superdave said:
I read in one of my Chrysler magazines that they were originally going to put a light in the dash telling you when it the car was in four cylinder mode, but it goes in and out so often the proposed light was simply an annoying flashing light.
Yes, this is true. There's no delay in the logic, so the system cycles on/off continuously.
The following is from
here:
works between 1000 and 3000 rpm, or about 15 to 80 mph.
Threshold is if the vehicle can maintain it's course utilizing less than 95% of torque available from only 4 cylinders, it will then cut 1, 4, 6, and 7. Changeover occurs in approx 50 to 80 milliseconds. There is no delay reaction built into the logic, it will cut the cylinders as soon as that threshold is attained.
The valve lifters are dissabled, and one burned charge is retained withing the cylinder(s). The charge acts as an "air spring", allowing the engine to "lose less" energy than just cutting a fuel injector and flowing air through the combustion chamber. This one charge is cycled out/new one in after a certain period of time due to gas blow-by the piston rings reducing efficiency. Once temperatures stabilize (few seconds or so, environment dependent) the cycle repeats itself.
The system works continuously for a maximum of six minutes, after which the four cylinders come back on-line, to stabilize cylinder temperatures, and maintain combustion, emissions, and mechanical efficiency.