Can add pack selection influence consumption?

[fdcg27]

Is it possible that there could be a difference in consumption between oils with a sodium heavy add pack, and those that don't use sodium?
I'm asking because the old Impreza seems to have considerably higher oil consumption using Castrol GTX HM that it did using PP.
I've even tried topping up with some GTX 20W-50 I have laying around, a leftover from an old Mercedes we used to have, which I had dedicated to the lawnmowers, and relatively higher consumption continues.
I doubt that the PCV system suddenly ceased to function with the change to Castrol.
The car's next fill will be Defy, so we'll see what happens.

 

[skellyman]

Additive packs can have a big influence on oil usage !

 

[KCJeep]

Sometimes a vehicle will exhibit consumption when you switch and then settle down after a bit. Surprised it is drinking Castrol High Mileage though, that is mighty thick stuff for grade!

 

[fdcg27]

I was surprised too.
The only reason the car got this fill was that it was on clearance at Meijer for the ungodly price of $1.49/gallon.
Meijer clearanced all of their gallon jugs starting last summer, and this one just happened to have sat long enough to reach almost free status.
I have never been a big fan of Castrol oil in general, other than GC.

 

[mechtech2]

I also find it odd that consumption went up with a thicker oil.
Viscosity is #1 and #2 for oil leaks and burning.

I don't know for sure of any additives that would attenuate or increase oil use, but hopefully some of the more well versed members do.

 

[fdcg27]

Unless the PCV valve suddenly and coincidentally went south?
I'll install a new one and see what happens, as well as inspecting the hoses to see that they're clear.