
Naturally Aspirated
Posts: 16
Joined: Fri May 10, 2013 3:20 am
Location: United Kingdom
Cars: Ford Focus RS 2.5L 305HP
1982 Corvette Stingray 5.7L Cross-fire injection
Direct Injection Emissions should be higher?
Just wanted to say that the emissions number reducing when using direct injection compared to port injection is wrong. The fact is hydrocarbon emissions are generally higher and particulate emissions are extremely high, much higher than that of a modern DPF diesel, in a direct injection gasoline engine. NOx emissions are also increased if a stratified fueling stratagy is used. When adding a turbocharger the emissions are made further worse as the turbo takes heat out of the exhaust, resulting in longer catalyst light off and more emission slippage when driving cold as well as added NOx at high load operation.
Here are some official emission results from the UK government website comparing an NA 1.6 to a smaller 1.0 GTDI engine of the same output in the same vehcile:
(g/km)
CO - 1.6: 0.342 GTDI: 0.347 (Slightly higher)
HC - 1.6: 0.057 GTDI: 0.064 (Over 10% higher)
NOx -1.6: 0.051 GDTI: 0.039 (Lower as this particular GTDI engine does not use stratified injection)
No soot / particualte information was given, but you would find the GTDI would have a huge increase over the 1.6.
Of course the CO2 is lower with the GTDI engine, but CO2 is directly proportional to fuel economy (with small variations depending on fuel quality and feedgas CO concentration) so should be kept separate to the 'emissions' measurement in the game in my opinion.
Correcting this would make the game a lot more realistic and really show the trade off between fuel economy/(co2) and the other exhaust emissions which are actually poisonous, damaging to the environment and carcinogenic.