every car is different. On my Subaru with a modified drive by wire, fuel map and ignition timing map, keeping loads and RPMs low helps a lot (variable valve lift in my Subaru avoids pumping losses traditionally associated with conventional SI engines). So if i wanna be efficient I accelerate at 60% load at around 1700rpm up a hill then coast down. This can cause my speed to bleed depending o grade and length of the hill therefore I might downshift to get back to speed then start the bleeding process all over. I usually go DFCO on the way down the hill (my car enables DFCO above 1100rpm which means I will be using no fuel down the hill no matter what gear i'm in, unless i'm going slower than 25mph which is rare). RPM or engine load spikes ruin my daily trip mileages as my car goes open loop above 85% relative engine load and/or 3200rpm. Also for me high engine load results in significantly lower ignition timing vs moderate loads, means lower volumetric efficiency. It all DEPENDS on the car. Master feathering the throttle and you are good, kinda like having an egg shell between your foot and pedal and you don't want to crack the shell.
On my honda I just drive the car hard and the outcome is not so different from babying it.
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Last edited by ever_green; 01-07-2014 at 11:26 PM..
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