Using leftovers

[ProfPS]

I have a neighbor who is planning to use his leftover 5w30 oil in a 2007 V6 Pontiac. The mix will be 2 qts of Valv AC (SL), 1 qt Pennzoil conventional (SL), 1 qt Chevron Sup (SM), and 3/4 qt of QS (SM).

Do you think he should do it? If so, should he run it in the summer or fall, and what OCI?

Thanks.

 

[Bill in Utah]

My only problem would be if the car asks for API SM...

If it states in the manual or on the oil cap SL/SM I'd take it to 5k or 6 mo.

Take care, bill

 

[Eddie]

I agree with Bill. Check the oil requirement in the owners manual as I think SM is specified. If the owner insists on using the SL oil when SM is required then cut the OCI to 3,000 miles.

 

[ProfPS]

I'm thinking of suggesting that he mix them together in a 5 qt jug and use it for top-off oil. What do you think?

 

[Gary Allan]

If it's not going to take him 5 years to use it up, sure. I wouldn't worry about it either way. I'd like to see the common passenger car engine that realized anything substantial (as in measurable) over one, properly spanned, OCI.