I've been doing alot of P&G lately... it seems alot of people feel that the best way to do this is to accelerate aggressively to the top of the desired speed range. My question is: are these frequent spikes in RPM bad for the ICE? Thanks!
Do you mean "Pulse" and Glide... Pump works too I guess In any case what do you mean "spikes in RPM"? How high is your pulse in terms of RPMs? Are you flooring it? That would probably be harmful after a while but really the car will take care things and try to keep the ICE in its most efficient zone. I would suggest try the first couple thousand miles just "driving" the car. Once you have a base line, then try the P&G to see if you are actually benefiting from the method. I know I was trying to hard when I first got mine. I think I ended up hurting the FE more than I helped it. Welcome by the way!
lol yes I meant pulse. I don't floor it, but I do go into the "PWR" line when going from a stop light to 40mph. The MPG on my last tank was 54mpg indicated and 50mpg actual. Not bad for my 3rd tank!
Hi Chale, For best mileage, you do not want to force the gas-electric cycle. That is, during accelleration, try to get off the battery as soon as possible and hold a steady accellerator pedal without charging the battery. Torwards the end of the accelleration, pull back on the pedal and get some engine recharge to make up for the battery usage at the start of the accell. The feedback from the Gen II MFD makes it easier to train one's self to where the pedal should be for the pump (pulse). This may be more difficult with the Gen III displays. My understanding of where the optimums were required the use of even more advanced system displays, that I no longer use. But, that is another story. The optimum Gen II Pulse RPM is 1800 to 2200 RPM. This level of accelleration is moderate in a Gen II, and typical of other cars around here. There are people who accellerate allot faster, but many who go about this same rate. The bigger engine in the Gen III may require a quicker acceleration to get the engine at its optimum efficiency.
So what you're saying is that when I accelerate up to my pulse speed I should be using ALL ICE, and no battery?
Hi Chale, The battery use is unavoidable right at the start. But during the middle 50% of the pulse, yes - no battery (on level terrain). But enough pedal to keep the engine in its efficient range. Which means mostly above 1800 RPM in a Gen II. Not sure for a Gen III.
Yep, all ICE is most efficient. Charging and discharging a battery always wastes energy. Don't worry about RPM spikes. The computers protect the engine so it never redlines.
I disagree with the 1st assumption. ICE is most efficient in a narrow band of both rpm and charge. At the level required to get better SFC, it is at a speed and constant charge, which may not be suited to the road requirements. If you have 220g/kwh SFC available (it is the BSFC), but the service does not apply safely - lane occupancy, eg., you cannot get to that, having to moderate throttle pressure. In those conditions, probably the whole efficiency of HSD (ICEfor periods+MG1/MG2+NiMH) can be better... And there is another issue, many times you have a PSD reduction ratio depending on a MG working to provide the desired ratio (it is not 1:1), which itself is a loss...and ICE is working...so keeping ICE in service all the times may not be the ultimate choice. HSD does that judgement for us, fortunately!
