Boner,
I went back and read up on Octain ratings just to double check and I think you need to rethink your opinion that higher Octain coorilates to more power.
Check out this this gasoline FAQ page:
http://www.cs.uu.nl/wais/html/na-dir...faq/part3.html
It is very detailed but a summary section below sums up what I was trying to say which is that if your engine is not knocking with 89 oct fuel then 92 oct will be harder to burn even with 9:1 compression and you should not see any performance gain and possible you will loose performance.

"The antiknock ability is related to the "autoignition temperature" of the
hydrocarbons. Antiknock ability is _not_ substantially related to:-
1. The energy content of fuel, this should be obvious, as oxygenates have
lower energy contents, but high octanes.

6.13 Can higher octane fuels give me more power?
If you are already using the proper octane fuel, you will not obtain more
power from higher octane fuels. The engine will be already operating at
optimum settings, and a higher octane should have no effect on the management
system. Your driveability and fuel economy will remain the same. The higher
octane fuel costs more, so you are just throwing money away. If you are
already using a fuel with an octane rating slightly below the optimum, then
using a higher octane fuel will cause the engine management system to move to
the optimum settings, possibly resulting in both increased power and improved
fuel economy. You may be able to change octanes between seasons ( reduce
octane in winter ) to obtain the most cost-effective fuel without loss of
driveability.
Once you have identified the fuel that keeps the engine at optimum settings,
there is no advantage in moving to an even higher octane fuel. "

Take care,
-Charles

 

Good report Cromwell, High test is actually a slower burning more stable fuel allowing its use in high perf applications. It is also cooler burning than low test UNLESS you are getting detonation or spark knock in your engine. There is no power gain in high test except it's allowing you to modify your engine for performance.

 

I've seen a lot of good fuel debates on here over the last year or two. I think the Tree Farmer/Motorhead one was one of the best. I don't know myself exactly how it works, but is it possible you are both right? I know what Cromwell is saying is true, but I wonder if it is applicable at the higher octane levels than what would be stock-ie. 89-93 that you find in the gas pumps at the local service station. The reason I ask is after running a few tanks of regular 89 octane in the 'Cat, I switched over to superunleaded (93 octane) and noticed the same charactersitics Boner mentioned, as well as better fuel consumption. As a result, I only run super unleaded now. Same thing goes for in my own rice burner car-a '97 Honda Civic. Running 93 octane, I'll get between 38-40 mpg. Dropping down to regular, I get tops of 35 if I'm lucky. Same goes for our Suburban-I can get 12-15 mpg on supreme, yet I'll be very lucky to get 10 flat off the regular stuff. None of these engines have any pinging, and they are all completely stock.

This is where I'm confused-as "science" says I should not be noticing any difference between the different fuels under these conditions. However, in this case, science is wrong. I keep very close track of my mileage as I spend a lot of time on the road, and with the increased gas costs, I prefer to go as long between fill-ups as possible. Of the 5 cars in our family, 4 of them all have the same results using premium gas. The one that doesn't is an old Toyota car on a re-built engine with around 200,000 miles. Anyway, could this "science" be referring to jumping from normal pump gas of anywhere between 89-93 octane, clear up to high performance gas of 104+? Naturally, you would not want to waste your money on this high perf. stuff, as it won't do you any good-from the "science" above. This is what I can't seem to get through my buddies head-he rides a '01 YZ 250 with pipe and jet, runs only high perf. race gas that smells like pure alcohol. Damn that thing stinks. It runs perfectly well on normal 93 octane pump gas, yet he won't run anything but the 110 race gas stuff, at $7.00 a gallon!

Anyway, just curious,

Mike

 

Question, Seems to me that if the engine is running to rich that higher octane may not help. Since all the A/C's do run pretty rich from the factory, if you had one (carb.) adjusted right I would think the higher octane wouldn't hurt.

 

Hi guys. I have to go along with cowboy. My cat gets better performance on 93'as does my full size ford 4x4.More power (pulling and hiway speeds)with 87-89-oct the truck wants to run at 67,with 93 I have to watch it real close,it wants to run at 75.This is stock ford 302.Gas milage is 20+ on the hiway,cat gets about 12-15 on 89 18+ on 93.Just my penny.
Jim

 

<< 2002 Yamaha Grizzly 660
1999 Arctic Cat 500
>>



im really curious how these two compare. i own a '01 arctic cat 500. im almost certain to buy my wife a '01 sportsman h.o. but first i wanted to check out the new grizzly to see how it compares. any thoughts on it?
thanks.

 

Hardcore-
Check out any of Andy's posts about the new '02 Grizz. He picked one up not too long ago, and will give you about the straitest, most honest answer about anything you can think of, whether good or bad. Believe me, he doesn't sugar coat anything, his thoughts and opinions are definately worth listening too. Scan through his posts-I think there's about 3 pages now on his latest, should be plenty of info there for ya, I'm sure he'd be glad to help with whatever else you may need. Also, Irichard looks like he's come back recently, also trading in his 'Cat for the new Grizz. He is another great source for honest information about the Grizz.

Best of Luck,

Mike

 

<< also trading in his 'Cat for the new Grizz. >>



many thanks mike!
i do need to add one point for clarification incase it wasnt clear. i wouldnt trade my ACT suspension for _anything_ until something comes along that articulates better. the grizzly would be for my wife.......that or a sportsman.

 

Oops, sorry if I worded that wrong! Yeah, I knew you were keeping yours, just buying for the wife. What I meant was simply that Irichard had traded his 'Cat for the new Grizzly. Andy bought the Griz, but will be selling his 'Cat. Sorry if I sounded confused!

Best of Luck,

Mike

 

I think it is a co-conspiracy between the government and the gas stations because it seemed to me before all of this high priced fuel nonsense 87 octane gas was very descent gas and 93 was like airplane fuel however it seems to me not only are they bending us over on gas prices they are also giving us gas that sucks. My 77 cj7 wont run on 87 octane gas nowadays however back in the olden days (a couple years ago) it ran just fine in conclusion I believe you are both right the 93 runs better because it really is what the factory recomends however 87 is barely able to power a weed eater that is the only possible answer because you both seem finely schooled in octane explanation.