. Yes, I know what the marketing says; no, I don't believe it because I've seen tanks filled with the mixture and pumped directly into the trucks that deliver it to the gas stations. I've also seen the bulk plant run out of the mixture and instruct the truckers to mix regular and premium in the tanker trailer to create mid grade.

[Alan553]

5 hours ago, Rectaltronics said:

I do not have access to ethanol-free gasoline here.

 

I do have experience switching between the grades of gasoline available here and found profound and consistently repeatable differences in low-RPM performance (including knocking and greater tendency to stall at "lugging" RPMs) when switching between the least expensive and most expensive grades.  During my tests I tried three different major brands of gasoline (Mobil, Shell and BP) and the differences remained repeatable and predictable.  Actually I seem to recall a tank of low-grade Sunoco not fairing well either.

 

I did not evaluate any of the mid-grade gasoline formulations here.

 

Common wisdom is that the actual gasoline does not differ from brand to brand, only the additives.  I cannot confirm or deny this, but it supports the apparent consistency of gasoline performance (without doing an internal top-end inspection) from brand to brand.

 

It is entirely possible that the ethanol is a major contributor to this low-RPM performance loss with the lower grade gasolines but until I can spare the time to get out to a station with ethanol-free gas and try a gallon or two of each, this test will have to wait.

 

I would expect that people who spend little or no time in urban stop-and-go traffic and/or generally spend most of their time at higher RPMs would never notice the problems I have experienced with the lower grade gasolines.

 

I did not test mileage.

 

Its true ...here in the northeast...gas is gas...the only difference is the amount of detergent that gets added to the tanker before it leaves the refinery. Sticking with Top Tier products hopefully gets you a little more than what the Feds require.   Shell  seem to be the only one that advertises a different additive for their premium, i.e. Nitro??  Other than that...gas and oil...who owns anything long enough to find out what works and what doesn't.  But their isn't a motorcycle, truck or auto message board that does not beat the topics into the ground. That's part of the fun of how we stay connected, agree, disagree and banter....

[Bent]

Gas thread, oil thread, nearly the same thing.  If your bike runs good, leave the fuel alone.  If it runs bad, it probably isn't the fuel........

[01ragtop]

1 hour ago, Bent said:

Gas thread, oil thread, nearly the same thing.  If your bike runs good, leave the fuel alone.  If it runs bad, it probably isn't the fuel........

Hey, don't leave out tire threads. 

[Bent]

On September 10, 2016 at 10:51 AM, 01ragtop said:

Hey, don't leave out tire threads. 

 

I think tire threads are useful.  Depending on where one lives and how one rides, tires DO make a lot of difference.  It's the only thing between the rider and the road surface.    

[01ragtop]

Yep, my only point was that they are full of opinions like oil and gas threads. Fact is, even though I have a preference on all three, it doesn't make me right, just the same as someone else's opinion doesn't make them right (or wrong).  

 

The tires I use, the octane I choose, the oil I prefer, is all based on events and experiences I've had with trying things out for myself and seeing what works for me. 

 

I drive a Ford truck. Why? Because the Chevy and Dodge I had before were junk, and the Ford is running great after 8 years of ownership. I run Bridgestone because they work better than the Michelins they replaced. I use Mobile 1 because I find no value in the additional cost of Amsoil, and I've already stated why I use premium. That's all me though. You may have similar experience that proves the opposite to you. 

Not to be coy: YMMV. 

[MackerVFRR]

This is one of the best "What Fuel" threads I've ever seen. Everyone responding is educated on the topic and absolutely correct. Post this on 600rr.net and watch the yahoo's come out of the woodwork.

 

Personally I've never had any problem running what the world's largest/most successful motorcycle company (that conceived, designed, engineered and extensively tested)  my Honda motorcycle tell me to run.

 

Buy quality fuel and limit the Ethanol. Also don't forget that a lot of these models are "World Engineered" ie: designed to run and thrive in places/countries with lower quality/lower octane fuels. 

[Belfry]

My 2006 runs well on 87 octane regular.  I put in a tank of 91 octane Shell V-Power premium every so often since, in western Canada, it's one of the few ethanol-free fuels. I 'think' it might clean out the fuel system, but I have no objective evidence. I also fill the tank with V-Power (and the specified amount of Sta-bil) when I put the bike to sleep for the winter to reduce or eliminate ethanol-related storage issues.  When I'm travelling in the states in the summer I usually go for mid-grade: a.) because I've been a few places (Colorado, for example) where regular has an advertised octane of 85; and b.) because gas is so much cheaper south of the border (even with the crappy exchange rate).

Note: I was trying to remember which state it was that had the 85 octane regular and Googled 'octane ratings Oregon,' which turned up this Oregon state government document that says, among other things, using fuel with a higher octane rating than specified by the manufacturer is a waste of money. 

[Rectaltronics]

To further add to all this entertainment I should point out that there are different gasoline formulations for winter and summer in many parts of the country.

 

And even from one year to the next, those formulations may differ significantly and their respective performance, depending on the engine and environment, could differ accordingly.

 

My own canary in the coal mine for this issue is my 2000 Honda Accord EX-V6 which several years ago developed a hot-soak issue out of nowhere.  That model car is known for the issue but it's not like anything about the car changed from the years it was OK to the year it started this crap.

 

The quick story about hot soak is that on warmer days (i.e. around 50F) with winter blend gas, if I pulled over and stopped the engine after everything was fully up to temp and left it like that for fifteen minutes or so, the fuel would start to boil in the injector rails from the heat rising from the engine block and trapped under the hood.  Then if I wanted to start the engine it would misfire on all cylinders and throw tons of error codes because the pump didn't have enough pressure to overcome the boiling point and the injectors could not deal correctly  with the boiling gasoline.

 

Then last winter the problem disappeared almost completely, as mysteriously as it appeared.

 

All that being said, my 8th gen ran poorly at low RPMs when using the 87 grade regardless of season and formulation here.  That not only included the things I mentioned before like greater propensity to stall on launches with minimal throttle, clearly audible knocking and noticeably poor seat of the pants performance, but also a significant difference in the "lugging" RPM.

[Switchblade]

87 with no problems ..

[SHvar]

I have tried gas at several locations and all octane ratings in my 2014 VFR800, so far minus some gas from one station I get no difference that I can feel or hear. There was a news report in my area on gasoline octane ratings a few years ago, and what they actually tested in a lab for octane ratings. The rated octane on the pump is the minimum permitted to be sold under that rating. Every station they tested had higher octane results, some by 1-2, others by a difference of 3-4 octane higher than what the pump was rated at. I run 87 octane on my VFR800 now. My Acura has a higher minimum requirement (90), its the only vehicle I use higher octane gas in.