Question on oil for a 2012 Acura TL SH-AWD

[MajorCavalry]

I have a question on oil for my brand new 2012 Acura TL SH-AWD. I was reading over the owner's manual and found this interesting tidbit. If the car is equiped with the 3.5L engine it calls for 0W-20 but if it has the 3.7L engine it recommends 5W-20. There is no mention regarding the 3.7L engine that 0W-20 is an acceptable alternative and the oil filler cap lists 5W-20.

If the only difference between the oils is the cold temp viscosity, then why would they differentiate between the two engines? I realize they may not have updated the 3.7L engine with low tension rings, etc but I thought it odd that they still recommended the 5W-20 oil.

Any thoughts?

 

[rjacket]

Originally Posted By: MajorCavalry
I have a question on oil for my brand new 2012 Acura TL SH-AWD. I was reading over the owner's manual and found this interesting tidbit. If the car is equiped with the 3.5L engine it calls for 0W-20 but if it has the 3.7L engine it recommends 5W-20. There is no mention regarding the 3.7L engine that 0W-20 is an acceptable alternative and the oil filler cap lists 5W-20.

If the only difference between the oils is the cold temp viscosity, then why would they differentiate between the two engines? I realize they may not have updated the 3.7L engine with low tension rings, etc but I thought it odd that they still recommended the 5W-20 oil.

Any thoughts?


It really needs 2.5w-20

 

[JAG]

Maybe they are concerned that some 0W-20 oils are not as shear stable as 5W-20. Or maybe it's because 0W-20 does not have to pass the TEOST 33C test to meet API SN while 5W-20 does.

 

[road1will]

You can run 0W-20 an either of the 2012 TLs.

 

[MajorCavalry]

Originally Posted By: road1will
You can run 0W-20 an either of the 2012 TLs.


If this is the case, why would the owner's manual specify different oils? For the 3.7L , 0w-20 is not even suggested as an alternative.

 

[MajorCavalry]

No experts that can explain this?

I had thought that it was the high temp viscosity that was the most important, assuming both oils have the same specs.

 

[rjacket]

Originally Posted By: MajorCavalry
No experts that can explain this?

I had thought that it was the high temp viscosity that was the most important, assuming both oils have the same specs.


Let me give a hypothesis.

The 3.7 engine is older than the 3.5. They tested the 3.7 with 5w20. When they developed the 3.5, 0w20 became available and they tested it with that.

It will probably be ok, they just haven't gotten round to testing it / stating it is ok in the paperwork.

Kind of like Ford engines which ran on 5w30 until 5w20's became good enough to consider, then they tested them, then they backspec'd the engines. I believe Lexus did something similar with oil weight and OCI.