In Australia and New Zealand premium fuel is 96 octane and the non-premium* is 91 octane. From other threads I gather that in the US premium is 93 and non-premium is 87, is this true? Why is there a difference? How does this compare to other countries?
*Commonly reffered to as “unleaded” because it was the first grade to go unleaded. Both grades are now unleaded.
In Spokane I usually see 87, 89, and 92. I suspect the difference between regions is due to altitude or climate… if the environment is more likely to create spontaneous detonation (hotter or more oxygen-rich) you’ll need more octane.
I guess Australia fits into the “hotter” requirement. The tourism department would probably say that NZ is more oxygen-rich than anywhere else in the world :). I suspect that NZ probably just gets the same grades as Australia but I’d be interested in a definitive answer as to why the grades are higher than in the US.
What grades do you get down south in the hot parts of the US?
As Mr. 2001 noted octane for gas in the US come in three flavors 87, 89, and 91.
However before anyone complains that the Aussies get all the good gas, a question has to be answered. What method do the boys down under use to calculate octane?
There are two measures Research octane number [RON] and Motor octane number [MON]. The US numbers are the average of MON and RON.
I don’t know how fuel is rated down under.
Here is a site that will tell you more than you ever needed to know about octane
Ok, it seems that we use RON which gives a higher number than MON so the fuels are probably similar. Also, some fuel here is 98 RON apparently.
Skogcat, I’ve always heard that we get crappy fuel here in Australia and the car manufacturers have to actually tune down the cars to work with our fuel. I think Japan has good fuel.
The reason there is a difference in the octane levels between countries is that we get our fuel from different places.
87, 89, and 91 are not universal in the United States. In Utah the numbers are 85, 87 and 91. I am not sure why. It irritates me though, because my Honda sedan requires 86 according to the owner’s manual so I end up paying the mid-level price.
In Connecticut it’s 87, 89/90 and 92/93. We also have the biggest gas tax in the nation, making it very pricy. My car needs premium and I have to pay 26 to fill it up. 86 is considered stuff you only put in rental cars, and I only saw it in the Midwest.
In Iowa, it’s usually 87/89/91 or 92. 89 is 10% ethanol with the implication of being made from Iowa corn, and due to government subsidies is the same price as 87. We use the (R+M)/2 method of octane calculation.
Remeber folks, if you run your pulse jet engine on gasoline, use low octane.
Southern Doper, here.
I’ve seen mostly 87, 89, and 91 octanes. All figured using the (r+m)/2 method. Now, BP usually advertises they sell 93 octane in some places.
Now, for a real blast, watch old episodes of Adam-12. I nearly cried seeing stores selling 98 octane for like, $.25 a gallon. And Leaded to boot. Like going back to my childhood.
Around here “economy” is 86, and only certain stations (e.g., Sunoco) have it.
Most gas stations are 87, 89, and 91 or 93 – this latter about half-and-half.
If anyplace indicates they have 10% ethonol, I avoid it. If I’m already in the middle of pumping, I stop and pay what I owe and go someplace else.
Around here the premium is about $0.20 more per gallon, but my car recommends it. A 19 gallon tank is about $4.00 more per fillup – hardly noticed, and more passing power.
Why?
Because it’s the same price as real gasoline. If it were 10% cheaper to reflect the fact that it was 10% adulterated with corn mash, I’d consider it. I know it’s safe for the car - I’m not superstitious about the quality or anything in this day and age. But I can’t help but feel they’re trying to “put one over on me” by selling me their unwanted merchandise. It’s like buying Coca-Cola and finding out you got duped with a corn-syrup version instead of the cane sugar version.
It also depends somewhat on which fuel store chain you visit. Many places do the 87/89/92 combo, but Exxon and Chevron (in the Dallas, TX area) usually carry 87/91/93. I generally run the 93 octane. If I stick to those brands, I usually do a pretty good job of locating 93 octane while on the road around the country.
I know of a few shop near Indianapolis, IN that offer grades up to 100 octane, but it is pretty expensive. (Anyway, they used to, it has been a couple years since I have checked.)