Mixing engine oils

[Chimjunkie]

Should I be concerned if my engine running Silkoline Pro S is topped up with 1.5L of Mobil Synth S ??

Cheers, jon.

[Slacey]

According to Opie Oils, not at all. I usually top up with a different brand (whatever I have to hand at the time, usually the Silkoline you mentioned) with no problems.

[Andy JB]

As long as the oil viscocity is the same (eg 10w 40) - brands don't really matter

[shropshire lad]

If the viscosities are different is the end result a compromise on characteristics or something more risky and to be avoided.

[Slacey]

I've mixed viscosities too without any problems, but in these cases always topped up with a thicker oil than the bulk that's already in there.

[BryanWilton]

I thought you could mix any fully synthetic oils together?
Thought it was ok to mix any fully synthetic with any semi-synthetic as well....

As long as you don't mix either with regular mineral oil

[Slacey]

BryanWilton said:

I thought you could mix any fully synthetic oils together?
Thought it was ok to mix any fully synthetic with any semi-synthetic as well....

As long as you don't mix either with regular mineral oil

Sounds about right to me.