I have the opportunity to buy full syn oils by different manufacturers and slightly different
weights (5-20 and 0-20). Would mixing them pose any issues of consequence in an
LS460?

 

It should not be a problem however not knowing about the additive formulation for extended use I would change the oil at 5k miles.

 

I think most would tell you it's not ideal...additive packages might not mesh or may counteract wit eachother, but personally I think it'd be fine. And like Devh said, just don't let it go for an extended drain.

Right now I'm coming up on another oil change...been running Mobil 1 for about 7500 miles. I got a very good price on some Napa synthetic (basically free), so I'm going to use it - I've used it before and it was fine - but I'm only going to let it run for 5,000 miles. Napa synthetic is essentially Valvoline and the additive package is not exactly robust.

 

Certainly not optimum. Optimum would be an extended drain for less wear and less work.
If you factor that into the equation then the only savings that would be gained if any would be if you got the discounted oil at $2 a quart.

 

I'm no expert, but I agree it should work. I just don't think you will full benefit from any oil reaching its full potential. I think it would create an average oil. As long as all oils are a major brand. Not any discount oils

 

Thanks for the confirmation. I never let my oil get to 5k, that way I avoid the emission test and its charge. I have two cars, so I can manage to keep both under 5k a yr..

 

I wouldn't hesitate for a minute. Especially with a 5k mile OCI