Quick Oil change question

I went through something like this awhile back when all the stores were closed on a Sunday and all I could get was a mix/match of oils.

Found the following Mobil Oil website, which basicially says, if I understand it correctly, is that it is fine, but don't do it because you should only buy our Mobil 1. LOL!!!
Will Mixing Synthetic with Conventional Oil Cause a Gel to Form?

 

Since you are currently using a blend, you could top off the last 1/2 quart with either mineral oil (aka dino) or with synthetic oil. Further, I question the assertion that you can't go back to a quality mineral oil once synthetic oil has been used.

 

You can do this with no problem. Also, you should be aware that there is absolutely no problem going from synthetic to dino or vice versa. It has been this way for many years. Also there is no problem mixing them if you need to add a bit.

 

What does the dipstick read right now? I'll bet a nickel that the level is *not* a half-quart under the ADD mark.

 

Seriously: *check the dipstick* before you add any more oil. It might already be nearly to the FULL mark.

 

The first synthetic oils that came out about 15-20 years ago were not compatible with "normal" oil. You had to clean out the old oil before adding the synthetic. I know from experience that oil would catalyze into plastic if mixed. Modern synthetics are fully mixable. Especially "blend" synthetic oils, which come mixed.

But DO check the dipstick, and add enough to -just- bring it to the "full" mark. Even if it's down 1/4" it will be just fine. In fact, it will be fine even down 1/2". It's just that the higher the volume of oil, the more diluted the contaminants will be.

Unless you're racing and applying high side loads in corners, in which case you want as much oil in there as possible so you don't get the pickup out of it from sloshing. But I don't think -I- could get that high a side G in the Prius, much less from acceleration.