Mixing SM, SL, dino, synth, visc & brands question

[Seth]

Can I
1. mix 1.5 quarts of M1 SL 5W30 with 1 quart of M1 SM 5w30 and 2 quarts of dino Tech2000 SM 5w30
2. and stick it in my new mitsu specd for 5w20?

Currently have GTX 5w20 SM in crankcase. A little of that is left over which I will mix with whatever Mobil 1 5w20 SM left over. I will use this after I get rid of my 5w30 unused oil.

I want to get rid of unused old oil (both 5w30 and 5w20) so that next time onwards, I will stick with one brand one viscosity...

 

[hominid7]

It will not likely hurt anything, but if it were *my* brand new car, i would certainly be sticking with what the owners manual recommends and not mixing oils.

 

[Seth]

hominid, Short OCI of 3000 km should not affect it right? I dont plan on going the usual long term on this mixed stuff... btw, M1 label says that it is "compatible with conventional oil".

 

[hominid7]

I don't think you'll hurt anything, it's just that when mixing conventional and synthetic, don't think of it as "improving" the conventional. It will likely default to the lowest common factor, that being the conventional oil.

3000km should not be a big worry though. The SL Mobil 1 is plenty good, but long term use (ie 100,000 miles) of use may shorten the life of your emission components, assuming your car was orig spec'd for an SM oil.

All motor oils are generally compatible with other oils. However Mobil 1 uses one formula of additives to combate wear and control deposits, which may be different from another oil. So you end up with a mixture of additives of varying percentages and types. The base oils, i have much less concern about them being mixed. For 1 or 2 oil change intervals your chance of doing any long term harm however are very minimal in my unscientific opinion.

 

[Merkava_4]

ADDITIVE CLASH!

just kidding. . .