Prius Prime Plus in my hands

Cold-soak, temperature 46F, I used EV to reach a route to run safely at 40 mph:

• first 0.6 miles - car dips into EV to sustain speed, nice!
• 0.6 - 2.1 miles - car warms up engine
• 2.1 - 5.0 miles - warmed up car, excellent 50 MPG
• 1.4, 2.7, 4.7 miles - three complete stops, need a better route
• 4.1-4.3 miles - traffic slow-down
• route is not a level flat as I would prefer

The total route is 10 miles (indicated), 10.2 miles Goggle (true):


I've only plotted the first 5 miles.


Raw Data:

	miles	MPG	mph	SOC%
1	0.0	0.0	0	0.98
2	0.1	28.6	37	0.98
3	0.2	43.0	40	0.97
4	0.3	50.9	40	0.97
5	0.4	50.9	40	0.97
6	0.5	55.7	40	0.96
7	0.6	59.0	40	0.96
8	0.7	51.4	40	0.96
9	0.8	47.3	40	0.96
10	0.9	45.0	39	0.96
11	1.0	41.0	41	0.96
12	1.1	42.0	40	0.97
13	1.2	42.5	40	0.97
14	1.3	42.9	40	0.97
15	1.4	41.7	28	0.98
16	1.5	39.0	39	0.98
17	1.6	38.3	40	0.98
18	1.7	36.6	41	0.98
19	1.8	35.8	40	0.99
20	1.9	35.8	40	0.99
21	2.0	35.8	40	0.99
22	2.1	37.8	40	0.99
23	2.2	39.8	39	0.99
24	2.3	41.8	39	0.98
25	2.4	43.8	39	0.98
26	2.5	45.7	40	0.97
27	2.6	47.8	40	0.97
28	2.7	50.6	7	0.97
29	2.8	47.1	36	0.97
30	2.9	45.2	39	0.97
31	3.0	45.2	39	0.97
32	3.1	43.7	40	0.97
33	3.2	44.0	39	0.98
34	3.3	45.5	39	0.98
35	3.4	47.0	39	0.98
36	3.5	48.5	39	0.97
37	3.6	48.1	39	0.97
38	3.7	46.7	40	0.97
39	3.8	47.4	39	0.97
40	3.9	48.7	38	0.97
41	4.0	50.1	39	0.97
42	4.1	51.4	35	0.97
43	4.2	51.6	33	0.97
44	4.3	49.5	38	0.97
45	4.4	50.0	39	0.97
46	4.5	51.2	40	0.96
47	4.6	52.5	40	0.96
48	4.7	53.7	39	0.96
49	4.8	55.3	19	0.96
50	4.9	52.2	38	0.96
51	5.0	52.2	40	0.97

Between miles 2.0 and 2.7, the battery SOC decreased by 2%. The data suggests 100% SOC ~= 0.125 gallons of gas in fuel savings or 80% ~= 0.100 gallons.

Bob Wilson

 

Re-ran the cold-soak, warm-up test tonight, 40F, and confirmed:

• 0.0-0.6 miles - car still draws down the traction battery showing good MPG. Started at 67%, rolling at 40 mph into test route.
• 0.6-2.0 miles - engine is running and sucking gas to a minimum MPG at 2.0 miles. This includes recharging the traction battery.
• 2.0-10.2 miles - there was a poorly implemented PID that allowed the SOC to vary from 63%-67%. Because this is a much flatter route.

I've got to take a nap before assembling the data including the route and altitude histogram. One late thought, I was running the car in "Normal" mode, not "ECO" or "Power." It may be if I'd used either one, the wandering SOC might have been curbed. Sad to say, it is unlikely we'll see similar, cold weather testing.

Bob Wilson

 

This is snapshot of Tire Rack specs for Ecopia replacement tires:

