Proper Octane

I need a professional opinion.......I bought a 2004 TB LS in January of 2004. I have ALWAYS used 89 octane fuel and have never had a problem with it. She purrrrrrrrs like a fat kitten. But recently I was told that I should use 87 octane because I could damage my engine. Is this true? I thought the higher the octane, the cleaner the engine. Would someone tell me the proper fuel to use. $32K is a big investment for me to be doing damage to my engine. Thanks...
Kathy

The professionals, (GM) say 87 will be fine. As long as you use a major brand.

When you open your manual to page 3 it states clearly to use 87 octane. Why pay the extra cost when its not necessary. Also high octane will make it burn hotter.

a pro would read the owners manual

The manual is one thing....but no...you are not going to do any damage if you use a 89 as opposed to 87. In fact...some places use the same gasoline for both. The posted rating in the minimum octane...not the "true" octane.

The manual is one thing....but no...you are not going to do any damage if you use a 89 as opposed to 87. In fact...some places use the same gasoline for both. The posted rating in the minimum octane...not the "true" octane.


Thank you so much........
Kathy

The professionals, (GM) say 87 will be fine. As long as you use a major brand.


Thank You...
Kathy

Higher octane does not burn hotter, it burns slower to prevent pre-ignition. 89 octane would be ok for the trailblazer if you were straining the engine enough to make it ping with 87 and the computer was retarding the timing, then 89 would be worth the extra expense.

I live in the Middle East and the lowest grade octane here is 91 and that is what I run in my Trailblazer, and have had ZERO problems running 91 octane.

Thanks Chris

billqual - That's what I thought to, but I didn't have any information to back it up. My TB runs much smoother with 93 (Super). I only get it about once a month, but I definitely notice a difference in the smoothness, both at idle and during accelleration. Thanks for the more technical explanation.