[dennisbible]

Apparently Hyundai has released a TSB that says the preferred oil is 5W40. Have you guys heard that?

 

[Exeno]

Why would they release a TSB for a recommendation that already exists in the manual? I checked for a TSB on the NHTSA website, and insofar as I can see, nothing for '18, '19, or '20


Hyundai also posts their manuals online:


https://owners.hyundaiusa.com/us/en/resources/manuals-warranties.html

 

[jetrep]

Apparently Hyundai has released a TSB that says the preferred oil is 5W40. Have you guys heard that?

Most cars are going to thinner oils I can't imagine why Hyundai would start suggesting 5W-40.


According to the manual: "For better fuel economy it is recommended to use the engine oil of viscosity grade 5W-30 (ACEA A5 or above). However, if the engine oil is not available in your country select the proper engine oil using the engine oil viscosity chart."


In case the chart is not visible, it shows 5W-30 and 5W-40 covering the same temperature range.

 

[GTF]

I think the TSB that most people reference is from a 2016 TSB. It isn't specifically a TSB for our cars because like Exeno wrote, 5W-40 is in the owners manual. Most aftermarket tuners recommend you use 5W-40 for better engine protection.

 

[GasseousClay]

The GDI engine definitely contaminates the oil faster...I have noticed that there is a gasoline smell in the engine oil.

5w40 wont hurt in the heat of the summer, anyways.

 

[GasseousClay]

I also read on the Korean hyundai forums that the gdi engine lowers viscosity of the engine oil.

 

[dennisbible]

5W30 is within spec and that apparently is for better fuel economy but 5W40 is preferred.

 

[Touring_tech]

5w40 may be a bit heavier when hot. But the difference in fuel economy will be negligible. Go for 40.

 

[dac21]

I also read on the Korean hyundai forums that the gdi engine lowers viscosity of the engine oil.

Probably from fuel dilution. In between oil changes the oil level rises a bit on my 2018 GTS.