Home brew and warranty

[GMorg]

My GM owner's manual tells me that I must use a GF-4 5w30. I am becoming a believer that as long as UOA looks good, then thinner is better. If I combine GF-4 oils of different viscosity grades such that the final mix would still be 5w30 (Mobil 1 5W-20 and Mobil 1 5w30 for example), then am I technically still using 5w30 for warranty purposes? Alternatively, if I mix otherwise acceptible GF-4, 5w30s, have I just made a mut oil that has no certifications at all?

 

[Al]

Just keep a record of dates, milage and do what you want. There is no required "Standard" that is required to prove what you did.

Your only problem would be if the engine gets screwed up bc you used the wrong grade. I wouldn't get carried away using a thinner grade than recommended. BTW a 5w30 oil will thin from 8 to 8.5 cSt within a couple of thousand miles. So you are down to a 20 wt. anyway.

 

[Ken2]

How will you document your oil change for warranty purpose? You need some way to document that you actually did change the oil when the oil life monitor said to change it.

In any case, all the oils are so good that you likely can not improve on an oil. Just use all the same oil of your choice and be happy.


Ken

 

[D Bone]

vad: US Syntec is made from raw material that cost 30% less than Mobil's PAO. This difference isn't there for the consumer.
I'm a Castrol user myself but Castrol's got to do something about their pricing.


Maybe Castrol uses 30% more additives than Mobil, so the price is in fact equal.

D Bone

 

[burnout]

I think you replied to the wrong topic.

 

[farrarfan1]

Did you call GM and ask them?

 

[GMorg]

farrarfan1,

No, I did not ask GM. Their manual clearly states to add only API approved GF-4, SAE 5w30. I think that adding 5W-20 would be adding something other than 5w30. However, none of this really matters unless I have a lubrication related problem.