[garyd9]

In trying to better understand how to drive a "hybrid", I've spent a significant amount of time googling. One thing that seems to be described in many posts and articles is a certain state that can be reach by accelerating to speed, completely backing off the pedal, and then VERY gently tapping it. Apparently, with this action, you get into a state where the battery is neither charging nor is it providing power to the wheels.

However, I can't seem to achieve this state at all with the RAV4. If I completely release the gas pedal, the wheels are charging the battery. No matter how gently I try to apply pressure to the pedal, it'll immediately jump from that state to the state where the battery is powering the wheels. There doesn't seem to be any in-between.

Is this state reachable with the RAV4 hybrid? Does it even really matter if it's not?

Thanks
Gary

 

[turbotom]

Not sure I understand. Why would you want to have - "a state where the battery is neither charging nor is it providing power to the wheels." ? I think the only way to get into this state is by putting the car in neutral. One day I coasted down my driveway in neutral and it appeared the hybrid system had more less turned off.

"One thing that seems to be described in many posts and articles is a certain state that can be reach by accelerating to speed, completely backing off the pedal, and then VERY gently tapping it." With this action you get the car up to speed and then back off the gas pedal (all the way off) and the gas engine turns off and you are in EV only. Then by gently tapping the gas you are able to drive in EV only mode for a while. I posted a video last month showing this.

 

[rdgrimes]

In trying to better understand how to drive a "hybrid", I've spent a significant amount of time googling. One thing that seems to be described in many posts and articles is a certain state that can be reach by accelerating to speed, completely backing off the pedal, and then VERY gently tapping it. Apparently, with this action, you get into a state where the battery is neither charging nor is it providing power to the wheels.

However, I can't seem to achieve this state at all with the RAV4. If I completely release the gas pedal, the wheels are charging the battery. No matter how gently I try to apply pressure to the pedal, it'll immediately jump from that state to the state where the battery is powering the wheels. There doesn't seem to be any in-between.

Is this state reachable with the RAV4 hybrid? Does it even really matter if it's not?

Thanks
Gary

There's a certain amount of drag (charging) built into the system. When you let off the throttle its activated. It's meant in part to simulate the normal engine braking that any car has. Of course it also helps charge.
But what you describe isn't really "gliding", its more part of a hyper-miling technique meant to extend how far the car can go without expending any energy. A Prius has VERY little drag, unlike a Rav4 which has quite a bit so its arguable how much this technique might help with MPG. But if you watch the hybrid gauge closely you'll see there's a space between the charge and ECO zones that represents that state of nothingness. You can force the same state by shifting to neutral. Watch the gauge, not the energy display. The energy display is a second or 2 behind.

"Gliding" refers more to just coasting with your foot off the gas. Spending the most possible time and distance in EV mode is the key to max MPG. So the idea is to accelerate briskly to speed, then let off the gas to trigger EV mode. Then you can add power slightly - keeping it in EV mode - to extend your coasting range. On flat/level ground you can go a long ways in EV mode (up to 47mph). The more energy you apply, the faster the traction battery drains so there's a limit. But if you stay in the lower range of the EV zone you can go a long way. Draining the battery and forcing the ICE to run is bad, and eliminates any gains achieved in the first place. So sometimes you want to accelerate - glide - accelerate - glide - like that, using EV power to extend the glide. Maximize the time and distance spent in EV without draining the battery to the point that charging is forced.

The Rav4 has a lot of drag, so its arguable whether any hyper-miling techniques will have much impact. But pulse-n-glide techniques certainly will.

 

[garyd9]

The "glide" state I'm trying to describe is talked about here:

Simple instructions on how to go into "stealth" or glide mode? | PriusChat

and here:

Pulse and Glide plus Warp Stealth in the Prius II for maximum FE … | CleanMPG

(and many other places... just google for "prius glide")

 

[garyd9]

Watch the gauge, not the energy display. The energy display is a second or 2 behind.

Please forgive me... Which display should I be noting? There's the one with the diagram of the car with icons for the motors, ICE and battery (which is the one I usually watch) and then one for "trip information" and another for "history" (or something like that..it spans several days.)

The Rav4 has a lot of drag...

Fortunately, my specific daily commute is all 35 MPH roads, so the drag impact isn't too terrible. (On the other hand, I have lots of Western PA hills to deal with...)

 

[Eug]

The best way to save gas is just to maintain a constant (low) speed. When you do have to accelerate, just do so very, very gently.

However, doing this is really irritating, so these days I mostly don't bother. I'm less aggressive with my driving than I used to be, and part of that may be related to the feedback that hybrids provide to push us to save gas, but it's also partially because I have kids in the car now.

 

[rdgrimes]

Please forgive me... Which display should I be noting? )

The hybrid gauge. That's the big round thing next to the speedo.
The energy display on the nav screen isn't very useful, just entertaining.

The best way to save gas is just to maintain a constant (low) speed. When you do have to accelerate, just do so very, very gently.

That's actually not correct. As often as not its best to accelerate briskly (staying in ECO zone as much as possible) so you can drop into EV mode sooner. The most time and distance spent in EV mode wins the MPG race. If it takes you all day to get up to speed you'll spend less time in EV mode.

