Larry--

You still seem to be misunderstanding, so I must be doing a poor job of explaining. I'll give it one more shot. EV mode is defined as ANY time you are driving purely as an electric vehicle. This means any time when your instantaneous FE needle is in "E mode", the blue region beyond 60 mpg. In other words, times when you're using battery ONLY, for power. There is zero requirement that you sit for 7 seconds at a stop for EV mode. ANY time the ICE turns off leaving you able to drive on battery you are by definition in EV mode.

The 7 second shutdown is what gets you into what's been called "full hybrid" mode. In full hybrid mode, which is more or less a threshold (once you get into "full hybrid" mode, you're generally there for the remainder of the trip, regardless of switches between ICE/EV driving), your car is able to _freely_ flip back and forth between ICE and EV modes on the fly, as needed. EV mode is an instantaneous/"tactical" condition, full hybrid is more of a strategic one. If you're not in "full hybrid" mode, when your ICE turns on you will ONLY be able to go back into EV mode (have the FE needle drop into blue "E mode" on the dial) by EITHER: a) (while the car is warmed up) coming down from 40-45 mph or higher, or b) (while the car is warmed up) coming to a complete stop until the ICE cuts out. These are the only ways to get the car into EV without being in "full hybrid" mode. In full hybrid mode, any time (when the car is warm) you take your foot off the accelerator and coast, if your speed is under 40 mph, it should quickly drop into EV mode WHILE driving.

Again, it is possible to be in EV mode (due to dropping from higher speed or starting from a stop) without being in full hybrid mode, but as soon as you kick the ICE on by accelerating beyond what you can do in EV mode, you will once again be stuck in ICE mode until you do one of those two things again (stop, or come down from 40+ mph). And it is possible to be in full hybrid mode without being in EV mode, because any time you hit the gas strongly you will fire up the ICE and no longer be in EV mode--but in full hybrid mode as soon as you remove your foot from the pedal (under 40 mph) you should quickly drop back into EV mode as the ICE turns back off.

And one more angle--if the ICE is on you are by definition NOT in EV mode. However it's entirely possible for the ICE to be running in "full hybrid" mode. Full hybrid mode requires the engine to be warmed up, maybe 1-2 miles of driving (from my experience), and a stop which takes ~7 seconds for the ICE to cut out, to enter. But once in full hybrid mode you should be good for the rest of the trip.

At this point if I still haven't explained it well enough I think I'm giving up, hehe.

 

You did a great job, Thanks!

 

chestr - I think you identified the source of confusion for many in this forum. EV is not equal to "full-hybrid" - I suspect many people believed those to be equivalent. I like your phrasing that EV is 'tactical' while "full-hybrid" is 'strategic'.

 

Chestr thanks for the great explanation. I remembered reading about the different modes when I was first looking into the TCH a while before I bought it. I had realized that sometimes when driving that when I would slow down from above 40 that the needle would automatically bottom out to e-mode and other times it wouldn't. I my drive home from work today I paid attention to this and noticed that it would bottom out to e-mode as described whether I was slowing to stop or slowing due to speed or traffic conditions.

What impact on MPG does the different modes have? When in e-mode are you getting a higher mpg vs being at the border of 60mpg\e-mode? I realize that when you are in e-mode that you aren't using gas so you are basically increasing the amount of miles divided by the gallons consumed which will cause the mpg avg to increase. Is there much of a difference in the affect of either position?

 

Glad the explanation helped.

But yeah as you say, being in E mode (aka EV), you're technically getting infinite mpg, because if you divide even 1 mile/0 gallons that is an undefined result mathematically. The effect of this is that if you can drive say 1 mile getting 30 mpg and 1 mile in EV so you use no more gas, you've now gone twice as far on the same amount of gas--aka 60 mpg. And it's easy to get these results to show--briefly. If you fill up your tank when the car is nice and warm and especially if it's in full hybrid mode when you fill up, if you leave the MFD (don't know about Nav options) on the tank FE gauge, when you get moving and start going in EV mode the FE readout will quickly shoot up as high as 99.9 mpg, until you actually cover enough ground or change speeds requiring you to kick the ICE on. Basically if you could (somehow) run in EV mode half the distance you travel, you would double your mpg. So the more you drive in EV (as long as you have a good sense of how to drive when you're burning gas so you won't blow away the benefits), the higher your potential FE could go. So part of the trick when you're driving in conditions when you can really take advantage of EV is to know when to hit the gas so you don't empty the battery. When the battery gets too low, the ICE will kick on and burn fast trying to recharge, and won't stop until the charge is high enough, so you lose efficiency there--especially if you're stopped in traffic at the time and can't move! This is why I almost always have my MFD on the battery display so I can constantly monitor my battery and switch more to P&G when it gets too low to sustain steady EV mode.

