Engine calls for 5W-30, they put in 0W-20, does it matter?

Grumpy Bear · April 30, 2018

I run 5W20 in my 2015 4.3 year around. 60K. No issues. No oil usage....ever. I do run a colder thermostat. The 4.3 is a 5.3 with two cylinders removed. Can't think of a single reason it should be a bother. If it is fine for the 5.3 it should be fine in her little sister.

HondaHawkGT · May 9, 2018

On 4/28/2018 at 3:27 PM, weeniedawg said:

I know that the 2014-2018 trucks with 5.3 and 6.2 engines "require" 0W-20 oil, yet the 2014-2018 Corvettes recommend 5W-30. This doesn't make a lot of sense unless the trucks get better gas mileage on the EPA cycle with the thinner oil. The Corvette's engine is virtually identical except the 5.3 has smaller pistons. The valve lifters are identical on the Vette and the trucks as are the bearings and many other moving parts. How could using 5W-30 in the pickup cause any damage? I live in Florida, not Alaska. I just have this thing about water thin motor oil.

I've ran 5W-30 in mine in the summer time. No issues. Since GM used 0W-20 in the 5.3 and 6.2 during EPA fuel economy testing, they are required by law to spec 0W-20 for those engines. The one thing I noticed is that the oil pump is ever so slightly noisier with 5W-30 when cold. I'm assuming the noise is due to the vane-style,high volume oil pump. They have a reputation for having a whine noise.

qwank · May 12, 2018

I run 5w-30 in mine, the LT1 and LT4 use it, and the engines are basically the same specs.

Cowpie · May 20, 2018

On 10/29/2017 at 6:20 PM, Black02Silverado said:

No problems at all. I wouldn't rush out to get it changed. Just keep an eye on your oil level. If it were me, I would just keep an eye on the level and change it out at 3k.

I've ran 5w-20 in my 02 for 5k miles and the UOA's were all good.

Yeah, having 20 weight in there instead of a 30 will probably make no difference for average driving.. There is only a 3 pt spread in viscosity between them at full operating temperature. If I were towing heavy in Death Valley or over Vail Pass in the summer I might be more concerned.

The factory remanned 2000 MY Detroit Diesel 12.7 I have in a 2013 semi truck, the standard recommendation is 15w40. I use a 10w30 in it year round and it regularly has to move upwards of 80,000 lb of truck and cargo. The motor now has 838,000 miles on the reman and the UOA's look as good as when it only had 50,000 miles on it. And in only "uses" about 1 qt of oil in 11,000 miles. And I take the oil changes 50% longer than the OEM recommendation.