Prius Plug-in and Volt Pros and Cons

It pops up and disappear after you turn off the car right?

My understanding is that it doesn't track it so owner can go to a screen and see the "trip A" or lifetime average. The only way you can find the lifetime kWh is from a report from a website and that also has the field as blank. Fishy.

 

Bill, I have driven 2011 Volt and 2011 Leaf. I have not driven any of Ford Energis.

 

Yes, but you can bring it up at any time by hitting the dedicated physical efficiency display button on the center console.

The website has been broken/flaky for a few months but was generally reliable before then.

The kWh used and the EV vs HV miles display screen in the car gets reset every time you do a full battery charge.

 

That's the point. An owner would have to do that.

That's like having to collect all gas receipts and do the math to get MPG.

Modern cars display instant MPG and tracks the overall number. Volt does it for gasoline but not for electricity. Go figure. If you ask me, it is intentional greenwash effort or a white lie, whatever you want to call it.

 

Go tell Toyota... The PiP display also displays total combined mpg. It says "Cons XXX MPG". The Volt display just says "XXX MPG". Neither car display says "fuel economy".

 

Okay. Before the efficiency displays at MyVolt.com went haywire on me late last year, I took a snapshot of my annual efficiency between June 2012 and June 2013.

This particular page has a pull down menu that would display either 30 day or 12 month averaged data. It always consistently showed an electric consumption number around about 15% or so more optimistic than a different 30 day display page which was consistent with my own daily records. My assumption is that the more optimistic page did not account for charging overhead. So, my numbers below are adjusted to account for additional charging overhead:

Adjusted 132 MPGe EV
Adjusted 84.5 MPGe combined
46 MPG HV
70% EV, 30% HV

These annual averages are completely consistent and believable because I was closely tracking my monthly efficiency during that period and I was consistently getting 250-260 Wh per mile every month.

Here is the raw data summary:

 

"Cons" stands for consumption. PiP tells you that it is not fuel economy MPG.

Volt does not differentiate but instead it misleads.

 

If it was done the same way in a BEV like Leaf, it would drive owners nut.

The difference with Volt owners though, they don't seem care about electricity efficiency. They just love to look at how little gas they use, dazzled by the big misrepresented MPG. I gotta wonder if it is due to what Volt readily display and what not.

 

All plugin cars that I'm aware of do not include charging overhead in their "kWh used" displays inside the car.

The main initial efficiency display page on MyVolt.com (when it used to work) seemed to include charging overhead (it was within 3% of the number reported by ChargePoint) but another efficiency page whose image snapshot I just used in an earlier post seemed to display the battery-level kWhs used (as in the display inside the car).

Obviously, the pages should have been made consistent or the differences more clearly documented but the more frequently seen page included the charging overhead. Nissan's CarWings website had its own issues. This is all 1st gen stuff done on limited marketing budgets. I'm hoping GM will upgrade and fix the site for the Volt 2.0 rollout. Perhaps Toyota will create such a site for the next gen Prius Plugin.

As far as gas consumption and odometer readings, the Volt gas consumption display is almost always within 1% of the gas pump on the several times that I have checked it carefully. Sometimes it shows slightly more gas consumption than the pump and sometimes slightly less. The Prius (including PiP) is well-known here for being 2-4% optimistic on gas consumption.

I noticed while driving a PiP for a few days that it also showed more miles traveled over the same route as my Volt. I recall it was around 2% different. I'm not sure which car was more accurate but the PiP odometer reading would have led to a more optimistic mpg calculation.

 

Nonsense. Many Volt owners care a lot about EV range and that's ultimately the same thing as EV efficiency. Quite a few Volt owners report regularly getting 45-50 miles or more of EV range on a single charge which implies around 130 MPGe EV.

 

USB, you said on a post to the Top 20 MPGe thread in February that your one year EV efficiency was 132 MPGe and your HV efficiency was 56 mpg. What was your EV/HV split and overall combined MPGe?

As I just noted, my annual Volt averages after driving 24,000 miles were:

Adjusted 132 MPGe EV
Adjusted 84.5 MPGe combined
46 MPG HV
70% EV, 30% HV

 

44% EV, 66% HV
132 MPGe EV
56 MPG HV
75 MPGe combined

My PiP - After One Year (Stats) | PriusChat

That's with 15% (general) charging loss added. Note that last year's NY winter was worse and longer than usual. I am sure you'll do better with PiP in California.

 

We have owners like Bill that likes to brag how high speed EV, fast EV acceleration and cheap electrons.

I wonder how he is doing with his fuel economy.

 

However, it's not a linear phenomenon, so the assumption still should work.

For example, the non-PiP Prius battery weighs 90 lb but gets only about 1 mile of EV range. If you use the same math as you compared the PiP to the Volt, scaling the non-PiP Prius battery pack weight by ~11 and comparing to the PiP, you also get some numbers that don't add up.

The theoretical upscaling of the PiP battery proposed has been tried, as miscrms mentioned. All this could and has been done without any significant added weight in the form of suspension or other supporting structures.

 

Agree. If any vehicle manufacturer had the technical capability to match the Prius ICE, it would be foolish not to use it.

As for the market today, the Volt would have no significant niche except for going with the larger battery with suboptimal ICE. Who would buy the other theoretical option? A Volt with Prius ICE technology would be a game changer.

Just like the PiP, the Volt is a great car. If we are mostly concerned about MPGe and gallons of gas avoided, each vehicle appeals to its own large share of commuters, depending on commuting habits.

For me, considering MPGe and gallons of gas avoided, the PiP is a much better choice. For those the numbers pencils out better for the Volt, that's awesome and that's probably the better vehicle for them.