 

[garyd9]

I guess I need to keep playing around and trying to see what works best for me and my commute. In way, I have it easy in that the speed limit for my entire daily commute is 35 MPH (which lessens impact of drag.) On the other hand, I have hills, more hills, and even the "flat" areas are just "flat" constant uphill or downhill. (I'm originally from Florida... a very FLAT state. My first impression of Western PA roads was that Disney World's "roller coaster" division must have designed all the roads out here.)

I'm averaging 36-37 MPG so far (on the car's computer) still on my first tank of gas, so perhaps I'm doing something right just driving the same way I drove my Mazda CX-5. (Actually, that's not completely true... in the CX-5, I tried to avoid braking. In this hybrid, I don't feel as if braking is a complete waste of energy.)

 

[rjw972]

The hybrid gauge. That's the big round thing next to the speedo.
The energy display on the nav screen isn't very useful, just entertaining.


That's actually not correct. As often as not its best to accelerate briskly (staying in ECO zone as much as possible) so you can drop into EV mode sooner. The most time and distance spent in EV mode wins the MPG race. If it takes you all day to get up to speed you'll spend less time in EV mode.

Agreed, if you accelerate slowly not only will you spend less time in EV mode but you'll make drivers behind you mad. Better get used to the slow lane and unfriendly "gestures" if you do that. :wink

I drive a 2015 Lexus NX 300h FWD and live in Texas so I commute long distances mostly with hills here and there and uneven pavement and mostly city driving and about 30% highway. The most I could achieve was 38.8 mpg (without "hypermiling") and as of late since refilling a couple of days ago I'm currently 130.5 miles into my drive and getting 43.7 mpg; that will go down for sure since my next few days will consist of short commutes. :frown

 

[Eug]

That's actually not correct. As often as not its best to accelerate briskly (staying in ECO zone as much as possible) so you can drop into EV mode sooner. The most time and distance spent in EV mode wins the MPG race. If it takes you all day to get up to speed you'll spend less time in EV mode.

Well, the point is if you stay in eco zone, you can't accelerate briskly. It takes a delicate touch just to stay in eco.

 

[garyd9]

Well, the point is if you stay in eco zone, you can't accelerate briskly. It takes a delicate touch just to stay in eco.

If I stayed in the "eco" zone, I'd never even get out of my neighborhood. I was serious about those hills... I'm not talking about hills. I'm talking about HILLS.

 

[rdgrimes]

Well, the point is if you stay in eco zone, you can't accelerate briskly. It takes a delicate touch just to stay in eco.

Not really. Put the system in ECO mode and you have plenty of throttle control. Pulling away from a light, the RAV4 HV can stay ahead of most others without going into the power zone. About the only time you really need the PWR zone is going uphill. Even then, the less time you spend in the PWR zone, the better - so get up that hill quickly. Even on a fairly steep hill, PWR zone is only needed to get up to speed, and ECO will keep you at speed.

Anyhow, that hybrid gauge in the Rav4 is wonderful - much better than previous Prius gauges. It tells you everything you need to know to drive with max efficiency.

 

[Torque]

I tried coasting in Neutral today it seem to just glide forever.

So when you are in ev mode with the indicator showing and 0 rpm om the ICE isnt coasting in neutral the most efficient way to go? There is alot of drag by just lifting the throttle, then the battery is charged followed by use of the battery. I'm thinking if this efficiency loss is avoided by just going to N right? You gain some more distance instead of charging the battery.

Is there any extra wear by putting it in N when ICE is off?


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[rdgrimes]

I tried coasting in Neutral today it seem to just glide forever.

So when you are in ev mode with the indicator showing and 0 rpm om the ICE isnt coasting in neutral the most efficient way to go? There is alot of drag by just lifting the throttle, then the battery is charged followed by use of the battery. I'm thinking if this efficiency loss is avoided by just going to N right? You gain some more distance instead of charging the battery.

Is there any extra wear by putting it in N when ICE is off?

"N" is an electrical state, everything is still turning. But yes, its "drag free". You can achieve a similar result with careful throttle control to keep the charge needle at the "0" point. (This is where ECO mode is helpful).

But you can gain speed on a downhill stretch using N or throttle control. So that's sometimes a benefit. There's no "one thing is always best" answer, sometimes you want the drag and charging.

 

[internalaudit]

I tried to pulse and glide and the the drag seems to not make it feasible. The speed just drops quickly when I take my foot of the gas pedal after hitting 3-5 over my ideal mph.

I can keep the car in EV mode if I hit the ideal speed then lightly step on the gas pedal.

 

[rdgrimes]

I can keep the car in EV mode if I hit the ideal speed then lightly step on the gas pedal.

Yes well that's the "glide" part, that's what you're supposed to do. You just need to watch the battery charge and not let it get too low.

 

[internalaudit]

Yes well that's the "glide" part, that's what you're supposed to do. You just need to watch the battery charge and not let it get too low.

And the pulse is the application of the gas pedal, with the gasoline engine turning on?

 

[Torque]

I'm able to hit 50 US MPG to and from work now playing with the neutral thingie. Trying to achieve neutral state using the gas pedal in ECO mode is more difficult than to hover in a helicopter so I play with the stick.

Also below 6-7mph the brakes are fighting the motors in stop and go situations, any comments on that? What is the actual amp draw sitting in D with brakes engaged? There seems to be a substantial force forward when in D.




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[Torque]

RAV4 Hybrid vs Prius "gliding"