octane rating discusstion

[Steeb]

FAYI: Higher octane gas does nothing different than normal octane gas in an engine that does not require it. Octane is a measure of how much pressure the fuel can withstand before it ignites (all fuel will ignite on its own under a certain pressure) If your engine has HIGH comression, then it may pre-ignite regular octane fuel, this is why high octane fuel is available...because it simply withstands higher pressures without spontaniously igniting. If your engine doesn't need it,..... then puting it in you car is like throwing money away..because it does nothing. High octane fuel does not burn cleaner, does not burn hotter, and does not burn "more evenly" You would be suprised if you asked around and found out how many people mindlessly fill up with high octane fuel...I have heard people say "high octane fuel makes your car last longer" or "it burns cleaner, or hotter, or better" when it doesn't....Im sure most of you guys already know this, but I think it is important for somebody who might not know this to learn and stop wasting money at the pumps....

i agree and id like to also add to it.

our (north america) octane rating formula is not the same as in other parts of the world. RON and MON octane rating is based on the composition of the gasoline. this is why we use RON and MON for our octane calculations. if you go to the gas station you will see (R+M)/2.

our CLC rating is based on RON and MON Ratings.
CLC= (RON+MON)/2
use the simple formula and choose your fuel octane accordingly.


as you can see:
91 ron = 83 mon = 87 clc
95 ron = 87 mon = 91 clc

http://www.refiningonline.com/Engelhard ... CR4_29.htm

most cars use 87 or 91 CLC octane. states that have 93 can charge a little more for 93 than they could if they sold 91. its the oil companies way of extracting as much profit margin as possible. most states still have 89 octane gasoline which is the same idea as 93 octane.

i do not know the octane rating formulas of other countries.

[hgallegos915]

hmm ok I use 91 octane on my ze american octane.. i dont think they sell more higher than that.

[max kl]

i supose n/a using the lowest octain you can is fine.
the safety of running 110+ fuel with boost or nos is a concideration.
when my fuel solinoid failed and i had 100 hp of nos with no fuel the 110 kept me out of detination.
another concideration is if you gas station gets a bad lot butying 93 is safer than getin 87 and it being crap from mexico rater wnder 80.

[Devlin]

If your engine has HIGH comression, then it may pre-ignite regular octane fuel, this is why high octane fuel is available...because it simply withstands higher pressures without spontaniously igniting.

the KLZE engine IS considered high compression, no?
10.0:1

so using a fuel that can withstand the higher pressure without spontaniously igniting is a good thing since it will ignite when it's SUPPOSED to. would that not make things run smoother and reduce the risk of damage?

I don't know about in the states, but in Canada Sunoco offers 94 octane (a couple no-name ones do too, but Sunoco's the big one for high octane)

[hgallegos915]

I think well in ther ze, if regular octane is used, it wont detonate however... the knock sensor will detect as soon as it starts doing it and it will retard the timing. I think it can be run but not recommended. My plugs where just fine when I used regular for a week, I did feel a bit of sluggish power out of the engine. when I used 91. Felt nicer. Maybe its just me i felt it run better this way.

[Steeb]

If your engine has HIGH comression, then it may pre-ignite regular octane fuel, this is why high octane fuel is available...because it simply withstands higher pressures without spontaniously igniting.

the KLZE engine IS considered high compression, no?
10.0:1

so using a fuel that can withstand the higher pressure without spontaniously igniting is a good thing since it will ignite when it's SUPPOSED to. would that not make things run smoother and reduce the risk of damage?

I don't know about in the states, but in Canada Sunoco offers 94 octane (a couple no-name ones do too, but Sunoco's the big one for high octane)

good question! by modern standards 10.1:1 is not that high. i can list several engines that are 10.1:1 and higher, these engines come in econobox's that use 87 octane.

using higher octane fuel than normal rating will create more carbon build up in your combustion chambers than filling up with the proper octane rating.

[hgallegos915]

so what is considered best fuel for ze?

[mitmaks]

so how come higher octane fuel seems to last longer than lower octane?

[johnnyb]

91 octane is the required octane for a ZE.

Its 102 in japan so when you do all the conversions it adds up to 91 in North America


EDIT: Might I also point you guys into the direction of the octane FAQ I posted a while ago that'll give you tons of answers. FAQ: Octane rating and what it means

[max kl]

so how come higher octane fuel seems to last longer than lower octane?

what do you mean last longer?
do you mean it can be stored longer or you get beter mpg?

[Steeb]

91 octane is the required octane for a ZE.

Its 102 in japan so when you do all the conversions it adds up to 91 in North America


EDIT: Might I also point you guys into the direction of the octane FAQ I posted a while ago that'll give you tons of answers. FAQ: Octane rating and what it means

being that the mx6 or the milennia was not a "high performance car" or "sports car" i seriously doubt that it used 102 in japan. cars like the milennia were made to compete with cars like accords, avalons, camry's, diamante, and maximas... mid sized family cars which all use 87 octane at the time (most are still able to use 87 in the current models).

the link you posted is very good for newer cars preprogramed to run different maps for different octane gasoline. programing the ecu to run different maps for different octane did not start till the kl was reaching its product life cycle and it was not mazda that implemented this practice. in fact mazda still does not put that method of ecu programing to use.

only a handful of brand new cars utilize this method of multi target marketing. a few newer cars are programed this way because it is a good way to attract people looking for more performance as well as the people looking for economy.

if you have a owners manual from a car that originally had the klze id definately like to see it as would everyone else.

not a personal attack but i feel that the faq you linked should remain within the generation of maxima that it was tested on.

[mitmaks]

what about octane booster

[jschrauwen]

How about I let you put your hand near my Ducati engine when I put 130 AvGas in it at the track or even the 106 octane. Runs hotter and runs faster too. That's on an engine designed for 91 octane. When running the K8 I used 94 octane for 10 years and always had excellent looking plugs when it was time to change them out. Now I've seen other MX's who are not that concerned with what octane they used and there is a noticeable difference when pulling the plugs. I guess you could show me all the facts and figures out there but seeing is believing to me. Perhaps I should throw in the fact that for 9 years I towed my motorcycle on a trailer on my K8 and the times when I couldn't get the higher octane on some trips, there was a noticeable performance drop when pulling the trailer to the point that the slight hint of pinging could be heard when traversing up hills (the Rocky's) with the trailer. So to me octane did and does make a difference. My $.02

[hgallegos915]

well I stareted using high octane and now got better mpg. Feels a tiny bit stronger. With regular it felt as if the timing was being retarted. Im gujessing because of detonation.