# Why is "Regular" 86 octane here?

**URL:** <https://community.cartalk.com/t/why-is-regular-86-octane-here/83249>\
**Category:** Maintenance/Repairs\
**Tags:** hyundai, sonata\
**Created:** [January 20, 2014, 10:15am UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249 "2014-01-20T10:15:18Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![art1966](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@art1966](https://community.cartalk.com/u/art1966)\
**Post date:** [January 20, 2014, 10:15am UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/1 "2014-01-20T10:15:18Z")

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Visiting my son in El Paso, TX. The Manual for his 2009 Sonata says “Use at least 87 octane.” Most places, that means “Regular” gasoline. But hereabouts the Regular is 86 octane, so he’s using the next higher grade. Why are they selling 86 as Regular?

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**Author:** ![Barkydog](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/barkydog/32/2470_2.png) [@Barkydog](https://community.cartalk.com/u/Barkydog)\
**Post date:** [January 20, 2014, 10:21am UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/2 "2014-01-20T10:21:29Z")

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That is news! I have never seen less than 87 octane, is there an ethanol % also?

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**Author:** ![jdmere](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/jdmere/32/3002_2.png) [@jdmere](https://community.cartalk.com/u/jdmere)\
**Post date:** [January 20, 2014, 10:44am UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/3 "2014-01-20T10:44:06Z")

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It has to do with altitude. At higher elevations it is common to have lower octane ratings since the engine operates as efficiently due to the lower air pressure. In the Rocky Mountain west this is not unusual to see at stations.

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**Author:** ![jtsanders](https://avatars.discourse-cdn.com/v4/letter/j/c2a13f/32.png) [@jtsanders](https://community.cartalk.com/u/jtsanders)\
**Post date:** [January 20, 2014, 12:45pm UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/4 "2014-01-20T12:45:03Z")

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+1 to @jdmere’s answer. El Paso is at 3200 ft above sea level.

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**Author:** ![JoeMario](https://avatars.discourse-cdn.com/v4/letter/j/3bc359/32.png) [@JoeMario](https://community.cartalk.com/u/JoeMario)\
**Post date:** [January 20, 2014, 4:59pm UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/5 "2014-01-20T16:59:50Z")

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Another +1 to @jdmere’s reply.

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**Author:** ![art1966](https://avatars.discourse-cdn.com/v4/letter/a/77aa72/32.png) [@art1966](https://community.cartalk.com/u/art1966)\
**Post date:** [January 20, 2014, 5:51pm UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/6 "2014-01-20T17:51:16Z")

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Ah! (I should have thought of that.) So, then, even though the mfr “requires” 87, he can actually use the 86 here? Just listen for pinging (or watch for CEL), and be sure to change upward if he is headed for lower altitudes?

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**Author:** ![missileman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/missileman/32/1366_2.png) [@missileman](https://community.cartalk.com/u/missileman)\
**Post date:** [January 20, 2014, 7:51pm UTC](https://community.cartalk.com/t/why-is-regular-86-octane-here/83249/7 "2014-01-20T19:51:56Z")

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Another +1 for @jdmere. I used to live in the high desert of Arizona and 85 octane was regular gas. My vehicles ran fine with 85 but I always filled them up with 87 octane while traveling in lower altitudes.