After reading multiple threads about P&G, I am a bit confused on the most fuel efficient way to pulse. I've gotten the glide part down. I think most of us have seen the image of pulse and glide where the pulse zone is the upper half of the ICE band. However, some threads suggest that the most fuel efficient way to pulse is to slowly get up to speed by pulsing only a bit past the halfway point. I don't have Scangauge so I can't tell what RPMs the ICE is running so can somehow clarify where the best pulse should be done? I read something about how pulsing at the upper half of the ICE region will produce more power than the ICE needs and will be sent to the batteries, wasting gas. But conversely wouldn't slowly pulsing require the ICE to be on longer, also using more gas? Thanks!
It kinda depends on how far you think you can glide. If you pulse with a 20 mpg average then you will have to glide further than if you pulsed with a 30mpg average to acheive say 100mpg. Most say you should keep rpm around 2100-2200. Or you can go by the guideline of keeping mpg at least half your mph. Have you watched this video? http://priuschat.com/forums/gen-iii...max-mpg-driving-techniques-youtube-video.html
The best way to pulse is at about 75-100% of the Eco bar, or as you put it, the upper half of the ICE region. FYI, contrary to what you have read, it does not necessarily send extra power to the battery. It is more efficient than pulsing slowly. At lower speeds (< 46 mph), it is best not to drive just slightly past the midline (50-55%). The pulse zone in that image you posted is the correct area to be when pulsing.
I agree. The US Department of Energy did a study on the 2010 Prius and determine when the ICE is fully warmed up that its most efficient operational range is from 1250 to 1600 RPM. this corresponds to about 60% to 90% on the HSI Eco bar(or between .80 to 1.20 gallons per hour if you have a scangaugeII) . In this range the Prius ICE is has about a 35% to 38% gasoline energy to engine output power conversion. However, the most important aspect of the pulse is the final speed you reach at the end of the pulse, because you don't want that speed so high that if you have to stop that the you lose too much energy - which is an important factor in urban/suburban driving where there are alot of events that may require you to do a full stop. In non-stop flat highway driving, wind resistance tends to limit the effectiveness of P&G to a top speed of about 50 mph. A long downhill grade or a tailwind can make all the difference here.. The trick is being able to identify when you have a tailwind that you can use... P&G produces its best fuel efficiency results on empty flat country roads if you can pulse to a top speed of 38 mph and then glide until you get to about 23 mph and then repeat over and over again. At under 40 mph - wind resistance is less of a drag. It seems to me that when the ICE is running at the low end of its most efficent power range on a flat smooth surface the Prius tends to slow tread up to about 35 to 40 mph Ideally the top pulse speed is 38 mph, the Prius is warmed up, the outside temperature is 72 F degrees, there's miles of flat very smooth asphalt road in front of your car with no traffic, the Prius is fitted with low rolling resistant tires, the tires are inflated at the maximum sidewall pressure), the windows are all rolled up, the AC/heater/defroster is off, and you have a tail wind, and you have a tank full of 100% gasoline. If you have slightly hilly roads then try to synch each pulse to a downhill grade section of the road and try to glide on the uphill.
