My prime doesn't have much power when not in the EV mode

I'm skeptical of this dealer explanation. The Prime should have the same engine and engine power as the non-Prime, though the car itself is a bit heavier.

The Prime should also have a small portion of its battery reserved for HV operation just like the non-Prime. But even the non-Prime can run its battery out and feel sluggish until it gets some recharge. Could you have run into this equivalent situation?

 

Your dealer is highly confused. Both cars have the same engine other than the sprague clutch in the Prime that allows faster EV speeds without over revving the electric motors. And, no, just because you have run out of EV range does NOT mean there is no juice available in the battery. It's simply running just like any other Prius.

As Tideland correctly pointed out, it just feels a little sluggish in HV mode because MG2 isn't providing as much instant torque as it does in EV mode.

 

Sprague clutch sound very similar to a bike freehub.

 

Try this, When you are driving it using the ICE, put your vehicle into 'PWR' mode and see if it handles differently. Compare that to 'ECO' mode.

In my 2017 prime the handling with 'PWR' as compared to 'ECO' is remarkably different.

Mash the accelerator to the floorboard in each mode and see if it accelerates differently.

Some posters will want to argue that this is impossible. Try it, and tell us what you find.

In my area, some roads are very hilly. My wife complained that she was barely able to top some of the hills. But when we put it in 'PWR' mode and set cruise control, it takes the hills at 65mph with no slowing.

 

is this behavior new, or is the car new to you? it sounds normal, as stated above.

 

I have a 2017 Prime that is new to me from three weeks ago. Took it this weekend for a round trip Ottawa Toronto. Even with the battery at "0%", there is still batterie charge left in the pack for helping the engine when accelerating in Hybrid mode. I had no trouble passing cars on the two way roads I took. Mind you, it's not comparable to my Model 3 where I have to monitor my speed not to overspeed (too much) but I was never affraid of running out of time to pass.

If you have a OBD2 adapter, try pairing it to Hybrid Assistant (Android app) to see what's going on with the motors, engine and battery.

 

Ngan, the service writer you spoke with doesn't know what they're talking about. They are a commission salesman for service, not a well trained technical expert.

Do try the accelerator pedal mode in PWR. It makes a difference. It determines how much motor or engine output you get for a given amount of push of your right foot. We have to remember here that Toyota's wisdom gave us two completely different things called "Mode." The propulsion modes are EV, EV Auto, and HV. The accelerator pedal modes are ECO, Normal, and PWR. (We use Normal around town and PWR on the freeway for more giddy-up.)

SPRAG clutch, a one-way clutch, although overrunning clutch might be a more accurate description in this usage.
Sprag Clutch, Overrunning Clutch, Holdbacks, Backstops | Formsprag Clutch

 

Welcome..

Your power-train warranty is 5 years 60K miles; so if there is something wrong - it's covered. If you don't believe your dealer; take it to another one; you have a few to chose from in the Sacramento region. Doesn't hurt to get a second opinion; especially since your description from your current dealer; had some factual errors in them. It may have been a simple misunderstanding.
If there isn't anything wrong, try running the car in 'normal' or 'power' mode; that should get you the performance you want - but a small ding to your gas mileage ( as stated in post #6). It still won't perform as well as EV mode; but it'll get you close.
Whenever I jump onto the highway; I manually switch to HV - reserve EV mode for city streets, stop & go traffic. The car handles much better in EV; during those situations. Normal- or Power- mode while traveling in the Sierras; otherwise you'll really have to mash that accelerate peddle - It's just how this car works....

Hope this helps

 

Similar idea but there's more to it. Watch the whole video for a brief explanation of your transaxle, but here's the point where Professor Kelly talks about the sprague clutch.

 

If there aren’t any codes, no dealer will do anything

 

That's a little like switching from dark to dry. The two settings have nothing to do with each other. While in EV mode, the car can be running in ECO, Normal, or PWR. And all three settings are available in HV mode as well. See post #9 quoted below. It can switch automatically from EV to HV.

I suggest spending some time in the owner's manual. It's one of your best friends if you own a Prius Prime.

 

One more thing on the difference in feel. Because of the sprague clutch, MG1 can help MG2 power the car. That gives it a little more torque.

 

They’re likely right. I’ve read this here before; the Prius Prime has the same engine; there might be slight differences in the transaxle, that’s it. The Prius Prime is heavier, that’s a factor.

Owners have reported here it’s a little sluggish in hybrid mode. But that’s normal. the dealership can’t help with that, and their advice is sound.

 

You're right, there is a difference in the final gear ratio between the Prius and the Prime. Posted above but set to a different time offset which explains it:

 

even my pip is more sluggish in hv mode, that's the nature of electric motor instant torque

 

The Prime is definitely more sluggish in HV mode than EV mode. This is due to that Sprague clutch and the nature of the planetary gear set. In EV mode the car has more torque due to the two electric motors working together but in HV mode the engine torque is split between MG1 and MG2 (If memory serves at a 30/70 ratio). The upshot is that in HV mode the car has less torque than in EV mode. In my 2018 the only real effect of PWR mode is that the dash turns red and the engine is louder. Ok, so there's a bit more power but it isn't that dramatic.

 

SPRAG not sprague

Please explain. In EV mode the motors are, of course, powering the drive. In HV mode the engine, and sometimes a motor, is powering the drive. The engine power (not just torque) goes through the planetary transmission to drive the car. What does it mean, "...in HV mode the engine torque is split between MG1 and MG2...."

Power gets work done. Power is force over a distance. Torque is merely a twisting force. (As an example, all the industrial power sources I've seen list the prime mover's output...diesel or turbine...in horsepower or kilowatts, and the torque is never listed--nobody cares. Kilowatts are used even for mechanical power because it is a universal measure worldwide; horsepower units vary depending on the usage and region of the world, e.g. shaft horsepower is different from brake horsepower for the same usage. Imperial hp = 745.7 watts; metric hp = 735.5 watts.) (An electric motor with a locked rotor produces zero work but infinite torque...until the motor goes up in a blue flash and cloud of black smoke.)

Here's a spec from a medium speed MAN diesel engine...V-14, 21,500 hp (expressed as kW) @ 500 rpm, no mention of torque.