Only early DI engines have issues with coking, the later GM HFV6 with DI and Ford's own Focus 2.0DI
as well as all of the later Ecoboost engines have had no real issue with it. Think about it if coking had been
the major issue some think, it would be making headline news but guess what...nada zippo. It's a dead issue.
Mazda's own work on GDI and GDIT has shown that a lot of improvement is possible with tailoring DI's combustion
traits over those of simple port injection, it's not the 1990s and 200s anymore, many manufacturers are realizing
that the emissions profile and control afforded by DI is far superior to just squirting fuel into a manifold.
The cost of an exhaust particle filter for GDI and GDT is around $50 when first discussed by the EU ten years ago
and with wider spread applications thse days, I'd expect the cost now would be even lower and simply added
to the service schedule.
Ford is not going to drop Ecoboost, they see how it has grabbed the public's imagination and now, over 70%
of F150 buyers have switched to ecoboost, pFI V8s are being left behind, GM's 5.3 and 6.2 V8s are now DI
to stay in the game, without it they csimply can't deliver the necessary power and emissions profile.
Edited by jpd80, 03 December 2016 - 04:45 PM.