IMO, the 1.4T won't hold up to as much abuse as the GM 3800 could. But properly maintained, the engine itself should be good for 200k+ miles. The turbocharger is my only concern about this engine making it to 200k without any major repair.
The key word is "with proper maintenance."
The GM L67 and L36 required significant work to remain reliable. Regarding the L36, we had a faulty upper intake plenum that required replacing due to the EGR valve causing the plastic to crack around the coolant passages, potentially flooding the engine with coolant, in addition to lower intake manifold gaskets that were in terrible shape well before 200k miles. We had the coolant elbows that liked to crack, an oil pan gasket that was notorious for leaks and required a removal of the subframe to remedy, and very common idler pulley bearing failures. The supercharger added another maintenance item that was very often ignored.
I suspect that, like the 3800 series, the 1.4T will be just as reliable once known issues are remedied
. The key to this is proper maintenance and preventive maintenance. It goes without saying that good lubricants that are changed according to their usable service life will go a long way. Going 10,000 miles on DEXOS1 oil in city driving is a sure way to reduce the life of your engine just as going over 90,000 miles on transmission fluid for either engine is sure to reduce the life of your transmission.
The turbocharger is lubricated through the use of scroll bearings and cooled by both the oil and the turbo. So long as a lubricant is used that withstands the heat produced by that turbocharger without shearing, oxidizing, or becoming acidic, the turbo should theoretically last the life of the engine. This would also assume that the antifreeze is maintained to its service life of 150,000 miles or 5 years, whichever comes first. The cooler you can keep the turbo and the better you can keep it lubricated, the longer it will last you.
Mazdaspeed3 owners learned this lesson the hard way when Mazda insisted that they use conventional oil. Turbo failures between 30k and 60k miles were not uncommon. Subaru WRX/STI motors suffered the same fate, only those turbos ran so hot that they oxidized the heck out of the oil, which then caused it to sludge and clog the oil mesh screen inside the oiling system, thus starving the turbo of oil. With turbocharged applications, oil is absolutely critical to the turbo's service life.
That being said, there was one instance of a turbo failure reported where the compressor housing literally cracked. Unfortunately, the best lubrication won't save you from that, but excellent cooling will help prevent it. This is not intended as an AMSOIL plug, but this is one reason why I run the Dominator Coolant Boost
, which increases surface tension between the metal and the antifreeze to provide better heat transfer. In theory
, this should keep the turbo cooler, which in theory should extend its life.