What’s Better: A Fully Electric Car Or A Plug-In Hybrid EV?

I think you're a bit lost.

The "plugin version of the 2018 Toyota Prius" is the same car, with same engine and the same fuel tank as the "petrol-electric" version, just with over 10 times more battery capacity. You can drive it without every plugging it in and it'll work pretty much just like a regular Prius. Of course, if you plug it in, you can drive electric only too. So, it's all bonus from the point of view of performance.

 

So.....after 4 pages of replies......the very first one is the only RIGHT one.
(No I did not read them all.)

Really not necessary to have a second car only for occasional long trips though.
A rental works just fine in that situation.

 

Well.......when you make a post with nothing in it but a link, it is not obvious that it IS a link.
I took it for a line of plain text......as did a lot of others, apparently.

 

Except that you have to give up 1 seat and cargo space

 

I'm a perfect demographic for a well designed PHEV. I'm retired, so I go where I want when I want. I run errands a few times a week, putting 5 to 25 miles a day on my Prime. I plug in whenever I'm home and have a reduced electrical rate from the utility if I charge it off hours. Once a month I make a 1000 mile trip to Oregon to visit elderly parents. That trip takes me from seal level to 6000 feet and back. Occasionally I make a second trip in the same month to southern California.

I've found the Prius Prime to be a perfect car for my needs. During a normal month my electricity costs are lower than they were before I bought the car. When I make my monthly trips I make the round trip on two tanks of gas and fill up when it's convenient and cheap.

While there are BEVs that can make trips like this, it would have to have a good sized battery. A 75 kWh Tesla Model 3 would have a usable 250 mile range. However... a large battery like that would not work well with my daily driving. According to Battery University ** Li-Ion batteries suffer from a 5% self discharge in the first 24 hours after charging. That's almost 144 kWh a month that are wasted without moving a mile. At 20 cents a kWh that comes out to $22 a month.

If you apply that same math to the 8.8 kWh battery in the Prime you see only 13 kWh a month wasted by self discharge.

So over all, the Prius Prime is a much better match for my uses, and will be for the foreseeable future.

** Elevating Self-discharge - Battery University

 

... then don't fully charge it for the days you don't drive. Or for the Tesla, let it go multiple local short driving days without recharging at all, and then when recharging, don't fill all the way. Aim for around 80-ish %.

I thought Toyota's recharging advice was to not fill it until just before you plan to drive it. Don't leave it fully charged long enough to suffer the bulk of that 5%-in-24-hours self discharge, leave it significantly lower whenever parked. That will both save on self-discharge waste, and extend battery life expectancy. A Tesla battery could be managed the same way.

 

Perfect!

However there are some technical flaws here:

• In March 2019, my 55 kWh Tesla Model 3 Std Rng Plus came with a rated 240 mile range. I typically like to have 10 miles reserve range when approach my next SuperCharger. A year later, the improved car is rated at 250 miles and we anticipate more range in the 2021 model due to the heat pump and additional improvements.
• "a large battery like that would not work well with my daily driving" is confusing as my 55 kWh battery works just fine scooting around Huntsville, AL.
• "Battery University ** Li-Ion batteries suffer from a 5% self discharge in the first 24 hours after charging" - there are parasitic losses but self discharge does not appear to be significant in the NCA pack. Vehicle overhead appears to be a bigger drain.
• "144 kWh a month that are wasted" - it might useful to measure the parasitic loss from our 2019 Std Rng Plus Tesla Model 3:
  • 
  • ~8 kW * (2 min / 60 min/hr) ~= 0.27 kWh ... 0.27 kWh * 30 day/month ~= 8.1 kWh per month. This is much smaller than 144 kWh but mine is a Tesla. Other EVs might have worse parasitic loss. In Huntsville, we pay $0.11/kWh, ~$0.90 per month.

I'm not in the business of selling you on our Tesla EV but to bring facts and data, actual measurements. We are very happy because it runs about $0.027/mile and Autopilot has already paid for itself. We had a 2017 Prius Prime but traded it in for our 2019 Std Rng Plus Model 3 and never looked back. We found the Prime was not being driven but rather the 2014 BMW i3-REx was better in town and affordable on the road.

Bob Wilson

 

With the electricity at at least 22¢ per kWh (~ 30–35 miles per 7 kWh), it's cheaper to drive the Prius Prime in the HV mode in Southern California (~ 65–75 mpg), despite the gasoline being over $3.

