JimboK
01-28-2007, 07:44 PM
I figured I'd finally check in here and provide some details of my driving techniques and commuting routines. Better late than never! So here’s my essay.
I think I’ve pretty well mastered pulse & glide and use it whenever practical. If the battery SoC is high enough I use EV mode (by feathering the pedal, no EV switch) for short bursts when practical to extend a glide a short distance, to drive through parking lots, or to move between closely spaced red lights. I minimize EV mode, though, to avoid draining the battery too much, and I limit it to when I know subsequent driving will likely recharge the battery.
At 42+ MPH I decelerate using warp stealth whenever I can.
I mostly avoid the freeway, using it mainly when no other practical route exists or time is an issue.
I use DWB within limits, but not to the extreme of some. (Sorry, Wayne, I still have a touch of impatience that keeps me from coasting at less than 10 MPH for a quarter mile as I approach every stop sign or red light.) I apply a technique I learned in driver’s ed thirty-something years ago but never used until the last few months: watching for stale green lights and expecting them to turn red, in glide or warp stealth (depending on speed) mode as I approach.
I have a ScanGauge mounted next to the MFD on which I watch RPM and coolant temperature. I’ve also been switching among other SG ICE parameters to try to figure which are most helpful for facilitating maximum FE. I’m currently watching throttle position and ignition timing.
Of the SG readouts, I watch RPM most closely. (It’s a shame Toyota didn’t put a tach in the car!) My goal for mid- to high-speed cruising is 1700, which based largely on Hobbit’s work I figure is the Prius equivalent of DWL. I try to stay below 2000 for acceleration unless traffic and safety dictate otherwise. I try to maintain 1500 as an absolute minimum to keep the ICE out of its inefficient “loafing” range.
I’ve blocked the front grill with foam pipe insulation to allow more rapid ICE warming in cold temps.
I refered to commuting routines in the plural because I have two full time commute routes and a number of part time work sites. The full time commute depends on whether it starts or finishes at my fiancee's house or my landlady's house. The latter is my official residence though I spend more time at the former. Either is about 8-9 miles from work, and almost all on two-lane roads. Even at 6:30 a.m., most of them have at least moderate traffic.
[Edit: I measured both routes precisely this week. From my fiancee's house is 8 miles, from my landlady's it's 10.]
The route from my fiancee’s house is about 2 miles of 45 MPH on one road, then a turn onto another that starts at 55, drops to 50, then to 45. Between the speed limits, the traffic, and a few blind curves, P&G is mostly out of the question. So I pretty much maintain the prevailing speed. The road seems pretty flat for all but the last half mile, but there actually is a nearly imperceptible uphill for the first two miles. This allows me, after getting up to speed, to maintain cruising RPM at my goal of 1700 without gaining speed. The next 3+ miles are a slight downhill, as subtle as the previous uphill. Maintaining 1700 then causes gradual acceleration, so I allow the acceleration until I approach traffic or reach maximum speed (based on speed limits or safety). I then back off in warp stealth until either I can safely accelerate again or I hit the last segment. That segment, again, is 45 MPH, and begins with a short but pretty steep downhill stretch, ideal for warp stealth unless traffic in front is braking for a curve in the middle of the hill. It then more gradually goes uphill until it hits a stop light. My office is a block from the light. The total commute time is about 12 minutes, so the ICE just barely gets up to optimal temp.
From my landlady’s house I begin on her quarter-mile gravel driveway. It’s mostly uphill, quite steep at the beginning and then gradually leveling off. On a cold morning, with the uphill and the gravel (I don’t want dozens of rock scars on my car’s body), efficiency is out the window: The RPM stays low, it often pulls from the battery despite my best efforts, and I can’t do EV mode. Her driveway becomes the hard surface subdivision road, with about a half mile of hills to the main road, still inefficient as the ICE has only partly warmed. I shift to neutral on the downhills to get any kind of cool-ICE glide I can. From there to my office is a mixture of speed zones from 35 to 55, again mostly on two-lane roads, with several turns from one onto the next. Some are flat, others have gentle to moderate hills. So my driving is a mixture of styles: true P&G when the ICE warms and when traffic and road conditions allow, more conventional driving (especially in the 55 MPH segment), or a higher speed variant of P&G. Total commute time is generally about 15-20 minutes, more if I can pull off some good P&G segments.
These days with the cold weather I’ve been lucky to get 45-50 MPG commuting from either place. Evening commutes are a little better, between the warmer temperatures, slightly more favorable elevation changes in the return direction, and somewhat lighter traffic. But then FE takes a hit when I stop at the state park on the way home and hit the jogging trails, which I (try to) do two or three times a week.
My part time work sites are across town, between 15 and 27 miles depending on where I start and finish. I have several options for routes, most with favorable road and traffic conditions. There are many P&G opportunities, though some are in urban sections with a lot of stoplights. I’ve been watching and trying to learn the timing of the lights to optimize my glide timing. Between the distance and the routes I can generally get at least 60 MPG, and when the weather was warmer I easily achieved 70+ for some of them. (If that was my daily commute I think I could give VaBeachPrius a run for his money!) I’m still experimenting with minor alterations in the routes to determine the best ones overall.
One major limiting factor is the river that runs through the middle of the city. By far the most convenient bridge to use is one of the freeways. To use one of the others takes me several miles out of my way, adding at least 15 minutes to my commute time even with traffic flowing smoothly. Add rush hour traffic to the alternate routes and bridges, and the delay could be substantial and unacceptable. So I generally take the freeway bridge, at least during rush hour. Fortunately, the freeway stretch is only a couple of miles. I have pretty good access and exit options on both sides of the river. During off hours I'm more likely to use one of the other bridges.
