in a nutshell: computer control of ignition COULD either minimize fuel consumption or NOx pollution
At part throttle,
computer control of spark allows for more tailoring of the advance for things other than vacuum... such as
intake air temperature,
coolant temperature
quickness of throttle blade opening
how rapidly rpm is increasing,
etc
The factory '96-2001 Dodge Magnum OBD-II PCM reads all those extra factors before setting the ignition advance,
whereas a conventional distributor just sets it by rpm and vacuum.
these additional inputs are not going to give you any more horsepower,
because when you are at part throttle you can always get more power by opening the throttle more
nearly all the benefit will be to fuel economy from a more optimum ignition timing advance.
i would guess that the increase in MPG would be more than 1 but less than 3 in city-style driving
in terms of pollution,
the gases grouped together and called NOx are VERY sensitive to ignition timing.
Computer control of the timing may be required to pass the strictest emissions.
Unfortunately, the changes to ignition advance that lower NOx nearly always hurt fuel economy. Retarding timing from optimum reduces NOx gas emissions... it can cut them to a third of the NOx that would be produced at 'best torque' timing while suffering about a 15% loss in fuel economy
You seldom here a politician admit this... that the stuff they require to decrease NOx gases are increasing both CO2 gas and costing all drivers extra $
The extra $ currently being spent on more fuel to reduce NOx could have been spent on reducing water pollution,
or just increasing knowledge through education, since so many worldwide are technically uneducated.
I have wondered whether just teaching poor women outside the USA how to build cooking fires with less smoke would not be a much better use of $,
or teaching men overseas how to adjust old engines for fuel and spark.... but that is wondering off subject
