No ... I would not.
Don't buy into the BS claims of increased HP & fuel efficiency, no spark plug will produce better results than stock A/C Delco Iridium plugs for your Envoy.
They may claim it will but I have never seen undisputed proof... matter of fact, the E3's aren't any better than any name brand iridium plug .. just better for the people who SELL them.

Huge ignition spark gains have been made since the day's when our vehicles used the old school points/plugs & condenser with 12 volts output coils vs. the high energy stuff of today .... they make it seem that you'll be installing lightening bolts ... but it's only hype.