# What grades of fuel are commonly available in the US? **URL:** \ **Category:** Factual Questions\ **Created:** [August 17, 2002, 3:12am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287 "2002-08-17T03:12:14Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [August 17, 2002, 3:12am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/1 "2002-08-17T03:12:14Z")
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. ---
**Author:** ![Ms2001](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/ms2001/32/18463_2.png) [@Ms2001](https://boards.straightdope.com/u/Ms2001)\ **Post date:** [August 17, 2002, 4:02am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/2 "2002-08-17T04:02:20Z")
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. ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [August 17, 2002, 4:45am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/3 "2002-08-17T04:45:41Z")
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? ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [August 17, 2002, 4:55am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/4 "2002-08-17T04:55:55Z")
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](http://www.repairfaq.org/filipg/AUTO/F_Gasoline6.html#GASOLINE_001) ---
**Author:** ![Richard\_Pearse](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/richard_pearse/32/13144_2.png) [@Richard\_Pearse](https://boards.straightdope.com/u/Richard_Pearse)\ **Post date:** [August 17, 2002, 5:11am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/5 "2002-08-17T05:11:51Z")
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. ---
**Author:** ![Ell](https://avatars.discourse-cdn.com/v4/letter/e/e47774/32.png) [@Ell](https://boards.straightdope.com/u/Ell)\ **Post date:** [August 17, 2002, 5:19am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/6 "2002-08-17T05:19:38Z")
**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. ---
**Author:** ![Hilow](https://avatars.discourse-cdn.com/v4/letter/h/c4cdca/32.png) [@Hilow](https://boards.straightdope.com/u/Hilow)\ **Post date:** [August 17, 2002, 5:30am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/7 "2002-08-17T05:30:27Z")
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. ---
**Author:** ![Big\_Kahuna\_Burger](https://avatars.discourse-cdn.com/v4/letter/b/e0b2c6/32.png) [@Big\_Kahuna\_Burger](https://boards.straightdope.com/u/Big_Kahuna_Burger)\ **Post date:** [August 17, 2002, 6:55am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/8 "2002-08-17T06:55:33Z")
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. ---
**Author:** ![Wikkit](https://avatars.discourse-cdn.com/v4/letter/w/c0e974/32.png) [@Wikkit](https://boards.straightdope.com/u/Wikkit)\ **Post date:** [August 17, 2002, 7:36am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/9 "2002-08-17T07:36:06Z")
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. ---
**Author:** ![Saint\_Zero](https://avatars.discourse-cdn.com/v4/letter/s/c4cdca/32.png) [@Saint\_Zero](https://boards.straightdope.com/u/Saint_Zero)\ **Post date:** [August 17, 2002, 1:15pm UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/10 "2002-08-17T13:15:56Z")
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. ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [August 18, 2002, 2:55am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/11 "2002-08-18T02:55:37Z")
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. ---
**Author:** ![Wikkit](https://avatars.discourse-cdn.com/v4/letter/w/c0e974/32.png) [@Wikkit](https://boards.straightdope.com/u/Wikkit)\ **Post date:** [August 18, 2002, 4:35am UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/12 "2002-08-18T04:35:22Z")
> [@](#): > > \*Originally posted by Balthisar \* > **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.** Why? ---
**Author:** ![Balthisar](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/balthisar/32/2825_2.png) [@Balthisar](https://boards.straightdope.com/u/Balthisar)\ **Post date:** [August 19, 2002, 12:32pm UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/13 "2002-08-19T12:32:55Z")
> [@](#): > > \*Originally posted by Wikkit \* > \*\*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. ---
**Author:** ![scotth](https://avatars.discourse-cdn.com/v4/letter/s/b9e5f3/32.png) [@scotth](https://boards.straightdope.com/u/scotth)\ **Post date:** [August 19, 2002, 1:29pm UTC](https://boards.straightdope.com/t/what-grades-of-fuel-are-commonly-available-in-the-us/124287/14 "2002-08-19T13:29:10Z")
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.)