Oil Change - same weight difference brands

[davefisher]

I switched to sythetic about 2 years ago and usually use Mobil1 5-30, but last time I picked up some Valvoline synthetic, as it was on sale. This change I'm about to do next week (70k), I have 1.5 qts of the Valvoline syn-power left, and now Advance Auto has a sale on the Castrol Syntec (which I run in my VW, 5-40, and love it!)

Question: Any problems mixing 5qts of Castrol with 1.5qts of Valvoline... identical weight (5-30), both full synthetic.

Ideas, thoughts? Thanks!!

 

[kn38ms]

All is well. No problems as long its the same weight

 

[davefisher]

Good to know. Thanks. I didn't see any problem with it myself, but wanted to run it by just in case.

I figured as long as it's the same weight and both full syn, as opposed to some syn and some traditional... I would be okay... of course, I also hear once you go to full synthetic, you shouldn't switch back to dino oil.

Thanks for the good word.

 

[wolfgang]

I can't see why even mixing weights would matter - so you end up with 7W35. New lubricant is better than old lubricant any day. I've opened differnt jugs of oil same brand and weight and notice a difference in color so guess it either came from different refinery or a different run - not like wall paper where it shows.

I've heard the "you can't go back" but suspect its a marketing ploy. Have read that there is no problem mixing full synthetic with the synthetic blend. Where's Myth Busters when ya need them?

 

[wolfgang]

I can't see why even mixing weights would matter - so you end up with 7W35. New lubricant is better than old lubricant any day. I've opened different jugs of oil ()same brand and weight and notice a difference in color so guess it either came from different refinery or a different run - not like wall paper where it shows.

I've heard the "you can't go back" but suspect its a marketing ploy. Have read that there is no problem mixing full synthetic with the synthetic blend. Where's Myth Busters when ya need them?