Thanks for the reply.
Originally Posted by foama
There is a common problem in the US where the dealers regularly put 4-5 quarts of oil into the engines, when it requires much less. This could be causing excess aeration / foaming which could be either going through the now over-saturated PCV valve, or through some kind of a seal leak due to the oil overfill (or just bad seals from the start) or even both. That excess oil could easily causes carbon build-up problems.
This could have been the cause for that fleet, maybe you as well, but I'm not sure if you changed your own oil.
View my fuel log 2015 Mirage ES 1.2 automatic: 51.7 mpg (US) ... 22.0 km/L ... 4.6 L/100 km ... 62.0 mpg (Imp)