Maybe it's because it's getting warmer outside, the window is open a little, I'm not listening to the radio, or whatever, but it seems that I hear that sound where the timing is retarded ie, weak power, RPMs go up. This is when the engine is warm. Also, sometimes I see the engine rpms go way low, the EV light isn't on, but the SOC% is going down. The engine is not cold at this point. I know, not very scientific, but I didn't notice this stuff when it was cold out. Thoughts? Gen3: Gen3 warming up stages | PriusChat
Cold air drawn in and used to make ICE power, all things being the same, will produce more specific output than warm air. Thing is, things will not be the same around those two parameters... and if so, not for very long. I've noticed w\ my 5G HEV... warmup is longer at 68F ambient (according to the temp display in the dash, who knows how accurate it is; haven't checked after it) than 72. My way out of my gated comm'y's a certain fixed distance, up- and downhill slightly. When the car was new, the warmup phase of ICE firing would last until almost exactly when I'd come upon a speed bump (~80 - 85m). This did not vary whether ambient was low 70s or high 60s -- in the first year and half. Now w\ 20K, it needs another 30m or so (the next bump) before the ICE shuts down, warmed. These are some of those mitigating factors mentioned earlier. Are your plug electrodes beginning to wear? Are they torqued properly? Is your emissions control system sending bad data to the PCU, because you top off your fuel tank with multiple clicks at the nozzle (don't do this, causes raw fuel to enter the system and flood the charcoal canister... which then cannot store fuel vapours and will not supply the ICE w\ proper richness it expects). Is your air filter dirty? Is your oil spent and full of water? All these things can affect ICE performance more when warm than cold... and will cause the PCU to make adjustments accordingly, biasing emissions over fuel economy. Priuses have Atkinson-cycle ICEs, so a lot more sensitive to conditions than Otto-cycle. Which is why only a few automakers use Atkinson-cycle ICEs on their own, as not part of a hybrid drivetrain. Honda's current Civic has a base model LX with a 2.0L naturally-aspirated one... and it's 16bhp weaker than the 1.5L turbo it replaces -- not to mention will not like being driven hard. The Old Man is truly dead
