yeah that works... you can only buy oil the OEM specified manufacturers markets and sells at dealerships or your car/truck warranty is VOIDED
you can, bet the farm, the price per quarts quadruples and if you miss a single 3000 mile oil change the warranty is null & void
the average outside temperatures where you drive should have some influence on your choices in oil used,
here in florida as an example
most of the year we see 70F-90F
remember when chevy builds a car/truck and makes suggestions,
they don,t know if it gets sold in northern wisconsin , Alaska,
or Miami or Dallas
selecting a 10w30 or 5w30 works ok here in mid fla
at these temps oil is already easy flowing at engine start-up
http://garage.grumpysperformance.com/index.php?threads/viscosity-centistoke.15612/#post-93303
http://garage.grumpysperformance.com/index.php?threads/which-oil-what-viscosity.1334/
http://garage.grumpysperformance.com/index.php?threads/bearings-and-oil-flow.150/
