2013 Volt: 98MPGe, 38miles EV range

Well USB, I always take in new data. I'm not going to scream "NO IT'S NOT RIGHT" And slam my head into the ground, hiding it completely.

So this is all the more reason I need to get solar installed! At least in my case, transmission losses are low as I live near the plant, but I know they are averaging it out and getting a fair number somehow. P.S. Many Volt owners like Prius owners are installing solar and doing the right things to move towards energy diversification and independence. Actually a lot of Volt owners have found that Volt ownership is what pushed them into finally going through with it!

 

You are right Brad. Since Volt's ICE operates about 39% of the miles, it's tailpipe emission would be lower than a regular no-plug Prius. Per EPA, tailpipe emissions are 87 g/mi for Volt and 178 g/mi for Prius.

However, if you include the upstream emission (fuel production), Volt end up higher (260 vs 222 g/mi) using national average grid electricity and national average gasoline production. You can lower Volt's total emission by buying green power electricity but nothing can be done with the regular Prius.

As for Prius PHV, I think it'll be lower than 222 g/mi because it has 50 MPG gas engine and it uses the electricity more efficiently, per mile.

 

Well, as I and many others have said... they need to offer in a "package" if you will with a Volt or EV purchase and allow one to get an immediate subsidy on a solar or renewable energy installation. Perhaps also included into the financing of the vehicle.

Oh and quick side note, are you then saying that a full EV like a Leaf pollutes more too?

 

It is a good and the right thing. Part of the reason is that, EPA beyond tailpipe emission information wasn't available when Volt was launched.

Now that it is out there, future buyers can include it (cost of solar panel or greener electricity) in their decision. Plus there are more plugin hybrid choices out there.

 

Leaf's emission using national average is 230 g/mi. Slightly worse than a regular Prius at 222 g/mi. However, that data was based on 2007.

2009 data shows the average grid emission is lower. Beyond Tailpipe emission calculator has yet to use the 2009 data. I would say Leaf and the regular no-plug Prius have about the same carbon footprint, now. Obviously, Leaf has an edge in lower carbon footprint in the future (assuming grid will only get cleaner).

 

That sounds about right

I'm not sure how you got those numbers.

If I take (792 g co2/kwh grid2009)*(35kw/100miles 2013 volt)*(70.7% fossil fuel/grid (209)) = 196g/mile
Now the grid has lowered carbon intensity since 2009, but this should be average for the grid. I don't include NOx or SO2 since these are regulatory emissions that would be produce with or without the car. EPA/TCEQ/CARB tightens the regulations and the polluting plants close down or add pollution controls. If you used a web app for egrid, it says that that data is from way back in 2005. Location and choice of energy is important for individuals, and the average 2013 volt on the road should do better than this.

To get the CO of the volt from this we need to know percentage electric in the volt versus using the range extender. Each person needs to do these calculations on their own.

The phv should indeed improve its CD footprint. If you use these figures it should use 162 in electric + 22 in gas = 184g/mile . This is about 6% less than the volt, but only for 30% of the distance, then it will produce more until the volt goes into charge sustain mode.

 

When you guys talk about the "upstream" emissions you mean at the power plant right?
And the emissions figures used for the individual cars is the tailpipe?
Do we have a figure to use for upstream emissions of the oil collection, transport, and refining?

 

So, you may have noticed I went quiet for a while! Let me tell you the story of a trip in the life of a Volt owner. Austin and I hopped into my car because I needed to go fetch some food. I ordered a pizza online, but made it available an hour later. I figured that way I could hypermile. We got into the car and decided that it was raining, and people weren't driving politely so I decided to just join the crowd. I accelerated up to 62mph and drove into town. It's an 11 mile trip. We arrived early, so Austin and I decided to go to the bike store. I recently got a trailer hitch, (torklift central, amazing company) for the Volt in order to pull small trailers and equip a bike rack. It's a Trek bike store, and I recently got a bike there and he doesn't have one so we checked them out. Any way, we departed and decided to go get the pizza.

I had it in sport mode, and like when I drove the Prius I don't pay attention to being efficient much. With both Prius and Volt I try to show people that these drivetrains DO NOT mean weak. Any way one notable thing is it was raining, and Austin said to slow to 15mph and then floor it. I did so, and much to my surprise it broke traction steadily until it gained traction. Really cool. Anyway, not touting performance here. He said that Prius does it at 10mph except the traction control is a bit more aggressive. Anyway did my regular zipping around in traffic.

Then I did what the PiP wouldn't be able to do for me, though I admit if I could opportunity charge and take the highway back I would be ok. I merged onto the interstate. Lately this has been a huge chore, as they are using stimuli money to extend from 2 lanes in each direction to 3. (It's technically 2 interstates in Effingham, IL Interstates 57, and 70.) So, lots of traffic, and construction. I was able to accelerate so heavily that I could have lost traction if I weren't careful. I got on the interstate because I didn't want the pizza to get cold. I got up to a cruising speed of roughly 74mph, though in the mornings there is no traffic or cops and on my way to work I used to drive 85mph. Mind you all of this with EV. It's a round trip of 22 miles, and I never drive around for more than 5 miles in town. Even in the winter when my range hits 25-30 miles I can make it without using gasoline. Now, I can blast the A/C, drive like a lunatic, and still have 40% battery left when I return home. A 2 hour charge at that point usually has me ready to hit the road again.

