More EV Auto Experimenting

So if I understand you correctly if I am going to take a trip that involves some highway driving I should precondition the ICE by running in HV mode briefly to start a warmup cycle and then run in EV AUTO from then on?

 

I have not used EV Auto much except for the first few months after purchasing the car for trying out different modes. But for during the small samples of my trials, under my normal driving conditions, what you wrote was true.

I don't have any highway segment on my commute. The top speed limit is 45 mph. I may get up to 60 mph on the down hill portion, but never accelerating at that speed on my daily commute. Some uphills may benefit from HV, but under normal conditions with EV AUTO, it did not fire ICE. This summer, I have been manually switching HV/EV to manipulate more HV on steep uphills, but this usually result in less overall mpg for return of increased miles/kWh.

 

My commute is 38 miles one way and 95% of that is at freeway speeds (when not stuck in traffic).

To get to the on ramp, I leave the car in EV mode.

Once the light is about to turn green, I push the HV/EV button to fire the ICE and have it “preconditioned” for 2 large hills I have to traverse to work.

Once up to 65 mph and moving with traffic, I push the EV button (which puts it in EV Auto) and ride that out until the first hill. At the first hill, HV/EV is pushed and I use the ICE to climb that hill. Once at the top, EV button is pushed and back into EV Auto until hill #2 and repeat.

I usually end up with 32 miles of EV driving for my 38 mile one way, so not too bad.

 

Here’s a shot of the energy consumption driving this way:



Not too bad.

 

Any comparison to the number if you drove all EV until it runs out then switch to HV (or if it does not run out then 100% EV). Also, comparison on MPG difference in between those two cases?

In my case, I have 36miles (18miles one way) daily commute. During summer time, I can drive most of 36 miles on EV mode. Sometimes I can make back to home completely in EV, but most often EV range runs out a few miles to few hundred feet before reaching home. If I do not switch HV/EV, I usually ends up with 199.9mpg (even with a short HV run included) but can only get 4.6-5.2miles/kWh on EV. If I use HV/EV switch to drive HV on steep uphills, I end up with 160-199mpg, but can get 7.4-8.7miles/kWh. With switching HV/EV, I use more gas and have some EV range left when I get home.

 

If EV Auto is the mode for best overall energy consumption, then that would only be true in the case of a long trip. That is, if your trip will fit entirely into the EV range, then pure-EV mode is definitely more efficient.

I haven’t used EV Auto, but I gather the underlying concept behind it is to increase miles-per-charge by kicking in the ICE on operations that would otherwise burn down the battery quickly.

I personally would be more interested in the kinda-sorta opposite mode — a mode whose underlying goal is to burn down the battery as needed in order to maximize ICE efficiency.

Ordinary hybrid mode, in part:
1. Long-term, strives to hold the battery level roughly where it was when you entered hybrid mode,
2. Where realistic, strives to avoid kicking in the ICE unless it can operate it at close to peak efficiency, and
3. In cases where it’s more efficient for the ICE to just directly drive the wheels, does so.

This non-existent-oh-well mode would take #2 above to the max, but not necessarily do #1 and #3. That is, it would run the ICE when and only when it can do so at close to optimal efficiency (only when it’s actually needed, of course), and burn down the battery to “pick up the slack,” so to speak. That, until the battery burns down to the EV-HV threshold, which point it goes to plain ‘old HV mode.

 

No comparison in other driving methods. I do t like the ICE to kick in when I’m traveling 70 mph and it’s stone cold.

The GOM states I have 34.2 miles this morning, and based on the result I probably got 33 miles.

Others can experiment while I’ll give my experience as the ICE can be a delicate beast that I don’t want to have any issues with it. I’ll baby it as much as I can .

 

I understand. In my case, I hate the ICE to kick in only a very short distance before reaching home. Often, it dose not even have a time to complete the warm-up cycle, then I have to shut it down not fully warmed up. With manual HV/EV switch, I usually start HV a few miles before reaching to the bottom of the uphill to complete the warm-up cycle then use ICE to climb up. With EV AUTO, ICE never come on until EV range is exhausted as I stated above, so that mode is useless for me. I also try to keep the ICE warm enough once it completes the warm-up cycle, so that I don't have to do multiple warm-up cycles on a single commuting trip.

 

I've been using EV Auto quite a bit. It always warms up the ICE before using it. I can tell that even though the ice is on, the propelling force comes from the battery for a while. I have the display showing instant mpg/kwh. When the engine kicks on, the display changes to MPG, but the MPGs stay at max until the engine warms up.

 

Between 70 and 100F. It kicks on around 70mph or if I floor it for a while on the on-ramp (starts warming up). Yes, EV Auto.

 

Is it really bad for the ICE engine when switching from EV to HV in highway speeds (65mph or above)?
On my work commute, 51 miles one way, I start EV from home up to the highway (5 miles). Then when my speed is around 65ish, I switched to HV and run it for 5 miles. This 5 miles are pretty much 90% uphill.
Then I switch to EV again for the rest of my trip. Sometimes if there are traffic, I can get to work in EV, sometimes it runs out of charge within 1-2 miles to my destination.

Thank you.

 

I really don't think it's bad at all. The car is running almost all on EV while the engine warms up as you can see by the mpg bar next to the speedometer if you have that turned on.

 

I have noticed that too. If the engine is cold it will run in EV mode until the battery is empty, unless you floor the accelerator. If it is warm it will come on going up hills. I think colder weather and cruise control use make the engine more likely to come on in EV auto, but I can't confirm.

I also noticed, with the engine warmed up if I floor it from a stop it will still accelerate in EV mode up to around 45mph, and the engine might kick in after that. I have not tested what it does flooring it with the engine cold, and I don't really want to find out.

It's not bad for it. The car controls the engine speed to idle while it's warming up.

It might be bad for it if the engine is not warmed up yet and you need to accelerate quickly. Then the engine might get involved before it is fully warmed up. For example if you switch to HV mode just before merging onto the highway, or before going up a hill, or floor it in EV Auto where it supposedly can turn on the engine for additional power. And it's more likely to be a problem in cold weather when the oil is colder and engine takes longer to warm up. In warm weather, even just a few seconds of warm-up is probably enough to prevent excessive wear on the engine.

 

After switching to HV, I try to stay on the blue line on the ECO accelerator guide

 

Where is this display? I'm new to the Prime, and can't find it (the only one I'm able to find so far is on the "history" tab, and I get a bar on the right side.

Thanks!

 

you have to enable an extended MFD and it pops up on the right of the leftmost part of the dials