Greetings

[anchorman]

Fully synthetic is technically better than semi synthetic but it can cling to the cylinder walls well enough to raise consumption. Not usually a problem but keep an eye on it weekly for a while after changing just until you get a feel for it.

That's interesting, Don. I know that fully synthetic isn't good when "running in" because it prevents the bits bedding in but I always reckoned it was best for long-term use after that. Our '02 VVTi has been run on full synth since new. It has 70K + on now and has never used a drop of oil - ever. Having said that, I used to always get the oil & filter changed every 6K miles or 6 months up until about 30K irrespective of mileage. The '54 reg has 38K on and FTSH on full synth and, so far, doesn't use any oil.

Honest John's review of the 4.2 lists increasing oil consumption after 40K miles as one of the few faults but so far (touching wood furiously) ours have been fine.

Some engines that don't have an underlying problem and are fully bedded in will not use oil of any kind (between services).