New LS owner...oil questions..Dexos 1...

[bandit0067]

Not sure if posted in correct forum , Mods move if needed. Guys, just bought my first truck/LS engine, a 2013 Tahoe. Owners manual says, 5w 30w only , NOT 10w 30w, why is this? I understand 10w is a bit more thicker and mileage may be less, but I have never seen it written that strong not to use. Is it a big problem to ALL LS engines or just the year[s} I have.

I trying so read up on this recommended Dexos 1, what is it , a new additive. What EXACTLY does it do for the engine that the manual says NOT using will void warranty. My truck is used so warranty is not a factor but do wish to prolong engine as best as possible. Do all LS engines need this Dexos 1 or just my year[s]. Is this Dexos just a way to put money in GMs pocket come oil change time in their millions of engines.....thanks for your opinions....