Fuel Grade ?

[Bob 007]

Just over 900 miles on my 2019 MT 07 & loving it . So far I have only run 91 octane gas , my question is can I switch to 87 without any loss in performance or damage to the engine ? 

[mossrider]

Just now, Bob 007 said:

Just over 900 miles on my 2019 MT 07 & loving it . So far I have only run 91 octane gas , my question is can I switch to 87 without any loss in performance or damage to the engine ? 

Yes, it is engineered to use 87 octane. You'll never tell the difference.

[Stephenms]

These bikes are tuned for 87 and up. If pinging occurs then change accordingly. I've been running 87 since mile 0 with no issues. I did switch to 93 for a few weeks to give it a try and felt no difference in performance or sound.

[topazsparrow]

Unless you diddle with the ignition timing (aka a tune) you won't notice any difference between 87 and 91+

Generally the premium gas runs cleaner so it might be "nicer" to your engine in the long run - but that remains to be proven really.

 

[sorkyah]

47 minutes ago, topazsparrow said:

Unless you diddle with the ignition timing (aka a tune) you won't notice any difference between 87 and 91+

Generally the premium gas runs cleaner so it might be "nicer" to your engine in the long run - but that remains to be proven really.

 

They just have more detergent additives usually

I run mine on 91+ because that's what it's tuned for

But before I flashed the ECU I was running 91 in the Summers and 87 in the winters

At over 110, the bike will start pinging on 87 w/stock tune

[Bob 007]

Thanks for the reply's . Sounds like if you want what is best for your engine you spring for the 91 octane .

[rider]

I've tried all the grades just to see.  Couldn't tell any difference at any speed or style (except the price), so I run 87 as recommended by Yamaha. 

I have a Yoshi R77 and my wife has a Two Bros S1R on hers, no flash (yet) or other performance mods on either.

BTW,  we both think the Two Bros sounds better and her bike seems a little faster with it.

 

[FZ07R WaNaB]

4 minutes ago, rider said:

no flash (yet) or other performance mods on either

Highly recommend getting the 2WDW flash and removing the snorkel - your bikes will run a LOT better especially with those pipes. You will have to run 93 octane though as that was what was told to me by 2WDW. I run Shell 93 V-Power, and I can tell the difference between that and 87 with the flash!

[rider]

Just now, FZ07R WaNaB said:

Highly recommend getting the 2WDW flash and removing the snorkel - your bikes will run a LOT better especially with those pipes. You will have to run 93 octane though as that was what was told to me by 2WDW. I run Shell 93 V-Power, and I can tell the difference between that and 87 with the flash!

Yeah.  Now convince my wife...

[timjh]

2WDW had one case of pinging with 87 after a flash, so they recommend higher just in case.  Honestly, at a few pennies per tankful why skimp?

That said, I ALWAYS use TopTier in all vehicles (except rentals), regardless of octane.  I don't think GM/Audi/BMW/Ford/Honda/Toyota/Etc. recommend it just for grins.  Most, but not all, major brands meet the TopTier spec.

[FZ07R WaNaB]

Just now, timjh said:

(except rentals)

I even did that once...

I ended renting (for a reasonable rate) a 2019 Camaro SS with the 455hp V8. It was on empty when I picked it up - stupidly, they gave me the option. They would have used 87, and I said hell no, and took it to the Shell station for the V-Power. That was my best rental EVER!

"Best" is defined as many holeshots, high speed runs and no loss of license

[wingbit]

I've been using 87 since new, no issues, runs strong.

[3crows]

Many areas have no ethanol fuel available but usually only in 87 octane. A few places no ethanol is available in higher octanes. There is no difference in the additive packages in most quality, name brand fuels. You can always add Techrolene. 

[Grant31781]

I started off with 93 when I got the bike last year. Now I run 87 in my 2018. No issues in this Georgia heat. I can not tell any difference in performance.

[Beemer]

19 hours ago, Bob 007 said:

Thanks for the reply's . Sounds like if you want what is best for your engine you spring for the 91 octane .

Save your money, the factory already did the testing for you and they say 87. If they thought it didn't clean well enough they would've told us to use 91 with more detergents and I haven't heard one complaint about 87 octane or other damaging someone's engine. People are just over thinking it and being overly critical. Here's a clip from this article: "It won't make your car perform better, go faster, get better mileage, or run cleaner."

Paying a Premium for High Octane Gasoline?

---

Higher octane fuel is not necessarily better for your car.

 

 

[NikitaUCLA]

23 hours ago, Bob 007 said:

Thanks for the reply's . Sounds like if you want what is best for your engine you spring for the 91 octane .

ah....I don't think so. The smart people use the cheapest which is 87 in the US (equivalent to 89 in Europe).

