Auto FE - It's all about driving style

[dosco]

Originally Posted by theholycow

Oh, no HS physics class is necessary to know that it takes more work to move a load uphill than downhill.

Sorry, wasn't trying to be a prick or anything, just never know about who knows what.

However, regardless of when you pulse and when you glide, it still takes the same amount of energy to move the same weight over the same hills.

Pulsing downhill means a larger difference between your high and low speeds. Your high speed will be higher, and common knowledge is that waste from aerodynamic drag is not merely equal to the increase in speed but is exponential or some such. So, that, in addition to BSFC and pumping loss minimization (which in an automatic are difficult at best), are why I would assume that uphill pulse and downhill glide are the best.

However increasing speed (say pulsing from 60 to 70 mph) when traveling uphill requires more energy than maintaining a constant speed uphill - correct? So why does it make sense to pulse uphill if the car has to expend more energy (i.e. use more fuel) to accelerate uphill?


Pulsing from 60 to 70 mph downhill would require less energy due to the conversion of potential to kinetic energy - correct?

Furthermore, the energy wasted to aerodynamic drag is going to be the same regardless of going uphill or downhill, right? So why not take advantage of the free work from gravity to offset the energy wasted to drag, rather than use more fuel on the uphill to work against both the incline and aero drag?