octane

[RX_rider]

how much octane are you spose to have in your gas. and what difference does it make to your machine by not having much octane in your gas?

 

[MR.HAPPY]

89 IS ALL YOU NEED FOR A STOCK SLED!!!

STOCK BEING NO MOTOR WORK!

BR

 

[LazyBastard]

87 regular. Going any higher is a waste of money and will negatively impact performance (though not enough to be perceptable).

 

[RX_rider]

so what does it really do?? and what happens if theres not enough in there, if anything.

 

[Yama-Crazy]

87 regular. Going any higher is a waste of money and will negatively impact performance (though not enough to be perceptable).

I agree with LB 87 is all thats needed.

 

[MR.HAPPY]

YAMAHA MANUAL = 88 OCT. RECOMMENDED

I'M AFRAID YOU'LL GET BAD OR OLD GAS & NOT HAVE ENOUGH OCT. FOR THE LEVEL RECOMMENDED.

I BUY 89 OR BETTER!!!

JUST MY 2 CENTS!!!

BR

 

[impalapower]

87 regular. Going any higher is a waste of money and will negatively impact performance (though not enough to be perceptable).

Lazy, what were the exact details on why it is not beneficial to run high ocatane? You had a post once that talked about it and I couldn't find it. I'd like to copy it and show my neighbor. He thinks his RX performs better with high octane, I said different.

 

[Sasquatch]

87 regular. Going any higher is a waste of money and will negatively impact performance (though not enough to be perceptable).

Lazy, what were the exact details on why it is not beneficial to run high ocatane? You had a post once that talked about it and I couldn't find it. I'd like to copy it and show my neighbor. He thinks his RX performs better with high octane, I said different.

I don't know about Lazy but from my youth and playing with high performance muscle cars.

If you ran premium and timed your car for it ( advance till ping and back off a hair ) it performed well. But if you timed for regular the same way ( by ear ) and then ran premium you fuel mileage would drop and your performance would suffer. Not a huge amount but a bit.

The reason I was told was because the higher the octane the slower the burn. More octane needed more advance in timeing. By running premium when timed for regular what was happening is the bang in the cylinder was later than the motor could take advantage of and some was going out the exaust as heat instead of being used as push on the piston top.

 

[LazyBastard]

First... Yamaha says 88 for two reasons;
1) Thats regular in Japan.
2) Give it some slack to cover their as*.

Now, the higher the octane, the longer the carbon chain.

Technically, "octane" is a straight C8H18 molecule, but the refinement process is not particularly accurate. The octane RATING really just indicates how easily it burns, and is related to the average length of the hydrocarbon.

The longer the HC chain, the more energy it takes to ignite it.

When you're running an engine that is very high compression, you end up having higher compression TEMPERATURES, which can tend to cause the fuel to burn before it should. To deal with this, you use a fuel that is harder to burn... longer HC chain. Higher octane RATING.



Now there is a very severe problem with using too long of a chain.... if it burns too slowly, then it burns on its way out the exhaust port. You definitely don't want this as it can burn your valves. Aside from burning the valves, anything that burns on its way out is not contributing to downward force against the piston, which means less power.

 

[genesis]

only very high compression motors need high octane.....yu will get more power out of regular gas....wont hurt to run super.....but yu wont gain anything except yure engine will run a little cooler.

 

[smokeless1]

The higher the compression the more need for higher octane to prevent pre-ignition, or that ping that most of us can detect when you get a load of cheap gas. One or two tank full probably won't do much but over time it can damage your engine, especially a high performance engine, like the rX-1


Higher the elevation the lower the octane necessary to accomplish the task.

Modern engines use computer to detect this pre ignition condition and back the timing off to correct for it. Don't think the RX will do that, not sure.

Putting a higher octane rated fuel in than required is simply wasting money. Since fuel will ignite when spark happens, and not after. It is best to use octain closest to what is recommended by manufacturer. If you use octain lower than recommended, you can usually hear predetination (ping) which will tell you not to use that grade again.

No doubt 87 octane will be at least 87, and may well be 88 grade to make regulators happy.

So running super in your RX-1 is unnecessary, but won't harm it if you do. Just cost you more to run it.

 

[Sled Dog]

So would running a higher octane all the time require a hotter spark plug?

 

[Sled Dog]

I have run premium and regular and I have seen no diff in perfomance so I just run regular.

 

[LazyBastard]

It doesn't require a hotter plug, it requires a thinner head gasket.

 

[Stormbringr1]

First... Yamaha says 88 for two reasons;
1) Thats regular in Japan.
2) Give it some slack to cover their as*.

Now, the higher the octane, the longer the carbon chain.

Technically, "octane" is a straight C8H18 molecule, but the refinement process is not particularly accurate. The octane RATING really just indicates how easily it burns, and is related to the average length of the hydrocarbon.

The longer the HC chain, the more energy it takes to ignite it.

When you're running an engine that is very high compression, you end up having higher compression TEMPERATURES, which can tend to cause the fuel to burn before it should. To deal with this, you use a fuel that is harder to burn... longer HC chain. Higher octane RATING.



Now there is a very severe problem with using too long of a chain.... if it burns too slowly, then it burns on its way out the exhaust port. You definitely don't want this as it can burn your valves. Aside from burning the valves, anything that burns on its way out is not contributing to downward force against the piston, which means less power.

...Not to mention that it also causes the engine to carbon up...