5w20 weight major brand oil and AC/Delco or Purolator filter would be my advice. I personally use Pennzoil oil. Check your owners manual to be sure on the weight.
5/30 or 10/30 and fully sintethic platinium
The 2006 GMC Savana runs on regular unleaded.
The 2006 GMC Canyon runs on regular unleaded.
The 2006 GMC Yukon runs on regular unleaded.
The 2006 GMC Sierra-1500 runs on regular unleaded.
The 2006 GMC Savana-Cargo runs on regular unleaded.
The 2006 GMC Sierra-2500HD runs on regular unleaded.
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The 2006 GMC Yukon-XL runs on flex-fuel (unleaded/E85).
It should use 5W-30. It will say on your oild cap, but that is probably what is recommended.
Factory says----5W30 in the winter time. Be sure to use A/C delco oil filter.
The 2004 GMC Savana runs on regular unleaded.