RAV4 Dynamic Plug In Hybrid engine starts up

[jamiem1987]

Hi all just an observation I was not expecting with my 2021 phev rav4 - even with full or good charge (eg 40/30 miles ev mode range remaining) in ev mode i’m noticing the engine starting up once a twice on motorway journeys. Not a big deal but annoying as my previous volvo didn’t do this (also phev). - it seems to happen when the cruise control using dynamic radar applies the brakes fairly hard to slow for the car in front, the car seems to like using engine braking which is fine but then the engine runs for 5 mins doing nothing until it warms up and obviously wasting fuel doing so.

Anyone else noticed the same and have a workaround such as driving in eco mode etc?

[ernieb]

Hard braking going downhill will start the ICE, engine braking of some sort? Very hard acceleration will start the ICE. However, more likely is the car management systems deciding that the ICE has not been run for some time and turns it on to circulate the fuel/oil etc. I've found this happen very now and again.

[jamiem1987]

Just to add to this it's definitely the dynamic cruise on braking that fires up the engine, I did some tests today on the motorway and when a heavier than normal amount of stopping is needed under cruise it brakes through the engine, would prefer it not to but I guess they're using the same software as the hybrid model which does the same, the difference is when it does it in the plug in the engine is cold so it runs it through the warm up cycle which can take 3 to 5 minutes burning fuel. Once it's done this once if it needs to brake again the engine switches straight off after. Obviously in the hybrid which is mainly engine driven the engine would just click off. Now I know I can simply do the heavier braking bits myself via the pedal (which doesn't fire up the engine)!

[ernieb]

Whilst I like the convenience of using the ACC I’ve found on longer trips it’s much more economical to use the manual controls. So now I only use ACC mainly when the traffic is slow moving and constantly braking/stopping. On the open road the ACC accelerates and brakes too hard, I can obviously anticipate the traffic more easily and ease off the throttle or allow the regeneration braking to slow me down.

[nlee]

On 9/13/2023 at 11:07 PM, jamiem1987 said:

Hi all just an observation I was not expecting with my 2021 phev rav4 - even with full or good charge (eg 40/30 miles ev mode range remaining) in ev mode i’m noticing the engine starting up once a twice on motorway journeys. Not a big deal but annoying as my previous volvo didn’t do this (also phev). - it seems to happen when the cruise control using dynamic radar applies the brakes fairly hard to slow for the car in front, the car seems to like using engine braking which is fine but then the engine runs for 5 mins doing nothing until it warms up and obviously wasting fuel doing so.

Anyone else noticed the same and have a workaround such as driving in eco mode etc?

Are you driving in EV or Auto EV/HEV? Not tried it myself but the manual blurb implies the Auto EV/HEV might use the engine more. I drove in EV and have never experienced the engine kicking in on ACC breaking.