There you have it. Not sure how much more I can do; I’ve learned from some of the best here already. I’ll just keep fine-tuning and studying from the masters!
I think I’ve pretty well mastered pulse & glide and use it whenever practical. If the battery SoC is high enough I use EV mode (by feathering the pedal, no EV switch) for short bursts when practical to extend a glide a short distance, to drive through parking lots, or to move between closely spaced red lights. I minimize EV mode, though, to avoid draining the battery too much, and I limit it to when I know subsequent driving will likely recharge the battery.
At 42+ MPH I decelerate using warp stealth whenever I can.
I mostly avoid the freeway, using it mainly when no other practical route exists or time is an issue.
I use DWB within limits, but not to the extreme of some. (Sorry, Wayne, I still have a touch of impatience that keeps me from coasting at less than 10 MPH for a quarter mile as I approach every stop sign or red light.) I apply a technique I learned in driver’s ed thirty-something years ago but never used until the last few months: watching for stale green lights and expecting them to turn red, in glide or warp stealth (depending on speed) mode as I approach.
I have a ScanGauge mounted next to the MFD on which I watch RPM and coolant temperature. I’ve also been switching among other SG ICE parameters to try to figure which are most helpful for facilitating maximum FE. I’m currently watching throttle position and ignition timing.
Of the SG readouts, I watch RPM most closely. (It’s a shame Toyota didn’t put a tach in the car!) My goal for mid- to high-speed cruising is 1700, which based largely on Hobbit’s work I figure is the Prius equivalent of DWL. I try to stay below 2000 for acceleration unless traffic and safety dictate otherwise. I try to maintain 1500 as an absolute minimum to keep the ICE out of its inefficient “loafing” range.
I’ve blocked the front grill with foam pipe insulation to allow more rapid ICE warming in cold temps.
I refered to commuting routines in the plural because I have two full time commute routes and a number of part time work sites. The full time commute depends on whether it starts or finishes at my fiancee's house or my landlady's house. The latter is my official residence though I spend more time at the former. Either is about 8-9 miles from work, and almost all on two-lane roads. Even at 6:30 a.m., most of them have at least moderate traffic.
[Edit: I measured both routes precisely this week. From my fiancee's house is 8 miles, from my landlady's it's 10.]
The route from my fiancee’s house is about 2 miles of 45 MPH on one road, then a turn onto another that starts at 55, drops to 50, then to 45. Between the speed limits, the traffic, and a few blind curves, P&G is mostly out of the question. So I pretty much maintain the prevailing speed. The road seems pretty flat for all but the last half mile, but there actually is a nearly imperceptible uphill for the first two miles. This allows me, after getting up to speed, to maintain cruising RPM at my goal of 1700 without gaining speed. The next 3+ miles are a slight downhill, as subtle as the previous uphill. Maintaining 1700 then causes gradual acceleration, so I allow the acceleration until I approach traffic or reach maximum speed (based on speed limits or safety). I then back off in warp stealth until either I can safely accelerate again or I hit the last segment. That segment, again, is 45 MPH, and begins with a short but pretty steep downhill stretch, ideal for warp stealth unless traffic in front is braking for a curve in the middle of the hill. It then more gradually goes uphill until it hits a stop light. My office is a block from the light. The total commute time is about 12 minutes, so the ICE just barely gets up to optimal temp.
From my landlady’s house I begin on her quarter-mile gravel driveway. It’s mostly uphill, quite steep at the beginning and then gradually leveling off. On a cold morning, with the uphill and the gravel (I don’t want dozens of rock scars on my car’s body), efficiency is out the window: The RPM stays low, it often pulls from the battery despite my best efforts, and I can’t do EV mode. Her driveway becomes the hard surface subdivision road, with about a half mile of hills to the main road, still inefficient as the ICE has only partly warmed. I shift to neutral on the downhills to get any kind of cool-ICE glide I can. From there to my office is a mixture of speed zones from 35 to 55, again mostly on two-lane roads, with several turns from one onto the next. Some are flat, others have gentle to moderate hills. So my driving is a mixture of styles: true P&G when the ICE warms and when traffic and road conditions allow, more conventional driving (especially in the 55 MPH segment), or a higher speed variant of P&G. Total commute time is generally about 15-20 minutes, more if I can pull off some good P&G segments.
These days with the cold weather I’ve been lucky to get 45-50 MPG commuting from either place. Evening commutes are a little better, between the warmer temperatures, slightly more favorable elevation changes in the return direction, and somewhat lighter traffic. But then FE takes a hit when I stop at the state park on the way home and hit the jogging trails, which I (try to) do two or three times a week.
My part time work sites are across town, between 15 and 27 miles depending on where I start and finish. I have several options for routes, most with favorable road and traffic conditions. There are many P&G opportunities, though some are in urban sections with a lot of stoplights. I’ve been watching and trying to learn the timing of the lights to optimize my glide timing. Between the distance and the routes I can generally get at least 60 MPG, and when the weather was warmer I easily achieved 70+ for some of them. (If that was my daily commute I think I could give VaBeachPrius a run for his money!) I’m still experimenting with minor alterations in the routes to determine the best ones overall.
One major limiting factor is the river that runs through the middle of the city. By far the most convenient bridge to use is one of the freeways. To use one of the others takes me several miles out of my way, adding at least 15 minutes to my commute time even with traffic flowing smoothly. Add rush hour traffic to the alternate routes and bridges, and the delay could be substantial and unacceptable. So I generally take the freeway bridge, at least during rush hour. Fortunately, the freeway stretch is only a couple of miles. I have pretty good access and exit options on both sides of the river. During off hours I'm more likely to use one of the other bridges.
There you have it. Not sure how much more I can do; I’ve learned from some of the best here already. I’ll just keep fine-tuning and studying from the masters!