Car & Driver Says Prime Ugly, Too Slow

Yeah, I get that, but I was thinking that Primes actually benefit from on-site L1 charging more so than Volts, and let's face it....it's greener to sit in your cube and munch on a PB&J than it is to glide over to the nearest shopping area......and by greener, I mean brown bag greener.

I'm not down with the whole ECO chic thing either, but I'm thinking that if the US gets more a little more flexible in its energy throughput, then we can be a little more flexible in geo-politics. Anything more specific would be a Fred's thing.

If MPGe really means anything real-world, then the Prime can leverage it's greater efficiency by educating companies how easy a lift L1 charging while you work can be. This will have benefits that go beyond the 22 miles or so that you get for free while you work.

It's a carrots and sticks thing.

 

I'm sitting in Denny's about 200 m from the free charger that the car reports a full charge in an hour.

All of my work is caught up but I am waiting to meet with others to coordinate before getting to go technical. So I am happy.

Really an at work charger is a management challenge.

Bob Wilson

ps. I used to complain about Denny's being slow but if your car is on a free charger.

 

I should have said oil and not fossil fuels.

 

I assume you all are using 100+ to just be 100. Otherwise it is technically impossible for you to really account for that percentage. I have taken trips that are over 500 miles in a day (it isn't pleasant but I have done it several times) and that would fit into the NHTS 100+ set. Again looking at efficiency from a single set of use cases is limiting. What would be more interesting is to equate the overall costs of operation of the two vehicles based on an average cost per kwh and gallon of gas and see where the two break even given their different numbers. The Prime is more efficient than the Volt at using what energy it stores in its batteries but stores less of it, this may favor the Prime throughout much of the usage types in the NHTS stack.

For instance those with commutes of 15 miles total round trip per day would find the Prime a more efficient vehicle given its better MPGe number are supposed to mean it goes further on the same amount of energy. The Prime is rated around 25.5 kWh per 100 while the Volt is rated near 30 kWh per 100. So for every 100 miles traveled they would save about 5kWh. Not a ton, but still an actual savings. However, as to mow past the 25 mile range, the Volt becomes more efficient but only after it has made up for its earlier extra consumption. But then as you go beyond 50 miles the Prime starts to race back to being more efficient due to its significantly higher gas mile. Where are the inflection points where one becomes better than the other but then flips back over again?

In either case, there are reasons for people to go with one versus the other, and each has its place.

 

No.

The actual data has miles driven and trip count, so you can do the actual math on either one, or you can combine them to an average for that bin (which is 215 miles, IIRC).

Here's the data:




Miles Person Trips (in millions) Person Miles (in millions) Vehicle Trips (in millions) Vehicle Miles (in millions)
Under 1 mile 31269.25 14255.16 21993.37 10116.28
1-2 miles 35846.1 37530.99 25922.51 27109.5
2-3 miles 39635.35 79652.09 28632.82 57556.35
3-4 miles 32264.09 96975.49 23084.47 69384.27
4-5 miles 22947.86 91826.2 16579.68 66344.43
5-9 miles 70510.95 455247.32 50890.79 329582.49
10-14 miles 32002.5 365108.73 23354.03 267284.25
15-19 miles 18233.33 295847.19 13556.43 220736.09
20-24 miles 11185.23 237525.76 8152.94 173544.93
25-29 miles 6671.72 174544.8 5111.29 133905.92
30-34 miles 5024.59 155816.63 3657.63 113904.41
35-39 miles 3059.21 110552.3 2251.31 81337.67
40-44 miles 2418.53 99259.86 1619.63 66446.01
45-49 miles 1676.1 77034.94 1131.23 52026.52
50-74 miles 3881.7 227027.28 2560.5 149126.22
75-99 miles 1408.7 118799.97 825.7 69339.67
100+ miles 3114.55 661163.39 1658.09 357366.43

 

There is an assumption that owning a Prime or Volt or <TDB> won't change a driver's behavior. Since getting the BMW i3-REx and now the Prime, I have changed my driving pattern to exploit free chargers. But this change in behavior is a difficult problem to model when the source data probably came from ordinary ICE drivers.

We're really back to the 30-90 mile donut/washer/ring. If you the buyer are in the center or outside, the Prime is clearly the way to go. If you are within the donut/washer/ring, then use a Volt. Projecting a population effect is nice but doesn't really address the fact that folks have different sets of requirements. To try and claim one product is superior based upon some population study may stroke an ego but does not educate a buyer.

One additional comment, using percentages is a clue that there may be a bigger truth, the absolute numbers. For example, EV cost in Huntsville runs $0.25/10 miles in our BMW i3-REx and gasoline runs $0.60/10 miles (SWAG from last summer.) So to reach the 30 mile ring, we're looking at $0.75. And in the Volt (partial fractions), $0.75 * (117/106) ~= $0.82 . . . a difference of $0.07. My recommendation is whenever showing a percentage, in "()" include the actual numbers. Otherwise, someone like good Prius Friend @john1701a might post "a big whoop" and we're headed to the briar patch again. <GRINS>

Bob Wilson

 

And that the people buying these cars won't be buying them because they are well-suited to their personal situations.

For example, nearly every in-city trip I take will fit within the Prime's Ev range. I drove 51 miles yesterday, but I had options to charge at 13 miles (L2 for 2.5 hours), 28 miles (L1 for 4 hours) and 37 miles (L1 for 2.5 hours). When I leave town, my shortest round trip is about 200 miles in the mountains (it was -4.5F when I got there last time), a typical trip is 300 miles, and a long trip is 3,000 miles.

 

I estimated those trips as all oil.

 

Exactly.

This is why I find the exercise amusing but irrelevant. If we lived in a society where only one car could be made and it had to be either a Volt or a Prime, the results would definitely mean something