daxman

Are there any affects on the engine of a 2006 Z using 87 octaine? How about 89? Is 93 the only one that should be used?

Cux350z

iTrader: (162)

never been discussed in 14yrs...or the 6+ that you have been a member

turboed350z

If you cant afford the extra .20 cents, get a civic or a prius. Even on the fuel door it says "premium only."

MicVelo

There was an octane thread just last week sometime.

Consensus: No, you should not run anything less than 91 (AKI...posted octane) in your car BUT, in a pinch, it's not going to hurt anything as the knock sensor/ECU circuit will do its best to retard timing to keep the motor from grenading itself from the inside out (and killing performance in the process) and with no long term effects.

Regular running of sub-standard recommended octane ratings can have long term detrimental effects but even so, those aren't generally fatal.

travlee

iTrader: (8)

what is the highest you have in cali mic?

MicVelo

91 R+M/2

Unless one buys gas at Mazda Raceway Laguna Seca or an airport...

turboed350z

Local circle k sells 110 for 8.99 a gal last i check...

Ill just stick to my 91 haha

travlee

iTrader: (8)

we have 89, 91, and 93 here

turboed350z

Elevation maybe? My whole state, highest is 91, minus the race gas. And other state has 93 so i can only think elevation is the main factor.

travlee

iTrader: (8)

maybe, we are only 480 feet above sea level

turboed350z

Im over 4k sea level so im pretty screw on power haha

sportbiketed

iTrader: (11)

*Octane

MicVelo

In your state, it's likely that the posted octane is based on RON ratings (research octane number) only.

Here in CA, posted octane levels are based on an average of RON and MON - or Motor Octane Number (hence "R+M/2") to describe our fuels.

What that means in layman's terms is that the "91 octane" in CA may actually be equivalent to the AZ 93 or higher since MON reads much lower therefore lowering the average between the two.

Not certain that's the case but it's probable. Next time you're at your respective gas stations, look at the posted octane sign. It will tell you for certain which number is used for the PON (posted octane number).

RONs MONs PONs... no mattuh, always use the highest one in a Z.

turboed350z

Thats interesting tibit. I read awhile back, that as elevation increases, it affect power in the motor and what not. And that are with high elevation tends to not have 93 octane for some reason in which i forgot.

But i find that statewide 91 is the highest we have and lowest elevation is around 2k. While area with sea level has 93. So im not sure what thats all about.

Out of curiosity, whats your elevation? Cause where trav is, he has 93 available with 400 elevation. So im starting to think, it has a roll in octane availability

MicVelo

Higher elevation, as everyone knows, has "thinner air" (lower density, lower ratio of oxygen); this leads to requiring less octane due to the lower density of the air/fuel mixture. (Effectively lowering engine compression and carrying with it a lower incidence of knock.)

So, in short, YES, higher elevation requires less octane levels as knock probability is already lower just based on your locale.

Trav's area at 400', mine at 80'-something are both effectively sea level. You have to go a fair amount higher for your car to realize any significant change in performance.

turboed350z

Hm so minus the MON rating youre effectively getting 93 octane. In theory of course.

Whichs makes sense at sea level. My state is 2k, at its lowest, above sea level and my area specifically is over 4k, so yea we only have 91, and it makes sense