2006 pontiac grand prix 3.8

[PhillyJoe]

Originally Posted By: vinsonclarkjeep
Mixing Mobil 1 high milage and Mobil 1 Extended Performance together won't hurt anything?


You can mix any oil with any other oil and certainly you can mix within the same brand. The high mileage oil has sealers that might just help. The advertising will say "for cars over 75,000 miles" but there is no set rule.

 

[vinsonclarkjeep]

What about mixing 1 quart 5w-40 HM and 3.5 quarts Mobil 1 Extended Performance 5w30? Would this hurt anything? How many of you guys blend oil?

 

[A_Harman]

Most, if not all, participants on BITOG blend oils, but we all recognize that when you blend, you are weakening the unique characteristics of both oils. If you want more of a significant benefit of the High Mileage oil, you should blend it at higher than 22%. The first time I tried Mobil 1 High Mileage, I blended it 50% with regular M1. Then on the next oil change, I went 100% High Mileage. It worked for me, but I don't think it would cause a problem to go 100% the first time.

 

[vinsonclarkjeep]

What about blending 50/50 every change? Would a 5000 mile OCI be good with this blend? And also what weight oil is best for the gm 3.8 its out of warranty so that's not s factor.

 

[A_Harman]

If I'm remembering correctly, GM never specified anything but 10w30 for the 3.8. Since you're in Mississippi, it doesn't seem like you would need a 5w or 0w30. Mobil 1 in a 2006 GM car will easily go 5000 miles. You should follow the Oil Life Monitor and change oil when it says. For Example: the OLM in my Camaro requires 7500 mile oil changes under normal street driving conditions.

 

[PhillyJoe]

Pretty sure GM says 5w30. Check your manual or oil fill cap.
The OLM is roughly 10,000 miles; mine seems to go down 1% for every 100 miles I drive.