I owned a 2015 and 2016 Yukon Denali 6.2. I never used premium and they ran perfectly for many miles. Hope that helps.
the 15 and 16 are direct injection LT I believe right?
totally different engine to the older Gen 4 6.2. but I don't own either, just what I read from here and the owners manual. I have an aluminum 6.0L designed to run on 87.
cracked ring lands and stuff after 120k miles or so on 87 is what I read. I'm sure that depends on how it's driven, what Temps it see, ls hate at intake air Temps and all kinds of stuff. 87 in the winter vs 87 in the 115deg summer days are 2 totally different things plus different blends be region, even different stations can be different.
knowing me I'd probably be logging timing retard in hpt and trying to tune around it anyway possible, as 93 in a daily is kinda annoying these days that it's over 1$ more. wasn't so bad when it was 30cents more. those days seem long gone. diesel is now somehow cheaper than 93. I never thought it'd see that day.