3.1l w/150k on the clock syn oil chooses

[JR]

i just got a 3.1l with 151k on it
i have put like a thousand on it no oil leaks or burn
i was thinking bout dumping syn oil in it
i was thinking about staying with a Xw-30
i was thinking bout shell t5 10w30
m1 0w-30, 5/10w-30, 5w30 t&suv, 5w-40tdt, 0w-40
or m1 hm oil 5/10w-30, 10w-40
which of these would be best?
i was thinking the 0w30 but are any of the others better?
and what would you requemend for a oci
i was thinking 10k but not sure

 

[pitzel]

GM 3.1? I've done 38k miles/5 years on Esso XD-3 0w30 oil in the GM 3.1L V6. No sludge; only dumped the oil because the engine developed a coolant leak and had to be torn down to replace some gaskets. Would have run the oil much longer.

 

[pbm]

Pitzel: Are you saying you did a 38K/5year OCI on the same oil? How much did you add?

I just dumped full PAO synthetic Pennzoil Performax from my 3.1 at 6200 miles (7 months of winter) because the GM oil life monitor went off at 5800 miles. The OCI before that was the same oil and approximately the same OCI.
I didn't have the ba**s to go to 8K and you went to 38K. Amazing.

Did you do a UOA?

I have some ESSO XD-3 0W30 synthetic and plan to use it (maybe) next winter. I used to be a 3K OCI guy so going double that is adventureous for me. I guess I get a little nervous when the Oil Life monitor light goes on.

 

[The_Eric]

If it's a GM 3.1, feel free to run whatever. Ours is at 235K. The first 90k was Mobil/Castrol synthetic (original owner) and from there till now, it's almost been entirely parts store labeled 5w30 dino oil and Wix filters. Doesn't burn any oil, just leaks it.

 

[JR]

do any of you guys say run 10k and for get it
or is m1 ep good enough for 15k

 

[Bill in Utah]

Originally Posted By: JR
do any of you guys say run 10k and for get it
or is m1 ep good enough for 15k


Any one who says yes is just GUESSING with YOUR engine.

You have not given us enough data to make any type of a ACCURATE guess.

Any comment is just a guess until you work up to the OCI with trending UOAs...

Personally No would be my answer to both of your questions.

Take care, Bill

 

[ThirdeYe]

My mom's 3.1 showed great results with regular Castrol GTX at 5,000 mile intervals (could go further). You could probably use M1 0w30 at 7,500 mile intervals year round, provided it's not all short trip driving.