And the benefit of "full hybrid" is basically just that you can drop freely into EV mode any time you're going 40- and take your foot off the gas. Otherwise you'll be burning fuel when you don't need to, and it all adds up.

As for EV mode vs just bottoming (topping?) out the FE gauge, thing is while you're driving with the ICE going, any pressure on the accelerator will cause it to feed more fuel to accelerate the car. Even when it's showing 60mpg because you've been coasting but aren't in EV mode. But when you get it over to EV, you can then drive solely on battery, including speeding up. You have to learn to get the feel for how much pressure you can apply to the accelerator before it fires up the ICE (and I think it's more tolerant in warm weather, another loss in winter), but if you keep a light foot on the pedal it's entirely possible to maintain speed, accelerate, even drive up hills, purely in EV mode, when using the ICE accelerating and hills would drop your FE down to 10-30 mpg because they always require more gas to produce the power to do those things.

Hope this helps explain the benefits a bit more. And yeah, don't worry, hills are tricky, lol. And you will slow down on any meaningful hill, but I hit one significant hill and manage stretches of it in EV mode which I figure has to be saving me some fuel because burning gas the FE would drop pretty low.

 

I'm sure it was written in one of the 65 other posts on this topic, but what is happening when it shows 60MPG?
You're coasting (albeit not in stage 4) and the engine is (theoretically) not running...or is it? If you're coasting with a cold engine at 30 MPH, are you burning gas when the needle is at 60MPG?

 

First I always have the MFD displaying the battery\Ice. I also usually keep the consumption screen up on the Nav display.

As far as being at 60MPG I have this happen sometimes when I am coasting and other times the MFD shows dual power (Ice\Electric).

I think I have caught on pretty quick, with some help from this site, as to how to feather the pedal to get into E-mode and how to deal with hills. On some of the different routes I drive I will try and reach the speed limit +5mph by the crest of the hill, while in E-mode, so that after I crest I will start to go more than +5mph over and thus get a little brake regen in while I get myself back closer to the speed limit. I have noticed that as it has warmed up I have been able to achieve E-mode right up to 45mph at times.

I have already seen the 99mpg figure after refueling. It was quit amusing.

"If you're coasting with a cold engine at 30 miles per hour, are you burning gas when the needle is at 60MPG?" I had wondered this too. As both the MFD and the Energy screen show the ICE is off.

 

My understanding is that when you're going faster and pull your foot off the pedal you're in "fuel cut" mode where things are spinning but fuel is not actually being burned, but as far as I know that's specifically for 40+ speeds. I can't say for sure what state it's in when it's at the 60mpg spot, though I'm sure it can go higher than 60 in reality. It's not impossible it shuts off gas flow then as well. Though the other considerations are at least as important, because 60+ mpg vs no gas at all is fairly small difference, but the fact you can't accelerate or go uphill when you're not in EV mode without the FE dropping way down will make more of a difference.

 

When the gauge FE reads precisely 60 mpg (or precisely 0 L/100 km in the Canadian version) when coasting at speeds above ~40 mph (~64 km/h), you are in "fuel-cut" mode — the ICE is burning absolutely no fuel, but is being spun at ~1000 rpm by MG1 (for various protective reasons discussed in detail in other threads — search on "fuel cut"). In pure-EV mode, the ICE is not spinning at all, and so is also burning no fuel. In fuel-cut mode, however, the work done spinning the ICE wastes energy.

Maximizing pure-EV mode operation sounds desirable at first sight, but does not necessarily improve overall FE. The recharging of the battery takes gasoline, and unless you can beat Toyota's control system, it's likely that you'll actually end up worse off by trying to maximize EV mode. See the thread "An Unpalatable Fact (with apologies to Al Gore!)" for a lot more on this.

Stan

 

So (if I understand it correctly) there is no difference in fuel consumption if you are at full battery and coasting to an eventual stop with the needle at 60MPG versus one where the needle is 'in the blue'.
Right?