Kindly explain how GM's warranty is better or would be better? Dealer install is a wildcard here as well. But IMO we are not going to the dealer for repairs in this discussion.
As I recall "Old Bankrupt GM" AC Delco is 12 months 12,000 miles then F.U. I have attached the modern AC Delco warranty and it's 24 months on Glow Plugs.
Maybe a courtesy warranty credit is available, but, already been down that road, in the early 2000's, with a GM dealer over their P.O.S. R4 compressor on dad's Yukon that expired by 1 month not miles. (Area rep only looked at it because fleet of ~600 GM pickups was dad's day job and the fleet shop loaned him the tools to install the R4.) After that we paid $$$ GM dealer to replace AC Compressor for the then lifetime repair warranty. Not sure GM Goodwrench (Modern day "Who is Goodwrench?") offers that anymore... And I now own my own AC equipment. Reference to the warranty from the "Old Bankrupt GM" "then" attached.
Same dealer ate (or GM helped them eat) a fleet pickup transmission replacement that broke a band under the courtesy warranty. Oddball low mile failure.
Different area of the country: Had a shop drop in a GM crate reman 4.3 V6 engine via an extended vehicle warranty contract I almost didn't buy. (And no it was a used Lemon unlike Patch that isn't. No, really. ) It had a loose lifter knock on install. Shop said I had to take it to the GM dealer for warranty. Should have, but, fixed it myself instead. Shop couldn't touch the engine itself due the warranty requirements. Only used that shop because local GM Dealer couldn't figure out main bearing knock with a oil pan full of metal shavings. Yeah, fixed the lifter knock myself because: Morons at
that GM dealer. (You got to drive to get a good dealer service center sometimes.)
Today warranty looks like this.