 

Our testing showed driving between Huntsville AL and Nashville TN in our BMW i3-REx a couple of years ago:

• $24 - electric charged at per minute rates at EVgo and Electrify America
• $6 - premium gas to drive on the REx.
• $3.50 - Tesla Std Rng Plus, SuperCharger fee
• $2.70 - Tesla Std Rng Plus, home charging fee

Bob Wilson

 

Bob, I'm not sure how to interpret this. Are you saying that you did the same trip in two cars and only spent $6.20 for the Tesla, and $30 for the BMW?

I did the math for my Prime for the same trip (110 miles) and came up with $1.36 for initial charge and $4.87 for gas**. I find it interesting that the cost listed for Tesla SuperCharger fees was virtually the same.

Dan
** Assumptions: $0.17 kWh from grid. $3.25 for gas. 54 MPG. Both are current California prices. I see current Huntsville gas prices are only $1.69 per gallon. That would make my one way trip $3.90.

 

If I recall correctly, the charging algorithm does not bring it to 100%. It leaves a buffer in order to allow regenerative braking.

One of the things that I really like about the Prius models is that (except for the wacky gear selectors) they can be driven just like any other car. You don't have to do "just in time" charging or calculate the distance to the next fuel / charger depot. No special fuels or special infrastructure needed.

The only special thing I had to do for charging was to tell the car the time frames that I don't want it to charge due to TOD (time of day) rates. If I drive 2 miles, the car automatically adds back that fraction of a kWh. All I have to do is plug in the cable at the end of the day.

 

From other threads, we know that any such buffer is not large enough for at least some owners living on hilltops.

While that practice is available, it sacrifices some battery longevity, though I haven't seen the amount quantified. It seems that most owners, at least here in PC, are not following that practice.

As for calculating distance for next fuel, some of us have long done that for gasoline, for price arbitrage reasons. In regions with wildly different prices, there is much money to be saved by careful selection.

 

There will always be "some of us" that are not suited to some aspect of every design. I'm not that picky. I like checking all fluids at the start of a 9 hour drive and never having to be concerned about it till I'm ready to start the return trip. I stopped worrying about finding gas for 5 cents cheaper back in the early 2000s. 55 cents a tank is not worth going out of my way.

 

That is what I do when traveling in British Columbia. All prices in town are identical (except Costco just might be 5¢/liter cheaper), and adjacent towns are only a penny different.

But spreads of merely 5¢ are not at all typical of where I usually travel. In my neighborhood today (via gasbuddy), I'm seeing $2.55 at a Costco, $3.39 across the street, $3.09 and $3.59 a couple miles down the street, $2.71 at the nearest groceries. That is $1.04/gallon spread within walking distance.

Driving home last week, I skipped $2.10 and $2.04 (still unchanged, according to gasbuddy), having just been filled up by the Bank of Dad. But despite having enough fuel to get home, I did harvest $2.34 from a major chain an hour+ before home, skipping $2.25 at the ma-and-pa's. $3.49 is also available not far away, as are a very diverse spread of price points in between.

None of these lower priced places involve going more than a handful of blocks out of my way.

I do know some people who don't even look at prices, just pull in to whatever they see, leading them to pay as much as $10/tank extra on a Prius, or $15/tank extra on other vehicles similar to my Subaru. There must be plenty more people like that to keep those stations in business, without offering competitive prices.

 

Speaking of gas price spreads, here are today's prices at the most sharply spread place I have ever noticed, some years ago when fuel was slightly higher:


We took a necessary rest stop. But though being quite low on fuel, I was comfortable enough with my low fuel tank measurements (from prior tests) to not go off route to reach those cheaper stations, but rather continue on to Kingman where majors with similarly low prices were squarely on-route. And didn't get down to fumes.

In the old Subaru, that was about a $25 savings for a single tank.

 

fully electric

 

No, that spread is much wider than the normal CA vs AZ difference, which currently is only $1.00/gallon.

That is a CA tourist trap price, taking advantage of those who don't know the local differences, those who don't plan well, those who think it is only a $1 difference for the whole tank, and those who truly don't care about price.

 

All electric is great, if all you do is commute. I just purchased a Prius Prime and discovered the headache of finding an EV plug in station. Looking on line I was directed to a 110 wall outlet on the wall of a Walgreens and a Shell station with 4 Tesla only stations. Driving over 600 miles on I-5 I only encountered one with an EV station. That said, what do you do during an extended power outage?