Opinions on mixing conventional and synthetic oil

[koda2000]

I use Mobil 1 Extended Performance in all my vehicles. I change the filters at around 7,000 miles and I change the oil roughly once a year (typically under 10,000 mile per year). Normally, if I need to add oil I add the same kind of oil, however in a pinch would it hurt to add a quart of conventional oil?

 

[swshawaii]

Surprising to see this question coming from you koda2000. Actually, I'm SHOCKED and LMAO!

I'm sure the same applies to ALL brands of oil. You now have a "synthetic blend" or a "semi synthetic".

Is it okay to mix conventional motor oil with Mobil 1?

Yes. Mobil 1 is fully compatible with conventional motor oils, semi-synthetic motor oils, and other synthetic motor oils, should it be necessary to mix them. But the superior performance of Mobil 1 will be reduced by diluting it.

http://www.mobiloil.com/USA-English/MotorOil/Oils/Mobil_1_FAQs.aspx#FAQs2

 

[koda2000]

i never mix oils, but my son-in-law needed a quart of oil and couldn't find Mobil 1 EP. i figured it would be okay to put in whatever he could find, but it got me wondering.

 

[jremington59]

I've mixed oils a lot. I use synthetic, but if it's near oil change time I'll add some reg oil. That's what a synthetic blend is anyways.

 

[Flash]

Definitely ok to to mix synth and dino.
It's better to use synth if there is extended time between oil changes because it doesn't oxidise.

 

[my98nnj]

i but it got me wondering.

Stop wondering...

 

[koda2000]

that makes perfect sense and it would typically be around the time the oil is near changing. thanks for putting my mind at rest about it, it's an OCD thing. jr59 - i know you understand.

 

[pcam13]

Mixing same grade is fine. Mixed oils since I got my first truck.

 

[lobo411]

My attitude is this is a truck with a truck engine. Not picky at all. Maybe if this was an airplane engine or a Ferrari, but it's a glorified Ranger!

 

[jremington59]

that makes perfect sense and it would typically be around the time the oil is near changing. thanks for putting my mind at rest about it, it's an OCD thing. jr59 - i know you understand.

I understand, lol.....

 

[DjDom]

I've mixed everything in there.. from synthetics with dinos to 10w30 with 5w20. My engine takes it all.

 

[SoNic67]

My engine doesn't like any dino oils. It takes only the "best": Mobile1 0W-40 with 1qt of Lucas Synthetic . Or 5W-50.
Anything else and, with hot engine, at idle rpm, oil pressure drops at 5psi and needle starts to bounce like crazy.