2017 FZ07, 10,000 miles/year , oil change once a year regardless of miles.

My 1987 Yamaha FZR1000 took me to 40,000 before even needing a valve adjustment. Yes, it was also on 87 octane.

Premium fuel is for suckers. 

If your owner's manual doesn't "requires" premium, why would you spend more?

[Zeus]

I've ran both 87/91, no difference on the stock tune.  I stick to 91.  I'm not sweating the $1 difference per tank.  If not grade I do swear by Shell as my station of choice

[shinyribs]

Unnecessarily high octane can actually hurt performance. It burns much slower than lower octane numbers and somewhat delays the combustion process. There's absolute no power gain at all with higher octanes. 

 

There's extra additives in higher octanes to produce the slower burn. If you're engine doesn't need them you are paying for something that you're literally blowing out your tailpipe. You're also introducing ingredients that your engine doesn't need/can't efficiently process and can cause undue carbon build up.

It's literally a waste of money and resources. These bikes run in tip top form on 87 octane and ethanol. It's what's they were engineered for. Basically, static compress ratios and valve timing ( can profile) determine what octane an engine needs, among other small details. If someone "tunes" your engine without changing any of the basics ( compression ratio and cam) and it suddenly requires extra octane to operate safely....I'd reconsider. $0.02

[kylerhsm]

On 7/6/2019 at 11:31 PM, shinyribs said:

Unnecessarily high octane can actually hurt performance. It burns much slower than lower octane numbers and somewhat delays the combustion process. There's absolute no power gain at all with higher octanes. 

Exactly, and thus why it also makes bikes harder to start.

[bugeyes]

A higher octane grade will cause a shorter more distict explosion and that way resist pinging better at high rpm. The downside is that it actually contains less energy affects gas mileage and have none or negative effect on lower rpm performance.  If it's not needed then dont use it.

[Zeus]

I'm no tech/engineer, can't the ECU adjust to the fuel grade?  I'm well aware that higher octane is of no benefit unless tuned, but I'd be surprised if it had adverse effects.

[norcal616]

52 minutes ago, Zeus said:

I'm no tech/engineer, can't the ECU adjust to the fuel grade?  I'm well aware that higher octane is of no benefit unless tuned, but I'd be surprised if it had adverse effects.

No, it's not self-adjusting...

[cyow5]

1 hour ago, Zeus said:

I'm no tech/engineer, can't the ECU adjust to the fuel grade?  I'm well aware that higher octane is of no benefit unless tuned, but I'd be surprised if it had adverse effects.

Contrary to what BugEyes said, higher octane burns slower. This is what allows you to run a harsher environment in the cylinder (higher compression, more boost, etc). Also because of the slower burn, you can advance spark timing a bit more, and this is what causes it to be a waste of money in an engine with later spark timing (for lower grade fuel).

An ECU with knock control does self-adjust for the fuel grade though. Rarely does it add timing unless it had previously pulled timing out and is just restoring it. You're playing with fire though since knock control is not as good as we'd hope. It can be very hard to distinguish between knock and mechanical noise from the valvetrain, so it can catch a lot of false positives if not done very well. 

 

[Zeus]

18 minutes ago, cyow5 said:

Contrary to what BugEyes said, higher octane burns slower. This is what allows you to run a harsher environment in the cylinder (higher compression, more boost, etc). Also because of the slower burn, you can advance spark timing a bit more, and this is what causes it to be a waste of money in an engine with later spark timing (for lower grade fuel).

An ECU with knock control does self-adjust for the fuel grade though. Rarely does it add timing unless it had previously pulled timing out and is just restoring it. You're playing with fire though since knock control is not as good as we'd hope. It can be very hard to distinguish between knock and mechanical noise from the valvetrain, so it can catch a lot of false positives if not done very well. 

 

That makes sense.  I was under the assumption that considering the varying demographics and emissions regulations the ECU would be more adept to adjusting to octane levels.  I guess I overestimated it  

[cyow5]

2 minutes ago, Zeus said:

That makes sense.  I was under the assumption that considering the varying demographics and emissions regulations the ECU would be more adept to adjusting to octane levels.  I guess I overestimated it  

Yeah, I worked with one engine that couldn't even detect any knock at all on half the cylinders, so you just had to assume they weren't knocking if the other half weren't. We knew when it was knocking or not by using pressure cylinders, and anyone who tunes knock control without them is going to have to leave something on the table. 

 

Some ECUs now (such as F1) use in-cylinder pressure transducers, and these have really been able to take full advantage of knock limits, but anyone using an acoustic knock sensor is really hamstrung.