Petrol engine in 'idle' mode for a long time after restart

[Rafal K]

Hi, its my first post here so I wanted to greet everyone.

I have my 2022 Corolla TS Hybrid wit 2.0 engine for over 2 years now.
I am quite happy with it but there are some caveats I would like to discuss. One especially.
When I start the car in the morning and begin my journey to work, I see that the hybrid system is reluctant to rev up the petrol engine and despite the engine running, its the electric system moving the car. That is totally understandable. The hybrid system wants to let the oil flowing through petrol engine at low rpm to reduce wear.
What bothers me, is that if I shut down the car for like 5 minutes to go to a store, and start the car again, the same thing happens. The petrol engine starts up but it is not moving the car forward but instead it is idling while the electric drive moves the car. The worst part is, that in this scenario it takes 3-4 times longer for the hybrid system to consider petrol engine ready. Wasting a lot of Battery charge and gas in the same time.
Please consider the following scenario:
In the morning, I start my car, then turn up the cabin temp in order to force the petrol engine on. I sit for 1 minute sending some messages on my phone and then take off. after 300M of idle RPM, the petrol engine spooled up to 2k RPM and I could drive as usual.
After 30 minutes of my regular commute, using pulse and glide technique when possible, I needed to stop at the pharmacy, the car is off for 5 minutes.
When I start the car again, it starts in EV mode. After 100M it fires up the petrol engine but in "idle mode". I drove around 1.5KM, slight uphill, over the span of 5-6 minutes. The car used 2 bars of the Battery (which at this point was down to 3 bars) at which point the car decided it hast to charge it so the RPM gone up and I stood at a red light, @2k RPM smelling my money being thrown out through the exhaust pipe.

If I have to pop to multiple stores on my way back from work it can turn my typical 4,5 l/100km to over 6l/100km on that particular route.

This issue bothers me so much that I started to leave my car on when doing quick errands just taking keys with me. Even though the car stands there the same amount of time, with petrol engine off, after I get back to it, when I step on the gas, the engine starts normally and revs appropriately.

Similarly, when I get trapped  in heavy traffic downhill, just inching forward exclusively in EV mode for up to 10 minutes sometimes, with petrol engine off the whole time, when I finally can step on it, everything is as expected, the engine fires up and revs normally.

Is this maybe some fault with my car ? I don't have any warning indicator lit one the dash and I recently had an yearly service done at the dealer, they didn't have any comments.

Did any of you experience this behavior ? Is there a reason I do not know about, which would justify this?

I'm eagerly awaiting any comment or suggestion.

Regards.
Rafal.

[AndrueC]

My comment is: Let the ECU do what its programmed to do. Your car is the result of over two decades of R&D by Toyota and it knows best.

It is expected that during the colder months it will behave a little differently and that fuel consumption will increase slightly. The ICE needs to be warmed up and so does the cabin. As long as you're not seeing more than a 10% increase in fuel consumption everything is fine. And a 20% increase wouldn't be out of order if you're based in the far north of Europe.

[Rafal K]

@AndrueC Thanks for the reply,
I didn't intend to imply that Toyota engineers under-developed the hybrid system, after all, my car is a 4'th generation hybrid. I just try to understand the reasons behind certain behaviors and also make sure that my particular car is not faulty in some way.

During my first winter with my Toyota hybrid I noticed that my car would not shut down its petrol engine sometimes, even if Battery was at decent charge level and the engine was up to temperature. It kept the engine running even at stand-still. After some research I found out, that intermittent engine operation causes buildup of exhaust contaminants on the catalytic converter and other parts of exhaust purification system and the car needs to get the exhaust up to temp in order to burn the deposits off. After learning that I was able to adjust my driving style and chase better and better economy, after all, I wouldn't buy a hybrid if I wasn't going to try and utilize it to the best of my ability.

I like to understand why and when my car does what it does so I can work around its limitations and quirks. If I have to accept the answer: "It does that because it has to", I will, but if I can find out the actual reason, I have to try.

[Cyker]

We get a lot of posts like this this time of year - In most cases it's because the engine is trying to generate heat for the cabin. When the car is running with the engine off it sheds heat quite quickly, and if the heater is also taking heat from the engine to warm the cabin it can struggle to stay at operating temperature and so fires up.

