Compression ratio is thedeciding factorfor premium gas. The Tahoe falls into theRegular gascategory comfortably. Premium once in a while, as stated before is fine. Steady diet is uncalled for.
My GTO, which I just sold for the Tahoe, had 11:4 -1 compression and required 93 octane. The Tahoe is not even close to that.

 

You can't even make that blanket statement. On trucks like these, sure, but there are plenty of low compression ratio engines that require high octane fuel. The obvious example is forced induction applications, but my Viper runs only 9.6:1 and it still requires 93 octane. In lower compression situations timing is retarded so much that the air-fuel mix experiences quite a bit of compression prior to spark ignition, thus requiring the higher compression tolerances of higher octane fuel.

If you wanna really make your head spin, start looking at the newer variable compression ratio engines that can occasionally peak at 17:1... yet drop as low as 7:1...

 

well learn something every day.....