Is 5w-30 mobil 1 safe to run for a 2014 5.3L Sierra?

chevy2tuff2006 · June 9, 2017

Is it safe to run 5w-30 mobil 1 in a 5.3L sierra all year, even in the Wisconsin winters?

Justin101714 · June 9, 2017

It too sure about winter there. I know the 0W-20 is basically to make sure all the small galleries for the engine get some oil.

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O_J_Simpson · June 9, 2017

gone_fishing · June 9, 2017

Absolutely safe

Coles5515 · June 10, 2017

In my 2012 I ran Amsoil 5w30 and it was fine, I won't why these new motors say 5-20...

mookdoc6 · June 10, 2017

Huh? No, absolutely not! only the 4.3L ecotec is allowed in WI...........your fine dude! It would probably sound real nice on 50

SirManny · June 10, 2017

Simply put no. Just run 0w-20

NomadicCPO · June 10, 2017

Simply put yes. The difference between 0W and 5W is negligible at cold start temps. At operating temp your engine wouldn't care either...except for the .1% fuel economy penalty.

powerhaulic · June 10, 2017

Yes it will be fine, and quieter on cold start too..

newdude · June 10, 2017

Is it safe to run 5w-30 mobil 1 in a 5.3L sierra all year, even in the Wisconsin winters?

Too much confusion above.

2014+ up 5.3 and 6.2 engines require 0w20 engine oil. Run 0w20.

Sierra706 · June 10, 2017

Safe? Yes. Ideal? Possibly not

I'm no petrochemical engineer, but I've seen some pretty detailed and factual posts here explaining how the differences are negligible at most operating temperatures we see here in the continental US.

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Cowpie · June 12, 2017

It is fully safe to use a 5w30 in that engine. Sure, it may not be warranty safe, but even that is likely not really an issue. Many fleet buyers use the same 5w30 even in the new Ecotec 5.3 as they do in all their other fleet vehicles with nary a problem and no grief from GM. Even the tightest oil galleries are hundreds of times larger than the molecules of a 30 wt oil. Even bearing clearances, even under pressure, are several microns larger than even a 30w motor oil. And a 5w20 flows just as easily at start up as a 0w20 unless one gets in the double digit below zero temps. A 5w20 and a 0w20 are virtually identical. And there is no dealer or OEM on the planet that can tell the difference if they took a used oil sample.

There are too many other things in life to worry about than whether a 5w30 can be used in a engine that calls for a 0w20. And in Wisconsin, a 5w30 will work fine down to -23F. If one is expecting colder than that, a 0w30 would probably be better. I live in Iowa and use 10w30 year round. But my vehicles sit in a heated garage during the winter when not in use. Someone is going to have to find the memo that a 10w30, even a conventional one, will not work in the 3.6L engine in the wife's 2006 Cadillac CTS. GM felt that only M1 5w30 synthetic should be used. Somehow, that engine never got the memo, and that the Pennzoil 10w30 conventional won't work. Runs like a champ and we are keeping that 12 year old car for a lot longer.

And what it really comes down to, regarding dealerships, is treat them just like you would the police. Don't open your fat mouth and proclaim you are doing anything else but following the recommendations. And as for receipts, just explain that you buy oil in bulk and don't have the receipt. I buy all of my oil thru my commercial account with my oil supplier and there is no way they could tell what oil I put in the pickup from that invoice if they wanted to. Any invoice I would present them would have a bunch of different oils shown in the purchase. And my GM engines have never seen a official dexos1 approved oil in their life outside of the factory fill.

powerhaulic · June 12, 2017

I have been using 5w-30 full syn dexos bulk oil since first change (900mi).

The only thing that is different is the engine is now silent on cold start, vs using 0w.

Engine used 1/2 qt or a bit more in 5000mi when new, now at 13000mi it used no oil at all at last change.

it is amazingly quiet at hot idle even after a full day towing 9000#

KARNUT · June 12, 2017

What does GM know, I sure wouldn't go buy their recommendation. It's not like they built them. I follow the manual till the warranty is up.

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NomadicCPO · June 12, 2017

What does GM know, I sure wouldn't go buy their recommendation. It's not like they built them. I follow the manual till the warranty is up.

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I would not "buy their" recommendation either, I got enough bills. Lol.

What GM does know is CAFE. That, above all else, is what is driving the trend to thin oils.