	Type	Ecopia	Ecopia	Nano	Ecopia	Ecopia	Ecopia	Ecopia	Ecopia
1	SIZE	195/65R15	195/65R15	195/65R15	205/50R17	215/55R16	235/45R17	205/65R15	215/50R17
2	UTQG	640 A A	640 A A	300 A B	640 A A	640 A A	640 A A	640 A A	640 A A
3	MAX.	1356 lbs.	1356 lbs.	1279 lbs.	1433 lbs.	1433 lbs.	1477 lbs.	1709 lbs.	1521 lbs.
4	PSI	44 psi	44 psi	44 psi	50 psi	44 psi	51 psi	50 psi	50 psi
5	Tread	11/32"	11/32"	9.7/32"	10/32"	10/32"	10/32"	10/32"	10/32"
6	Weight	18 lbs.	18 lbs.	17 lbs.	20 lbs.	20 lbs.	22 lbs.	21 lbs.	22 lbs.
7	Range	5.5-7"	5.5-7"	6-8"	5.5-7.5"	6-7.5"	7.5-9"	5.5-7.5"	6-7.5"
8	Rim (W)	6"	6"	6.5"	6.5"	7"	8"	6"	7"
9	Sect. (W)	8"	8"	8.1"	8"	8.9"	9.3"	8"	9"
10	Tread (W)	5.9"	5.9"	6.1"	6.4"	6.7"	7.6"	6.2"	6.8"
11	Diam.	25"	25"	25"	25.1"	25.3"	25.4"	25.5"	25.5"
12	Revs.	833	833	832	830	824	822	817	817
13	Country	US	US	JP	MX	US	US	US	MX
14	% offset	0.1%	0.1%	0.0%	-0.2%	-1.0%	-1.2%	-1.8%	-1.8%
15	% error	1.7%	1.7%	1.6%	1.4%	0.6%	0.4%	-0.2%	-0.2%

• 300 A B - OEM tire, ~30k miles, "A" grip (good), "B" temp (middle)
• 640 A A - replacements, ~64k miles, "A" grip (good), "A" temp (best)
• any of these tires should work to replace the Nano when they soon wear out
• my choice: 205/65R15 - 50 psi, corrects the GPS vs odometer/speedometer error

Bob Wilson

 

The car gave 57.6 MPG @65 mph, 75F:












Bob Wilson

 

I do change the alignment into four-wheel perfect. I did this with our 2003 Prius but also discovered the slightly over sized and heavier tires solved a straight-line, stability problem in our old, 2003 Prius.

Yes, I have driven the grooved, concrete highways around Chicago. Interesting but not a problem with our 03 Prius after the tire improvements.

The brand is not a problem with me (perhaps excepting GM.)

My requirements are:

• low-rolling resistance - tested such as the two, YouTube videos showing roll-down tests
• highest pressure - reduces the rolling resistance
• true Revs/Mile - so the instruments are as accurate as possible

Bob Wilson

 

Allergies were really bad this past week and I lost three of five work days. I made it through Friday but there was that gagging incident in the office. Still, I managed to get to the favorite drug store and a late lunch. But then the flaming eyes, especially the right eye became exceptionally painful and I was 8 miles from home.

So I chose the low traffic route home and drove back using dynamic cruise control. One of the primary optical functions is maintain a safe distance and speed monitoring. The dynamic cruise control worked perfectly. I reached home with no drama and confident I was not a traffic risk.

Without dynamic cruise control and lane departure alarm, it would have been a much riskier drive. One that I might have considered ... 'time to call a cab.'

I got home with several eye washes and took a nap. Whatever was causing the grief, some sort of allergy crusty-nasty dissolved or migrated to nirvana. I don't care as much as the right eye was no longer hurting . . . and I was home to take care of my wife.

Bob Wilson

 

"Do as I say, not as I do."​

I have always advocated 'back-in' parking at your destination. You've arrived, well rested and ready to safely back into the parking spot using all of your faculties, a well warmed car, and back-in parking is easily handled. In contrast, if you back out in a rush or distracted by your trip goal . . . bad things can happen . . . like it did last night.

I wandered to the left of the driveway and took out my own mailbox and a big part of the post. I didn't see it until later but the passenger-side, rear quarter panel is slightly disconnected, there is a gap. I don't see any other damage but there it is ... potentially a repair bill and future insurance rate hike.

Soon as I get my TIS account fixed, I'll download the body repair manual and take a look at what it takes to re-install the panel. The tail light is fine, just the panel 'popped out.'

Now my lame excuse is parking head-in made it easier to plug-in the car. But that is a lame excuse. Of course, 'why didn't you used the backup camera?' Hindsight is always 20x20 so later today, I wander down by the creek and give myself a good talkin' to. I will fix the problem but darn, am I embarrassed.

Pictures to follow.

The only good news is enough of the post remains so I won't have to put in a new one. The replacement will be white-on-white, easier to see in the dark. And of course, I'll only back-in both cars, the BMW i3-REx already, but now the Prius Prime.

Bob Wilson