Prius Prime Plus in my hands

It turns out the indicated speed error brings the 28 mph within 1 mph of the true speed, 25 mph. The car shows faster than it is actually going.

Fortunately, my neighborhood has one of those radar, speed measuring signs. If I approach it in the BMW i3-REx (similar error), it shows I am doing 23 mph, not the indicated 25 mph.

Bob Wilson

 

The MPG vs mph chart is fixed. I checked the BMW i3-REx against the radar reporting speed sign: 28 mph indicated is 26 mph radar reported true.

Bob Wilson

 

We had a cold snap come through so it will be a day or so before temperatures are back to 'standard day' range (i.e., lower 60s.)

I will update the chart to include the Gen-3 metrics and Prime data points. I've got 28 mph, 105.5 MPG and 60-65 mph, 55.7 MPG. I need two more data points: a 40-45 and 75 mph.

Right now, I don't have an SOC metric. If I can get my Scangauge back and/or use some of the other OBD scanners, read out the SOC, I will do some hill climb and descent tests.

Bob Wilson

 

Too cold, 55F, and windy, 20 mph wind gusts, so I went for a maximum hill climb. Only 89-90 mph at crest, the residual battery icon suggests the default SOC rests about the same as our former Gen-3 and Gen-1 relative to the 525ft (160m) hill.

The descent from a stop on the grade suggested about 45 mph we had reached close to stasis. But at higher speeds, the car started taking off. This is expected as the charging power stays constant but the kinetic energy increases as the square of the velocity. This car is a physics lab on wheels.

Had more speed bumps and that new, rear suspension really smoothed them out.

Found the tire valve caps on too tight and bought a leatherman multi-tool. Forgot to buy the tire plug kit.

Cold soak tonight for roll-down in the morning.

Bob Wilson

 

Thanks for the tip on SOC. I'll be testing it shortly. But more details about my hill tests.

• Bottom - 34.526203 N, -86.589309 W
• Crest - 34.508448 N, -86.603740 W

At the base, I wait for traffic to pass and hold off until I see the next group of cars approaching. I then pull onto the roadway; stop; and mash the accelerator to the crest where I note the speed. The ~90 mph is about 2-3 mph slower than what I've seen in our former Gen-1 and Gen-3. I suspect the battery weight is the problem (of course I could lose some weight.)

On the descent, I wait on the side of the road until traffic has passed and no more is seen approaching. I pull onto the grade and with the car in "D", begin the descent. The car "creep" gets the car started and speed begins to build. What I found more distinct was at ~45 mph, the rate of speed increase seemed to Peter out. It may have happened in the past but I noticed it this time. IMHO the greater depth of charge means the Prime can still put a maximum charge into the battery that the smaller traction batteries could not take. Once the speed reached 50 mph, the car smoothly descended faster and faster which I attribute to the kinetic energy increase ... same drag force over a faster, longer distance. In the former Gen-1 and Gen-3, I would have to use "B" or the brake to slow the car down for the last curve. Although a little brisk, exiting the last curve at 75 mph was 'keeping up with traffic.'

Bob Wilson

 

In defense of the white tray between the driver and passenger seat, our Prime came with a black 'tray'. So Saturday evening, I came home and left my black cell phone on the tray. Had it been white, I might have seen the outline and maybe not had to get dressed to go out in the middle of the night to fetch the phone.

Bob Wilson

 

As long as everyone is careful to identify the source, we should all be good to go. Personally I like the idea of using the built-in metric since at $150-200, a Scangauge is a little 'over the top' for many.

Bob Wilson