Originally Posted By: wemay
Bitog consensus from those who post often is that GDi is a step back, not forward. I disagree but the sentiment is there.
Noonooonooo...especially if I'm included in the conversation.
GDI is a step forward...from the Mercedes, Messerschmidt it was superior in a lot of ways
https://en.wikipedia.org/wiki/Mercedes-Benz_300_SL
Texaco stratified charge direct injection of the 80s was cutting edge.
GDI stratified charge was supposed to keep the fuel away from the cylinder oil film, reducing HC and CO emissions, and deposits...was tested with O ring top piston rings in the early development phases to show the gains possible.
We saw on BITOG quite some time ago as Audis were being delivered to the US market with GDI that wa=hatever it was that they needed to do to get them US compliant, plus US fuels/lubricants were leading to fuel dilution, wear, deposits etc. that (apparently) weren't prevalent in their "native" environment.
Huge discussions, Terry Dyson, Envirolubes, Audi patents for engine oils that reduced intake and piston deposits.
Now we've got GDI, we've got fuel dilution, we've got port deposits, we've got the things that were being discussed with the Audies all those years ago.
GDI isn't bad, a step backwards, or inherently a problem
Diesel isn't bad, a step backward, or inherently a problem.
But there's a(multiple) problem(s) with it in it's current application in some(a) market(s) which have other, multiple competing goalposts.
e.g. Dexos 2 specced for some engines in Oz, warranty voided if use Dexos 1, where other markets (CAFE) it's Dexos 1, and take what you get.