Fuel octane requirements

[cheaphooker]

Hey guys- the owners manual states that you only need to run 87 octane but everyone I talk to says put 91 or higher in it. I hae done both and can't really tell much difference. It is stock with the exception of V&H BR pipes. Will running 87 cause damage? I can't imagine it would do any harm id BDM puts it in the owners manual.....Idunno???
The scoot is an 06 mastiff

 

[Oscar Maldonado]

HMMMMM!

Mine says:

Use premium quality unleaded gasoline of 91. And it's an 04'.

 

[BigDognSoCal]

2007 manual..."87 octane min"...Did not know that...I have only used 91

This is fron the 2005 manual:

FUEL SYSTEM: Use only unleaded gasoline. Ethanol
blended gasoline is approved as long as it has 87 octane
minimum. Methanol or methanol blended fuel is NOT approved
for use in your Big Dog Motorcycle.

 

[Oscar Maldonado]

That's interesting seeing that I got the same info. from the 04' manual also.

 

[reloaderbmg]

in fla all gas has 10% ethanol!

in winter 87 oct is ok! but when it gets hot [in fla need 93oct
in june an a ride to daytona slow, larry & myself top up with 100 oct, [bikes ran like glass]

 

[cheaphooker]

All the fuel in the Dallas area is 10% ethanol as well and it is humid as shit here too...but no alligators. I figure why spend an extra 60 cents a gallon for 93 octane on an almost daily driver if it is not going to hurt it, improve performance drastically or make me look gay in any way
I have been running 87 for 2 months straight now and not a sputter, spit or hesitation. Go figure, maybe I'm lucky....so far

 

[BBChopper]

I run 93 all the time same in the Goat! :2thumbs:

 

[Fibersnake]

I run the higher octane, not so much because I need it, but more to be on the safe side and with the variables in the regular, no telling how accurate the 87 is. Throw in the more and more common addition of 10% ethonal and questions arise. Figure that even with the extra cost, but the use mainly for pleasure, at bare minimal the mid grade, normal the higher grade.

Will say that the few times it has had regular, it ran fine with no indication of pings.

Unless you have a lot of mods that bring the compression ratio up more, regular should do fine, even if border anything more than high test is not needed for most.

 

[reloaderbmg]

did a test on a car last week to check gas in tank! [for rough idle]
found 16% ethanol in fuel. & thats why your gas milage is going down!!:angry: :bang:

 

[scubaman15]

did a test on a car last week to check gas in tank! [for rough idle]
found 16% ethanol in fuel. & thats why your gas milage is going down!!:angry: :bang:

Could be the same in Richmond ???

 

[jwoolf]

The funniest thing is that I can run whatever I want to in the dog but, my harley requires 93 or better. LOL

The weisco 9.6:1 pistons when paired with the Andrews TW37G cam seem to compress the fuel so fast that I knock and ping with 91 in it but, the dog has never knocked and pinged with anything I've put in it.

I've been putting premium in the dog anyway just as insurance against it.