Oil consumption on older car

I would suggest that you make sure the flame-trap is cleaned at least once a year (every 10,000 miles), to keep crankcase pressure down - which will push oil past the seals.

If you're not in a warm climate, don't use a higher viscosity oil. And what's the point of wasting money on "semi-synthetic" oil (is this Valvoline Durablend)? Might as well as go with regular dino oil.

AC

I'll bet that virtually all of the oil is going out that main seal. What often happens is it will leak much more on the highway than at low speeds near home, so you only see a few drops under the car. The advice about the flame trap is solid.

The blended oil if often around 5% why even bother, use the real synthetic oil ,avoid imitations .so I wont use castrol, got my drift .

I agree, and my point was that if the engine has gone 200,000+ miles on what is basically dino oil (syn. blend), why not just save money and stick with dino .....

Switching to synthetic after so many miles may get oil past the valve seals etc.

AC

Thanks everyone for all the helpful advice. One question - does "semi-synthetic" oil like (Castrol GTX Magnatec in the UK) confer no benefits over regular mineral oil at all? In which case, are there any benefits to the engine in using "fully-synthetic" oil such as Mobile-One, which is very expensive?