If your talking about engine HP output........yes it does. The colder you can get the intake track in a motor the more O2 it can hold and the more power you will make. That is why you want to pick up as cool of air as you can possibly can get. That is why you will see iced down intercoolers at the drag strip on blown cars.

Same way with the fuel. If you can keep the fuel cool, it will keep the intake track cool and you will pick up power. That is "some" of the reason alky makes a lot of power in hot conditions. In cool or cold conditions I can make almost as much power as the alky boys. In warm or hot conditions they will wax me.
Fuel coolers or cans as we used to call them were very popular years ago. I don't see them at the strip anymore. Why? I don't know. I used to use one at the strip but I don't anymore because of all the hassle. I had to have ice on hand and recharge the can if it was really hot. Also if I got lazy and the water got hot in the can it would throw the carb mixture off. I bracket raced so I didn't really care how much total power I made anyway. That is the reason I got rid of the can. Probably the reason I don't see them anymore?
Were talking very little HP gain for a lot of work anyway and there were much easier ways to make more power.

If you were talk about detonation, then yes, the temp of fuel and the air temp will effect that also. The hotter the fuel and air entering the engine the more prone to detonation the motor will be. The cooler, the less prone to detonation it will be.

 

My wifes car has a min 87 octane rating but when she puts 87 in it, it pings like a ping pinger. The dealers mechanic says it's fine to put 87 in it but if you don't like the pinging, put higher. He says the pinging won't hurt the engine.

 

Like basically everyone else here has said.......stick to 87 octane. I just wanted to add that the 450 will have a low compression ratio......probably something like 9:1 so there is absolutely no need for higher octane. I think it was Chris who stated what octane actually is correctly. Octane is an additive which actually retards combustion flash point. In a high compression ratio engine low octane fuel will detonate pre-maturely causing the pinging and run-on some of you may remember of cars in the 60s/70s if you used too low an octane. Higher octane stopped it. The higher octane retards the flash point so that it can be compressed more before it will flash (ignite). Pre-ignition is when it ignites without the sparkplug setting it off because the existing temp combine with the compression is enough to meet the flash requirements. Octane simply "ups" those requirements so the fuel will not ignite until the spark plug fires even with the higher compression.

 

If the plug is the wrong heat range, the tip will get too hot and ignite the fuel. Also, a damaged area of the cylinder wall will cause predetonation, if the spot/scrape causes added friction. So, each engine will have it's own requirements. My HO runs great on 87.

 

Stock outlaw compression ratio is 10.6:1 so mid grade would be suitable for that.

 

Thank you all your support! I have taken in all the facts. I'm learning. It maybe engine repair 101 for some of you, but I took carpentry & industrial technolgy during my early years. I found out early in life, I was all tumbs, but I was okay with a hammer (of course these days, people use nail guns). So I never mastered the combustion engine. Again thanks!

Another comment I got to say, Maine Mudder 3, I saw your web site and that's quite of a machine, the Yellow Submarine!!!! Tell me when you are running through the muddy water, if your engine stops does the White Brother pipe back fill in its vents? Do you have to seal your engine casings more? Seriously, I'm curious. Back to engine repair 101, if water gets in your pipe that's bad. My owners manual warns me not to drive in water above the foot pegs or get water in the pipe while washing it. I understand how the snorkle protects the air filter. This Outlaw I have is no Sportsman when it comes to extreme conditions, it's more of a desert racer. The reason I ask, periodically I do small creek crossings on trails.

 

You'll be fine on the creek crossings. You can go in fairly deep water with your outlaw with no problems. If somehow you ever do get stuck in water that is over your exhaust so it is bubbling, keep the bike in neutral and rev it a bit to keep it running..dont let it stall out. What I do is if for a day I know I'll be riding deep water I set my idle 500 rpms higher so if I do get stuck in deep water I can put it in neutral and let off and it will idles fine as I get it unstuck. Also here are some new pics of my bike...the ones you looked at are older ones-

http://photos.yahoo.com/sportsman500ho2003 Go to "Sportsman Rebuild"(copy&paste the link)

 

Thank you on the water crossing concern. I will go forward and conquer the crossings. Also, I will check out your new pics. LW.

 

I agree with 2manytoys.
I run 87 in my sp700 and min 91 in my scr400 (HPD recomended w/mods).

Some older cars may require higher octane if they ping and knock with 87 octane.
This was the case with my '78 Z28 I had.
Otherwise go with what the manufactuer recommennds...

Jim

Fuel For Thought
By Rich Rohrich
Part 1 - The Basics

http://www.eric-gorr.com/tech/tech_main.html

What does the Octane Number at the pump mean?

The octane rating of a fuel is what most people are familiar with, but there seems to be a lot of confusion surrounding it. In simple terms the octane number you see at the pump is the average of two octane numbers; the Research Octane Number (RON) and the Motor Octane Number (MON) or (RON + MON) / 2. This final octane number is sometimes referred to as the Anti Knock Index or AKI. This pump octane number is a measure of the anti- knock characteristics of a given fuel.

MON and RON are determined by standardized ASTM laboratory tests. The details of the tests are not as important as what they mean in terms of performance. Low to medium-speed knock characteristics are determined by the Research (RON) method, while high-speed and partial throttle heavy load knock characteristics are determined by the Motor (MON) method. MON testing is conducted under more stringent conditions with the timing on the test engine advanced and run with a higher inlet air temperature, so the MON number tends to be lower but also more valid for high-performance applications. There are a number of more valid tests that have been developed to determine the anti-knock characteristics of fuels used in high performance engines, but the aren’t in general use at this point so we are stuck with the old reliable pump octane number.

So what’s that knocking sound coming from my engine?

The Knocking sound you hear when your engine is in trouble are the result of abnormal combustion. The most common combustion problems are detonation and pre-ignition. In simple terms detonation is the uncontrolled burning of the fuel in the combustion chamber, while pre-ignition can be defined as the starting of the burning process by any source other than the spark plug usually before the plug has fired....

 

Now to throw another wrench into the situation...

What about oxiginated or non oxiginated fuels, a different octane rating is required depending on if it is oxiginated or not. (sp700 servise manual).

How do you get this info, its not on the pumps?? Is most sold to consumers oxiginated??

Jim