Hey everyone.

I figured I'd start a thread for all of us driving the 450h version to share our experience about driving in cold weather.

I live in Edmonton Alberta where the temperature could be in the sub-zero (American) for months at a time.

one thing I wish I had known before buying the car is that in that temperature range the EV motor barely if ever kicks in. The same thing that makes this car perfect for me in more temperature weather is what makes it the worst car in freezing temperatures.

What I mean: I work from home. Do very little mileage and charge every night. So I got the car in July and drove 4000km before having to put gas in the car. Now it's completely flipped. I never drive the car long enough for EV mode to kick in so I'm basically driving a regular NX hauling a 500lbs battery, so my mileage is dismal.

I just thought I would share my experience and I'd also like to know what some of you fellow 450h owners do to maximize efficiency in cold weather.

Cheers!

 

Here in my part of Ontario the temperatures lately have been around -5° C and I can use EV mode all the time, but available km drops, especially when using the heat pump to warm the cabin. Have you tried pre-conditioning the car while still plugged in so the cabin is warm and the windows frost free and then only using the electric seat heaters and heated steering wheel for warmth to see if traction motors will work? I don’t think the heat pump will provide heat at -20 ° C so the ICE engine needs to run to provide cabin heat.

 

If I'm understanding correctly you can't even drive a few miles in EV only mode? Not insanely cold in Edmonton these days but still cold about -25C at night.

 

What I've experienced is that when the temp gets around 5F (-15C) or colder the ICE kicks in even if I'm in EV mode unless I turn off the climate system. I'm assuming that the software in Lexus/Toyota is trying to optimize the battery and taking advantage the ICE to help warm the cabin when it's bitter cold.

 

Sounds like this procedure should be at the top of all 450h+ owners of things to do when temps drop to below freezing. Preheat while you're still plugged in and save some fuel.

 

Everything you said is spot on. Here are my observations. The cut off is -12 c. Above that temperature I run in EV mode, no problem, as you've mentioned.

My Garage isn't heated but is insulated, so the temperature sits at around -7. I usually remote start the car and it starts in EV until the thermostat realizes it's below-12 and the engine kicks in. So I went for a longer drive yesterday (1 hour) after about 25 minutes of driving my car started behaving exactly like the hybrid model, where EV mode would kick in when optimal. I ended up with an average of 6.4 L/100km which is not bad at all because my hybrid would average around 7L/100km in the winter. My understanding is that pre conditioning requires the schedule and I have no set schedule

The issue with my use case is that I rarely drive for more than 15 -20 minutes at at time.

Another observations which I learned with my hybrid is that 21 degrees is the cut off. If you stay at and under that cabin temperature, EV mode will engage more often. And finally, to answer your last point, yes, if I turn off the heat, the car goes into EV mode, but 1- it's not comfortable and 2- the windows fog up over time, so you then have to turn on defrost erasing all of tha gains.

Anyway, thank you for your feedback.

 

You're exactly right. Anything below -12 kicks you out of EV. It took about 20-25 minutes of driving to see EV engage sporadically at -26. My guess would be that it would engage sooner at -15 and later at minus 35. So my short drives to the gym, for errands and such are usually ICE only. That means the regular non-turbo NX engine lugging an extra 3 people at all time, due to the electric battery weight slightly above 400 lbs. So I end up at around 11 L/100k.

 

From my experience, it doesn't do much. Yes the cabin is warm from the jump, but as soon as the car realizes the temperatures the engine kicks in. I say you drive in EV for like 2 minutes, max.

 

I have posted this behaviour in my ownership videos a few years back. Think of it with the 350h, the gas engine would be exactly the same, the gas engine will run more to warm up the cabin. There is no difference between the 450h+ and the 350h in terms of operations in cold weather. MPG / L/100km will take a toll across the board and not just the 450h+. In fact, I have seen cases where the gas engine will turn off even under -12C, and that is when the cabin is warm enough. The main reason why the gas engine is on is to ensure you are warm fast enough as the heat pump is not effective enough under the -12C threshold.

Before you leave, you could remote start the car to warm it up for a max of 20 minutes while it's still plugged in that way it will still precondition the cabin and in fact, recharge your 12V battery as well. But at that cold temps, it will recharge even if you drive 5-10 mins. The goal of the PHEV is not to not use gas or the gas engine, but it would help reduce the consumption of gas. Even if you can drive on EV for 2 minutes like 2-3km out of a 10 km drive, you have driven a 7km drive with the gas engine on - vs a 10km drive on the 350 or 350h.

 

Just a thought:

I know it's of no real consequence to anyone with a 450h+ in most situations, but the engineers would have run through all the possible what if's and maybe a) if the coolant is too lean as in someone topped up a leaking system with water and diluted the mixture. Then the coolant may freeze or come close to freezing and begin damaging cooling components at a warmer temp then if not diluted too much. Or b) if the coolant hasn't been changed at the specified interval and has become ineffective and will freeze at a higher temp. So they walked that back a bit to have a safe buffer and now these temps where the ICE comes on starts to make some sense. Plus maybe the viscosity gets thicker too when it's cold impacting it's flow.

Google says: Typical antifreeze (ethylene glycol) is generally rated to protect engines down to -34 F or -37 C while protection usually fails or begins to solidify around -36 F or -38 C . I have no idea what Toyota's pink coolant is composed of or what it's protection temp limit is.

 

While plugged in you can set a 'one-time' precondition schedule. This should work if the temperature in the garage is above -12 deg C.

I usually do this about 30 minutes before heading out as this will operate for thirty minutes instead of the twenty minutes with remote start.

The climate settings for this schedule are different than the settings that you have set for remote start.

 

So am I to understand that the 450h+ will use heat from the ICE if the ICE is running in Hybrid Mode? I live in a very mild climate so I haven't used the heater much.

Mostly I have the seats and steering wheel on auto and that seems to warm the us until the sun warms the cabin.

I thought it only used the heat pump as I rarely drive in Hybrid mode because gas is expensive in California and electricity is free from the Solar Array on our roof at home.

 

That is correct - it will use the ICE to heat the cabin - you will notice the cabin heats up much faster with hybrid mode.

 

I am operating under the understanding that the 450 will not draw power from the wall once charging is complete. If I were to Remote Start to warm the car in the garage, I would not expect charging to supplant the power if it is still plugged in from an earlier charging session. Correct?

My bigger concern is that the manual claims that below -24 degrees F, the battery and thus the ICE may not not start, since the battery starts the engine. I haven't experienced this, yet. Global warming has mitigated these concerns.

 

1. When the car is remote started or you use the climate conditioning setting, the traction battery will power the heat pump, heated seats, defrosters, and heated steering wheel . When AC charging cable is plugged in the traction battery will start to charge and it will also charge the 12 volt battery.

If you start the car while sitting in the driver's seat while the car is plugged in with the AC charging cable you will get a message asking if you want to run the "My Room" mode which allows the use of the climate settings, infotainment, etc using the AC power (p 84 of my manual.)

2. The 12 volt battery initiates the Ready mode of the car.

From p 62 of my manual: (I'm in Canada)
■ Traction battery heater
When the outside temperature is low and the AC charging cable is connected to the vehicle, this function automatically warms the hybrid battery (traction battery) until it reaches or exceeds a certain temperature. Traction battery heater will operate when the [Battery warming] of the [Charging] on the center display is on.

■ Traction battery warming control (Alaska and Canada only)
This control operates after the AC charging cable remains connected to the vehicle for 3 days and traction battery heater automatically stops. It automatically insulates the hybrid battery (traction battery) in extremely low temperatures."