jbm79

On my after-work commute, there is a stretch of a 3-mi long road where the flow of traffic is continuous with 25 mph limit. At the end of this road is a traffic light intersection where you can sit idle for 5-10 minutes.

So knowing that, I would like to engage the gas engine about halfway through so that the (hybrid) battery would start to charge and thus avoiding the gas engine running at the intersection. However, the EV mode keeps on activating due to the slow 25 mph speed limit (if I rev up the acceleration to take it out of the EV mode, it re-engages EV mode when speed dips below 40). By the time I reach the stop at the intersection, the battery is depleted and gas engine is running at idle, which I hate.

Is there a way to force the vehicle out of EV mode while driving sub-40 mph?

jollick

I experience the same issue but think of it this way, at least the engine is only in an idle state and therefore using very little gas compared to running at a higher RPM to keep you at 25 mph thus using more fuel than when at idle. I hope this make sense.

ElliotB

While you can 'force' the car out of EV mode, you really don't want to. When the engine is at idle, it is using very little gas as Jollick mentioned AND it is charging your traction battery. So while regular cars get 0 MPG while stopped (and is wasting all of its energy), a hybrid is putting energy into its batteries for future use.

To get out of EV mode, you can manually select a low transmission gear, 2 or 3 will generally do it (you may have to apply the throttle a bit). If you want to keep it out of EV mode, keep it in that gear.

IS350atWOT

iTrader: (1)

I have found the EV button to be useless. The car's going to do what it's pre-programmed to do as far as switching in and out of EV. For example, I was going about 25 one day without EV engaged. I was wanting to force EV since I was not going too fast and just put-putting along. So I pressed the EV button to force EV. The display said something to the effect of "unable to switch to EV mode at this time". It later kicked in on it's own, but who knows why it wouldn't at the time. There is no instance I have found where the EV button will kick in EV where the engine wouldn't automatically use EV in the first place. :/

ElliotB

IS350, while I agree the EV button is pretty much useless, it will put the car into EV mode under mild acceleration when the ICE is running and there is sufficient battery power.

IS350atWOT

iTrader: (1)

Cool, I'll play around with it a little more.

jim256

Lots of situations where it won't engage: (all in the manual)


■Situations in which EV drive mode cannot be turned on
It may not be possible to turn EV drive mode on in the following situations. If it cannot
be turned on, a buzzer will sound and a message will be shown on the multi-information
display.
●The temperature of the hybrid system is high.
The vehicle has been left in the sun, driven on a hill, driven at high speeds, etc.
●The temperature of the hybrid system is low.
The vehicle has been left in temperatures lower than about 68°F (20°C) for a long
period of time etc.
●The gasoline engine is warming up.
●The hybrid battery (traction battery) is low.
The remaining battery level indicated in the “Energy Monitor” screen or the multiinformation
display is low. (→P. 110)
●Vehicle speed is about 25 mph (40 km/h) or more.
●The accelerator pedal is depressed firmly.
●The windshield defogger is in use.


And this caution:

■Fuel economy
Your Lexus is designed to achieve the best possible fuel economy during normal
driving (using the gasoline engine and electric motor [traction motor]). Driving in EV
drive mode more than necessary may lower fuel economy.

As I understand it, recovering the battery power spent by selecting EV will be greater than letting it manage itself. I'm not sure I can explain it well, but basically you'll need to burn gas to recharge it, and overall you will suffer. There may be situations where it will not, like extra brake regen or long coasting with regen, but it's really for moving it into the garage, coming home quietly, etc.

IS350atWOT

iTrader: (1)

Yay! It was difficult, but I got it to kick in once. (The ICE was running, but when I pressed EV, it switched over to EV mode.) I felt like I was stacking a house of cards though. Everything had to be just right. LOL.

atoyota

I learned this from the Prius folks on the hypermiling sites who've had an EV mode for a while and it's the only time I've ever tried to use pure EV mode.

In the morning as I'm leaving the garage, I start the car and immediately put the car in EV mode. Assuming I have a sufficient charge in the batteries, this allows me to back out of the garage and go down the street a block or two before the ICE starts up. At that point I am doing 20-30 MPH or so so the ICE is both powering the car and recharging the batteries as I get onto the highway.

As mentioned, once the ICE starts in a cold state, EV mode isn't available, nor will the car run switch automatically to EV mode until the engine warms up sufficiently for the catalytic converter to do its thing.

I am not a hypermiler and the novelty of this has worn off to tell you the truth. I am happy with my combined 38.5 in a large comfortable midsize car. I don't think 38.6 would make me any happier.

jbm79

When I didn't care about FE, I got around 37 mpg. After I got "obsessed" about it, I'm now averaging 41.5 mpg. I've had my car for 4 months now and I am still constantly eyeing the mpg status everyt time I drive (I have the display panel set to display the real-time energy usage...you know, with the arrows pointing to/from engine/battery). Maybe in another 4 months I would not care about it anymore It's like a mini-game to me where I'm trying to better my driving habits and in return yield better FE. Better preoccupation than getting pissed at the traffic, I guess.

So to sum it up, based on personal experience and others' input, the EV button is pretty much useless as it is the car itself that will ultimately decide whether the EV mode will be engaged at any point in time, regardless of battery charge status.

jbm79

You just got lucky...either (1) it was about to switch to EV mode anyway or (2) you unconsciously depressed the accelerator juuuuust a slight bit when you looked down for the EV button, thus engaging the EV mode...LOL

atoyota

Yes I've played the game too. Before the 300h I had a 2009 Camry Hybrid and I did obsess and do everything I could to keep the numbers up. The one and only thing I miss in the 300h is that display in the Camry that would say EXCELLENT if your trip mileage was over 36MPG. It had a graph in the center of the gauges instead of a blue light that actually showed what your MPG was for the trip. It reset each time you turned the engine off. That would really make you obsess, I will say that the 300h does manage the hybrid system better and stays in ev mode longer and engages easier than the 2009 TCH so I guess that is why I am pleased.

Hlee

I park in a garage about six flights up - very slow going to get there. I like the idea of switching to EV mode only for the drive up, but some of the responses on this post seem to suggest that using EV only is always a gas usage loser. Should I or shouldn't I?

Arty101

You can try it both ways, although with 6 levels, it will probably kick in the engine anyway.