killing the octane myth (next death is brands)

[JAS6377]

There should be almost no difference in a regular GS. The only reason to up the octane is to prevent pre-ignition due to a higher compression ratio within the combustion chamber, or a modification to timing. This is why certain motors require higher octane, and will knock with low grade fuel (built motors, turbos, etc.).

Since the GS was designed to run on 87 (low grade), you won't see any benefits to running a higher octane, unless you advance the timing quite a bit, or do some SERIOUS engine work to up the compression ratio.

What's there to argue? Use the fuel that the vehicle was designed for. That's why they pay the engineers the big bucks.

[slipperymongoose]

Yeah they pay them big bucks for f%$k all.

[JAS6377]

I didn't say "Suzuki engineers"... Lol.

[slipperymongoose]

Keep that list going

[JAS6377]

Yeah, engineers suck. I am one lol. My main point was that if a vehicle is designed with a lower compression ratio/lower power motor, it will run properly on lower octane fuel, meaning there's no need for higher octane, as it will offer no benefits.

[slipperymongoose]

But the fuel companies say....................... And there engineers........................ And I notice a difference.......................... Octane matters..............

[adidasguy]

One member told me a friend of his told him that knows motorcycles told him that his engine was knocking and pinging from pre-ignition so he should get higher octane to prevent that because a hot engine does pre-ignition that causes pinging and stuff and all that and so forth.....

My opinion on that is while high octane can help, first one should see why the engine is running hot which is probably due to a too lean a mixture.

Octane will only mask the real problem of running hot.

Out bikes are designed for 87 so no reason for higher. If higher makes a difference, something needs fixing. The carbs on his bike probably need cleaning. Slightly clogged, dirty jets will make it run lean. (and change pilot from 37 to 40)

[slipperymongoose]

Cleans the engine out runs cooler

[Janx101]

I still reckon Old Bert from "worlds fastest Indian" was onto something.... he dropped half a nitrous oxide heart tablet into the tank before that run didnt he?..... that must have been a benefit!!! ... nitrous is fully hektic bro!!

[twocool]

Really great movie...one of my all time favorites!

Actually it was Nitroglycerin....heart medicine....(but the same stuff they make TNT and other explosives out of).......

Then again, in our RC model airplanes we use up to 60% nitro methane (40% methanol)

Cookie

I still reckon Old Bert from "worlds fastest Indian" was onto something.... he dropped half a nitrous oxide heart tablet into the tank before that run didnt he?..... that must have been a benefit!!! ... nitrous is fully hektic bro!!

[Janx101]

my bad!.. this morning i could remember nitro-something-ma-jigger 

always been curious if that concept had or has any basis to it... hmm 

[twocool]

I think it may have just been a "gimmick" to make the movie more interesting...don't know that he actually did that in real life..

Cookie

my bad!.. this morning i could remember nitro-something-ma-jigger 

always been curious if that concept had or has any basis to it... hmm 

[slipperymongoose]

How bout a bottle of whiskey in the diesel tank to thin the mix to give an extra 50rpm like in down perriscope!

[Janx101]

How bout a bottle of whiskey in the diesel tank to thin the mix to give an extra 50rpm like in down perriscope!

i suppose that is on topic... http://www.thedieselstop.com/forums/f33/whiskey-38979/

but this from the same movie is funny!!

[Zithromax]

I do have a comment about getting fuel from some particular places. The less volume a specific fuel station does, that amount of condensation (depending on climate and weather conditions) tend to add up in the tanks. Low fuel use = more condensation forming in tanks. I live in the dirty south, there have been issues. But by far and large the WORST thing that's happened to me was filling up while the tanker was delivering fuel. EVIDENTLY all the crud and rust on the bottom of the tank is kicked up and the pump must not have had an adequate filter, I got a tank full of gunk that barely burned and I ended up taking it to a shop getting a new fuel filter as well.

I guess new places have stainless steel tanks and better filtration, just something to be on the look out for at a local "mom and pop" shop out in the boonies.

[Janx101]

now then .. condensation loaded or dirty or old & cruddy ground tanks.... that would make a difference ! .. no matter what BRAND .. .... someone could go to a texaco in the boonies.. with cruddy tanks ... get a load of crudded fuel ... and from then on 'texaco' is crap fuel! .. 

[nutmunk]

How bout a bottle of whiskey in the diesel tank to thin the mix to give an extra 50rpm like in down perriscope!

As I mentioned earlier, I have run a two-stroke on whiskey-oil mix before...and it did work. No real increase in power..engine just idled a little high and gave off an awesome exhaust smell. Was just for fun...but it DOES run a motor. So there is a little truth to it...

[ohgood]

How bout a bottle of whiskey in the diesel tank to thin the mix to give an extra 50rpm like in down perriscope!

As I mentioned earlier, I have run a two-stroke on whiskey-oil mix before...and it did work. No real increase in power..engine just idled a little high and gave off an awesome exhaust smell. Was just for fun...but it DOES run a motor. So there is a little truth to it...

you're awesome. I'm going to dream about whiskey 2 strokes tonight.

[nutmunk]

hey...if not, why not...it was just to see if it did actually work.

On topic though I will say this...in the gs, I haven't noticed any difference between 97 and 93. However, I also have a scooter. Because the scooter has a 4 litre tank, it's not hard to finish off a tank of gas quickly. I fill up at the same petrol station up the road from me every week on a Thursday and it takes me exactly a week to finish off a tank of gas. The fuel is sasol...locally manufactured from coal. I drive the same route every day to work. Because it's a scooter, I spend most of that ride with the throttle wide open. The scooter is not limited by anything other than the gearing and the weight of the bike (no electronic limiters etc in the cdi).

Now...having said all that...of I put in 93, she maxxes out at 80-85km/h. If I put 97, she hits 90. Not to say that the speedo is accurate, but it does get me an extra 5km/h.

Not only that, but I have also noticed that on 93, I average about 85km per 4 litres...which I know isn't great, but it's because I spend most of the ride in stop-start traffic. When I put in 97, I can rode for an extra day on the weekend and do an average of 93-95km on a tank.

Now, I realise that this could speak volumes about the quality of the 93 petrol available over here more than it does about octane rating, but it is the reason I use ONLY 97 in my vehicles. Or whiskey once.

[Zookmang]

For the last year I've been trying pretty much every type of petrol available to me, and I really find no difference in my GS. She likes 91 just as much as the 98 vortex fuel i put in it once, which is handy cause 98 is bloody expensive. I do however sometimes wonder about carbon buildup from lower octane fuels but i guess you'd be rebuilding the thing before it killed your engine, no?