Optimal gas pedal/HSI postions in highway light load scenario

I do something similar with trying to keep the accelerator in certain sections of the gas bar. However, once I'm up to speed on the declines, I'll try to "glide" instead of building up more speed. My logic is that the wind resistance will decrease my overall mpgs as I increase my speed beyond 60 mph, so I try to use gravity to take me to 60 mph.

My dilema is when I'm going down a decent grade and my gliding will take me to 65 mph+. Do I glide to 65 mph and continue to glide down to 60 mph or glide to 60 mph and hold 60 mph by removing my foot from the gas pedal to maintain 60 mph and add a little back to the battery. I don't know which is the best for efficiency.

 

It is more fuel efficient to allow the Prius go faster on the downhill on its own momentum than to slow it down with the regen brakes. Aerodynamic Drag loss is not as bad as the energy loss caused by converting the mechanical energy of the wheel into electricity. If the Prius going over 65 mph - safety should be the primary factor in limitig speed and using the brakes ; the second factor would be avoiding getting a speeding citation/violation.

 

@ thread starter

Thank you.

good tricks in details, for tyre inflation, how much did you inflate?

 

You'll refine your technique as you learn where you can gain speed and maintain speed on the highway.

The HSI is a good guide for pulse and glide; however, the pulse zone (3/4 to 4/4 of the HSI) is not the most efficient zone for maintaining speed; it is the most efficient zone for increasing speed. (I've generalised a bit.)

At 55mph (88km/h) the best place might be just over the 1/2 mark of the HSI. The only way to tell is to use a Scangauge, Garmin ecorouteHD, etc. that shows you the instantaneous mpg, ignition timing, etc. If IGN is right, you could almost maintain 55 mph with iMPG of 90 mpg for short periods.
For example, I look at the instantaneous fuel consumption and if I'm in the range 2.0-3.5l/100km (120 - 68 mpg) and travelling at 80-110km/h (50-70 mph) then the IGN is probably right. You might be almost anywhere on the HSI when that's happening. You may need a pulse to get you back to speed.

If you can avoid cruise control (CC), do so. On most cars using the accelerator supplements the CC, so you can use it before a climb to make up some speed. By contrast the accelerator seems to take over CC on the Prius, so the pre-climb acceleration works, but the CC doesn't take over while the accelerator is depressed.
Also, CC will apply regen on downhills, which is nice when you really want to keep to the speed limit. However, you often want to build speed for the next climb.

Assuming that you want to use CC, you may want to select PWR mode before a steep climb. In PWR mode CC tries to maintain the set speed, dropping slightly before accelerating. HSI may enter the PWR zone doing this.
In ECO mode, the speed can drop 10km/h (6mph) below the set speed, at which time all available power is dumped to the road to restore normal service, as the PWR zone of the HSI glows red hot. I'd suggest that CC with PWR mode left to its own devices on a steep hill is better than CC with ECO mode left to its own devices. If you need to get up the slope at the speed limit and on CC, use PWR mode. (Switch to ECO mode as you level out or descend.)
Note: This is not the most efficient way up the mountain, it is just quick and convenient.

And not using CC is better than both.