It seems like the trend is to use 4-cyl turbos to replace inline-6 for the new Bimmers across the board. Some people claimed that most manufacturers had to meet emission requirements so they reduced the engine displacement to achieve that. Well, that is not convincing because it's clear the Porsche 718 Spyder is new and it's 4.0L naturally aspirated. How did Porsche get pass that hurdle if emission has to do with engine displacement. Direct Injection is another sore point where the PCV poops onto where the intake valves: thereby, stirring up the idea about eating where you poop. Sooner or later, the intake valves are all going to get choked up. Anyone know how BMW is solving these problems?
For the U.S., I think direct-injection turbo motors are the only ones we have now. I'd figure the only way carbon buildup and eventual need for cleaning via walnut-shell blasting would become much of a concern for BMW corporate is if it became a widespread issue (& thus substantial cost) for in-warranty vehicles, or possibly if BMW found it to be seriously denting repeat sales & new-buyer purchasing decisions. I don't know what percentage of sales are CPO vehicles, that presumably would be the one customer group that would stand the highest chance of having to deal with carbon-buildup issues that could end up being a material cost to BMW, under the CPO warranty.
Well, small turbos is an industry trend; even the conservative Honda has dropped their V6 Accords for 4 cyl turbos. I expect BMW to lead rather than follow the herd. Whether the choked intake valves will become a problem or not will depend on highly broadcast cases. But, I think BMW is relying on the the new demographics that do not keep their cars more than 4 years. That means as long as their cars can last more than 4 years, new sales will keep the CEO look good and that's all that counts. But, sadly, the long term effect is that it will tarnish the image and the brand and leave it with an irreparable damage.
