Revs in Toyota Corolla Fielder Hybrid

[PixiePie]

Hi all,

I got my first hybrid car and it's a Corolla Fielder 1.5 2016.

The revs don't go up and down when pressing accelerator they just go up (seems like the car is not going up or down in gears) you can hear the engine roaring for different gear. Unless I release my foot from the pedal it will just continue in 5000/6000 revs.

Has anyone came across this before? And is it normal for hybrid car to do that, or should I have mechanic have a look at it?

I tried looking up videos on YouTube but didn't come across anything on this topic.

[FROSTYBALLS]

Moved to the Corolla forum.

[AndrueC]

It's perfectly normal for a CVT equipped vehicle and 'the way it should be' for all vehicles, if only they could..

A CVT offers an unlimited number of gear ratios (within a range) so the engine can be kept at the ideal RPM for whatever it is the driver is asking it to do.

RPMs rising/falling are an unfortunate consequence of the limited choice of gear ratios available on most vehicles. A vehicle equipped with a conventional gearbox has to choose between 2nd (too high RPMs) or 3rd (too low RPMs). A vehicle equipped with a CVT can choose 2.34 or 2.45 or anything else in between 2 and 3.

To be strictly accurate the Corolla doesn't have a 'CVT gearbox' but in practical terms it amounts to the same thing. The ECU will choose the best RPMs for the ICE and fine tune them as it goes. Under steady acceleration that might sticking to the same RPM or it might mean gradually increasing the RPM.

It might even mean reducing the RPM although I've never noticed that happen on the Corolla. My previous car was a Honda Jazz equipped with an actual 'CVT gearbox' If you accelerated hard then eased off a bit you could keep the Jazz accelerating while the RPMs were dropping.

It's best not to worry about it. Just accept that your Corolla's ECU can operate the ICE at whatever RPM is best for efficiency (or torque if you are pushing it) and let it do its thing. The relationship between road speed, load and RPM is much more flexible than with a conventional gearbox. That's why all forms of CVT are better.

 

[AndrueC]

Oh and I forgot to add: The hybrid aspect of the Corolla complicates things further. The car can choose to improve ICE efficiency by having the electric motor do some of the work. This can result in lower RPMs for the same road speed.

Perhaps more bizarrely the car can do the opposite. It can put additional load on the ICE by getting it to charge the Battery. This might seem silly but the additional load might allow the ECU to operate the ICE more efficiently. In this mode you're burning more petrol than you need to keep the vehicle moving but you're getting more energy out of the fuel you burn - the surplus energy is stored in the Battery to be used later.

It all comes down to the same thing: RPMs are hard to predict and hard to understand with a CVT and even more so with a hybrid. There's an argument to be made that Toyota shouldn't have bothered with a rev counter because it doesn't tell the driver anything useful and the driver has no control over them either.

[2badmice]

doesn't driving style also come into it?  If you're heavy footed for instance?

[Tech429]

On 6/26/2022 at 8:06 PM, AndrueC said:

There's an argument to be made that Toyota shouldn't have bothered with a rev counter because it doesn't tell the driver anything useful and the driver has no control over them either.

I feel the same.

The Rev counter is useless really - better to have had a power indicator type rev dial instead.

[Tech429]

On 7/3/2022 at 8:04 AM, 2badmice said:

doesn't driving style also come into it?  If you're heavy footed for instance?

Very true!

If you are going uphill then it is reasonable for you to put more foot down and power.  But on the flat you can just about coast slightly.

Amazingly i have been on the motorway doing 72 and the EV has come on for about 1/4 mile or so (if on flat or slight down hill) - then ICE comes back on for a few miles then EV again.  If the engine does not need ICE to work it will allow for EV mode to work instead.

[PixiePie]

Thanks guys! This is really helpful, I was about to go to have it looked at by mechanic cause I don't know anything about the EV and ICE.

 

 

[TonyHSD]

This car has most likely the Yaris drive train if it’s 1.5 hybrid. It’s not very powerful and on open roads or motorways it is normal to maintain high rpm when  driving fast or loaded, going uphill or when overtaking. 👍