Water cooled exhaust manifold = 20% fuel economy gain

[cRiPpLe_rOoStEr]

Originally Posted by litesong

The rising European death rates due to increasing diesel particulates & emissions were telling the true stories.

It's becoming an issue with gassers too, because of direct-injection becoming widespread on them, to the point that a particulate filter becomes mandatory for gasser versions of certain models too. The current-generation Mercedes-Benz A-Class is available in my country only as a gasser, but it's now fitted with particulate filter.

[MeteorGray]

I wonder if direct-injection gas engines are more efficient enough to justify the addition of particulate filters? Otherwise, why not just go back to indirect injection gas models.

Or, perhaps the direct-injection gas engines don't produce enough particulates to make adding a particulate filter the expensive and disruptive mess that diesels are having to contend with nowadays.

[cRiPpLe_rOoStEr]

Originally Posted by MeteorGray

I wonder if direct-injection gas engines are more efficient enough to justify the addition of particulate filters? Otherwise, why not just go back to indirect injection gas models.

It's not just about direct injection, it has also something to do with enabling a leaner burn on higher-compression engines.

Or, perhaps the direct-injection gas engines don't produce enough particulates to make adding a particulate filter the expensive and disruptive mess that diesels are having to contend with nowadays.

Since the fuel for a gasser or a flexfuel is more volatile, the particulate matter emission might remain less troublesome. What might also influence is the fact that gassers might resort more frequently than Diesel engines to some fuel enrichment in order to decrease the NOx emissions, at the cost of higher PM levels...

[litesong]

Originally Posted by cRiPpLe_rOoStEr

It's becoming an issue with gassers too, because of direct-injection.....Mercedes-Benz A-Class is available in my country only as a gasser, but it's now fitted with particulate filter.

Ah, rich Mercedes saw that criminal air pollution conduct by VW didn't put any VW officials in jail. So other methods of polluting the air are..... "good to go".

I've heard that burning 100% ethanol-free gasoline (E0), instead of 10% ethanol blends, helps reduce deposits in DI engines. Might the use of E0, instead of 10% ethanol blends, also reduce particulate air pollution?

[cRiPpLe_rOoStEr]

Originally Posted by litesong

I've heard that burning 100% ethanol-free gasoline (E0), instead of 10% ethanol blends, helps reduce deposits in DI engines.

I'm not so sure about it, but it doesn't seem so likely.

Might the use of E0, instead of 10% ethanol blends, also reduce particulate air pollution?

I'd also not hold my breath for that. Even though ethanol may be harder to fully vaporize on port-injection engines, with DI it has been possible to avoid pre-heating of the fuel as a cold-starting aid. Trimming the AFR a little leaner at the cold starts might help to decrease the PM emissions in a worst-case scenario.