You can test this by turning off the heating and see if that makes it behave more 'normal', but it's not worth freezing to have higher mpg!

It's the one downside of more efficient cars, as less efficient cars generate so much waste heat you don't notice, but even in my old Mk1 diesel Yaris it'd take aaages for the cold engine indicator light to go out in winter. Being even more energy efficient, hybrids and EVs get affected the worst because they have the least amount of wasted heat so have to 'waste' energy to generate it especially.

 

[sportse]

There’s a lot of information around about the first few generations of the Prius, I found it really useful to understand the hybrid system. there are some good diagrams and videos too  

there are different modes for warmup/etc that the car runs depending on many variables. 
 

the newer cars have a more advanced system, but it’s based on the original so much of the information is similar. 

[TonyHSD]

Perfectly normal behaviour and absolutely every Toyota hybrid works the same. You don’t waste petrol at all and in your circumstances if you were driving a petrol only or diesel from 6.5/100 you will be looking at 10/100 Ltr/100km. , still the hybrid is more efficient. 
Your car starts and runs the engine to propel the car , charge or discharge the batteries, both hybrid and the small one and to supply heat to the cabin. So there is always a reason why the engine is on , usually one of the above or combination of two or more. 
If you after super short trips most efficient cars are bevs, but you know they doesn’t fit everyone’s  lifestyle, likes or ability to charge. 
 

[Rafal K]

Thanks for all the answers.
Unfortunately my particular problem/question is a little bit deeper. I am not worried by the petrol engine being on, I fully understand the need for heat and power which require it being on when the car decides it needs it. My problem is that despite of the petrol engine being on, the car doesn't use it for propelling the car forward, it just idles. Pushing the gas pedal causes no change in rpm (~@1k) and the car is driving basically on electric power only.
As I described in the original post, I understand, why my car might want to idle the petrol engine when the engine is cold, but after a short power-off, with the engine still warm, Battery over half capacity I don't get it. Especially considering that in this "restart" scenario this "idle" period is many times longer than with the car being cold in the morning...

[Tomv]

I think it has to do something with the heating, imho it’s is more efficient to use the engine to directly heat the cabin , then use engine to charge Battery and then use electricity to heat the cabin, since with each additional step there are more losses. 

[Stopeter44]

56 minutes ago, Rafal K said:

My problem is that despite of the petrol engine being on, the car doesn't use it for propelling the car forward, it just idles.

Are you over thinking ? The engine will run more in cool/cold weather, and there's a pattern between Summer and Winter use, where you'll have about 1l/100km more fuel consumption in winter. On very short trips in cool weather I turn the AC/Heat off. 

[Rafal K]

49 minutes ago, Stopeter44 said:

Are you over thinking ? The engine will run more in cool/cold weather, and there's a pattern between Summer and Winter use, where you'll have about 1l/100km more fuel consumption in winter. On very short trips in cool weather I turn the AC/Heat off. 

Sure, its a minor thing. I also don't use heating on most trips. I even strategically turn the heating on on a fast section of my commute to warm up the cabin and shut it off on the last 3km downhill stretch through the city so I can do it on electric power only.

Maybe there is actually something wrong with my car and no one here experienced such behavior in their car. Everyone seems to think that I am bothered by the petrol engine running more in cold weather. I bet that you had to explain that dozens of times but that is not the issue here. I fully understand why that happens. The issue, again, is that after a short power-off (and I mean short, even 5 minutes), the car seems to be in "engine warming up mode" and for much longer than after completely cold start in the morning.

• cold weather = more petrol engine usage | OK
• cold weather = higher fuel usage | OK
• cabin heat set above ambient = petrol engine has to be on to provide the heat | OK
• cold start = petrol engine idles in order to distribute the oil and refuses to rev up even if gas pedal is pressed causing electric motor to handle the driving | OK
• restart after short power-off = petrol engine idles even in motion and the car refuses to use use petrol engine even with gas pedal pressed quite far* and all wheel power comes from the Battery. Identical to cold start scenario but for way longer and, again, on a warm engine. | why ?

*If I floor the gas pedal I can force the petrol engine to rev up past idle RPM, but that seems like forcing an abnormal behavior.