# Mazda Millenia S

**URL:** <https://community.cartalk.com/t/mazda-millenia-s/17166>\
**Category:** Maintenance/Repairs\
**Tags:** millenia, mazda\
**Created:** [July 24, 2008, 10:50pm UTC](https://community.cartalk.com/t/mazda-millenia-s/17166 "2008-07-24T22:50:29Z")\
**Posts on this page:** 5\
**Page:** 1

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**Author:** ![Mazda\_Mom](https://avatars.discourse-cdn.com/v4/letter/m/e36b37/32.png) [@Mazda\_Mom](https://community.cartalk.com/u/Mazda_Mom)\
**Post date:** [July 24, 2008, 10:50pm UTC](https://community.cartalk.com/t/mazda-millenia-s/17166/1 "2008-07-24T22:50:29Z")

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this is a 6 cyl trubo engine…the owners manual recommends 91 octane gas…I am unable to find this and use 89 octane.  
  
 I have a problem with my check engine light coming on…when I add STP Octane Booster, my check engine light goes out.  
  
 It his harmful to my engine to add it with each tank of gas? thanks

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**Author:** ![NYBo](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/nybo/32/17281_2.png) [@NYBo](https://community.cartalk.com/u/NYBo)\
**Post date:** [July 25, 2008, 12:44am UTC](https://community.cartalk.com/t/mazda-millenia-s/17166/2 "2008-07-25T00:44:07Z")

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It’s harmful NOT to use the octane booster if it keeps the engine from pinging (and causing the “Check Engine” light to come on). Does the owner’s manual say 91 octane is recommended or is it required? Can you find 93 octane? BTW, if you live at high altitude, the engine’s octane requirement will be less.

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**Author:** ![hellokit](https://avatars.discourse-cdn.com/v4/letter/h/6a8cbe/32.png) [@hellokit](https://community.cartalk.com/u/hellokit)\
**Post date:** [July 25, 2008, 12:55am UTC](https://community.cartalk.com/t/mazda-millenia-s/17166/3 "2008-07-25T00:55:43Z")

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If you can find 91 or 92 or 93 octane gasoline, use that. If you can’t find any of these (curious), continue to use the octane booster. It’ll save your engine. With a turbo engine, you don’t want to blow it!

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**Author:** ![Joseph\_E\_Meehan](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/joseph_e_meehan/32/21_2.png) [@Joseph\_E\_Meehan](https://community.cartalk.com/u/Joseph_E_Meehan)\
**Post date:** [July 25, 2008, 10:09am UTC](https://community.cartalk.com/t/mazda-millenia-s/17166/4 "2008-07-25T10:09:22Z")

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You may want to just mix regular and a higher than 91 octane. That is what they would likely be doing at a station that was providing a mid grade.

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**Author:** ![lion9car](https://avatars.discourse-cdn.com/v4/letter/l/59ef9b/32.png) [@lion9car](https://community.cartalk.com/u/lion9car)\
**Post date:** [July 25, 2008, 5:08pm UTC](https://community.cartalk.com/t/mazda-millenia-s/17166/5 "2008-07-25T17:08:23Z")

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I’m curious. You must live in really high mountains if 89 is the highest available. Do you?