Why not glide in "EV"?
#1
Why not glide in "EV"?
In discussions on Pulse and Glide, it sounds like everyone is trying to avoid gliding in "EV." Why? I find you can go pretty far gliding in EV. Once I get up to the speed I want, I tap the gas again lightly or slightly tap the brake pedal into "EV" and glide along. Of course, uphill this does not work.
#2
Re: Why not glide in "EV"?
I dunno, I do it all the time. I've changed my commute to driving through some towns instead of the interstate because my FE jumped this summer while driving that route. And that drive means lots of 25-40 mph driving, and a couple of hills, and I spend a lot of time in EV mode. Either coasting, pushing EV sometimes to accelerate gas-free, or just trying to hold steady. When I push a little too hard and the ICE kicks in I go with it and give myself a bit of a "pulse" to keep the battery from dropping too low. *shrug* Works for me.
#4
Re: Why not glide in "EV"?
I've been looking, but I haven't seen any negatives on this. I have a stretch along a FWY where the speed limit is 35 and is relatively flat. I try to keep the ICE off as much as possible along this stretch, and find if I lightly apply pressure to the accelerator, I'm able to maintain my speed.
#5
Re: Why not glide in "EV"?
The only thing I can imagine, and this is only a wild guess, is that they designed the car not expecting the constant start up and shut down of the engine. Is it possible that the constant on and off adds more stress (assuming that causes stress) than driving normally (foot on gas) whilst on highways. More wear and tear on the engine, translating into mechanical problems down the road?
Again, this is only a wild guess.
Again, this is only a wild guess.
#6
Re: Why not glide in "EV"?
It doesn't bother the Prius, and I don't have any evidence to indicate that it is any problem for the Camry. I have done this since day 1 on my TCH without any issues. I don't relate it to P&G because there is no deliberate speed change in the strategy.
Early on, I found the P&G was not a practical matter in the TCH because of its weight and power. It was/is very hard to keep the car in the stealth range (zero current area between battery dischage and battery charge) during a glide -- possible, but requires a light touch and concentration.
I resorted to maintaining an EV only speed at 40-42 miles per hour (Level terrain, more down, less up) as much as possible consistent with traffic conditions. My morning commute has a stretch of about five miles in it where I do this twice daily. The distance that I run depends on the SOC, but several miles at a time is typical. LIke you, I simply increase pedel to start the ICE if I hit a small hill or demand below sufficient battery state, then it's right back to EV as soon as everything is squared away again.
Early on, I found the P&G was not a practical matter in the TCH because of its weight and power. It was/is very hard to keep the car in the stealth range (zero current area between battery dischage and battery charge) during a glide -- possible, but requires a light touch and concentration.
I resorted to maintaining an EV only speed at 40-42 miles per hour (Level terrain, more down, less up) as much as possible consistent with traffic conditions. My morning commute has a stretch of about five miles in it where I do this twice daily. The distance that I run depends on the SOC, but several miles at a time is typical. LIke you, I simply increase pedel to start the ICE if I hit a small hill or demand below sufficient battery state, then it's right back to EV as soon as everything is squared away again.
#7
Re: Why not glide in "EV"?
I would imagine you're talking about hypermile techniques (or whatever it is called) and the reason they try to avoid coasting in EV mode is simple : they feel whatever energy you use in EV mode will have to be replaced later by using ICE and efficiency of energy conversion from electric (actually chemical, but let's make it simple) to mechanical (driving in EV) and later from mechanical to electrical (recharging batteries afterward) is not 100%, but it is about 90%-95% and therefore, since you have 2way conversion netting 80% to 90% efficiency, some people feel they get better MPG by keeping the ICE on all the time and never use EV mode. I don't use this type of driving, so I don't have personal experience, but my gut feeling is they're partially wrong and in some cases it's better to coast in EV and in some it's not depending on particular situation (for example driving up the hill in EV will deplete battery too quickly, driving down the hill with ICE running wastes energy).
I don't think Haroldo wild guess is even on the same page, so to speak, no offense intended, please.
I don't think Haroldo wild guess is even on the same page, so to speak, no offense intended, please.
Last edited by Pete4; 03-06-2008 at 01:14 PM.
#8
Re: Why not glide in "EV"?
Sorta like golf where you try to shoot your age, see if you can get a MPG higher than the average temp.
#9
Re: Why not glide in "EV"?
The only thing I can imagine, and this is only a wild guess, is that they designed the car not expecting the constant start up and shut down of the engine. Is it possible that the constant on and off adds more stress (assuming that causes stress) than driving normally (foot on gas) whilst on highways. More wear and tear on the engine, translating into mechanical problems down the road?
Again, this is only a wild guess.
Again, this is only a wild guess.
The Atkins cycle engine in the TCH runs at rather low rpm at highway speeds. I don't know where the red line is. Mine seldom goes over 3000 rpm, even when climbing rather steep grades in the mountains. I would think it would run as long as any engine, being designed to start and stop so much.
Last edited by rburt07; 03-07-2008 at 02:42 AM.
#10
Re: Why not glide in "EV"?
In discussions on Pulse and Glide, it sounds like everyone is trying to avoid gliding in "EV." Why? I find you can go pretty far gliding in EV. Once I get up to the speed I want, I tap the gas again lightly or slightly tap the brake pedal into "EV" and glide along. Of course, uphill this does not work.