From my perspective I am a car enthusiast, just not the kind of car enthusiast one would find typical. I like geeky modern more efficient cars. I like things that are quiet and refined, which is why I like both Prius and Volt. Now days though, what is really amazing to me is despite the higher initial investment and all the battles and dealing with politics (yes politics in vehicles,) it is so worth it. I have been waiting for the day that I could get in a car every day, and zip to town quietly and not have an engine running, or using gasoline. I can't wait for the day to dump the ICE all together. How, and when is another story yet to be told. This is just a middle step in our evolution.

 

It is 15%-50% overhead depending on the source and location of the oil and the efficiency of the refinery, including what blend of gasoline is used. From a calculation point of view we get 8877 grams of CO2/gallon of gas. Now often in these models co2 equivalency is used. This scores lower impact for the prius since these more intense chemicals are lower.

For a prius only looking at complete combustion you get 177.5 grams of co2
Using light sweet crude coming out of the ground near by and refining it efficiently it might end up being well to wheel of 204g/mile, but use tar sands and trucks to move things around we are more like 266 g/mile. I believe USB is using a greet model that poses an average of 25% or 222g co2/mi prius. I'm sure it isn't really 25% there are weights for NOx, SO2, particulates, but in reality you can use a number to include all of that. It is not a bad approximation for average today. I don't know if they adequately evaluate the ethanol in E10, but it is not very different in ghg intensity than gasoline if land use is included. With those east coast refineries closing down that were using the more expensive less carbon intense oil, there is likely a spike up in CO2 intensity of gasoline.

 

I got Volt's national average 260 g/mi from EPA's Beyond Tailpipe Emissions calculator. Prius' 222 g/mi is from EPA as well (make sure you choose to show both tailpipe and upstream in the dropdown).

The official EPA figures are for 2012 Volt with eGRID 2010 data (which is from 2007).

Not sure how you got 792 g/kWh and 70.7% fossil fuel ratio. What's your source?

 

EVAPORATIVE emissions are very often overlooked.

This is what happens when gas sits in a tank unused for a very long time... something that becomes a big problem for a vehicle like Volt... which is likely what contributed to its delay of getting PZEV certified.

The step up in emissions rating from SULEV to PZEV involves longer overall duration of sustaining that level of clean, longer emission system component warranties, and evaporative emissions.

 

The Volt has a sealed pressurized evaporative emissions control system. I think it does really well considering that the gas does sit in there for a long time. Of course, it also protects the gasoline from the atmosphere.

 

So in looking at the graph, isn't a higher number on the vapor recovery a better thing? If so the Volt is doing really well on that front.

 

The epa grid2012 spread sheet for the 2009 grid, converting lbs/MWH to g/kwh for the fossil fuel intensity. Then used there fossil fuel generated MWH and renewable MWH to compute the ratio.

That likely uses the online version of egrid which uses 2005 data. I am not sure if my data includes distribution loss, there is no online calculator with 2009 data. Efficiency of the grid is 93.5% according to the 2009 data which would move the 2013 volts electricity to 210grams/mi. EPA site uses 64% electricity which seems fair. Say 300 grams/mile in CS mode gives 235grams/mi assuming 64% electric miles on a 2013 volt. Its probably very close to a prius today considering that gas has gotten dirtier and the grid has gotten cleaner. The only way to get much lower ghg than a prius though is to charge that phev with renewables.

If I plug in the zip, I lived in california, the calculator feeds me 190g/mi. Since I use wind now, and would likely be about 85% electric if I bought a volt, my numbers would be much lower than that. National numbers don't tell us that much.

 

This page has all the answers for you. It is very detailed and complete.

For gasoline: ​

- On average, 8,887 grams of CO2 are emitted from burning one gallon of gasoline.​

- Tailpipe CO2 emissions are multiplied by a national average factor of 1.25 to account for emissions associated with gasoline production, e.g., drilling, refining, and transportation, etc.​

For electricity:
- Powerplant emission from eGRID (2007 and 2009). This includes N2O and CH4 emissions converted to CO2 equivalent.
- Transmission and distribution loss (6.2% in 2007 and 6.5% in 2009. See p.9 in above links)
- Others (mining coal and transporting it to the power plant) which is a generic 6%.

 

Prius PHV starts in EV mode by default. High power acceleration could be considered special circumstance. For the Volt, the driver can turn on the Hold mode and start using gas as well. So, your statement doesn't make sense. Distance, power, temp and driver are criteria for successful EV operation for both Volt and Prius PHV. The thresholds for the first 3 special circumstances are different in both plugins.

Volt is not an EREV but Fisker Karma is and it is one heck of an inefficient vehicle. Now, let's move on.

 

Well, only when the 2013's hit the market will they have a hold mode. It's actually not about engaging the ICE to run off of it, but instead delaying the use of the EV mode so that congestion charges can be avoided and pollutants can be avoided when passing through city centers.

I remember also seeing something about the ICE being used to provide power to the wheels by choice. I think it's more like only if it's on, it is leaching power. Remember, the Volt cannot operate without the electric motors, even if there were a starter. It simply wouldn't function, there is no way that gear can provide enough power or ability to drive the car. However, it can operate without an engine, in the event that it was removed.

The Volt's engine doesn't come on for any reason other than being forced to come on by the hood being lifted up, a driver selected software-force of it coming online, (to float the battery at it's current level, or to build up to/maintain 40% battery for the hills because it IS primarily an EV car, and requires full EV operation to derive it's power,) or in the rare event that the engine block is below 25 degrees (which can be avoided.)

 

Yup, it is hard to beat the regular Prius with 222 g/mi without the need to plug in. The PHV version does it even better, if you can/want to plug in and enjoy the electric miles.

However, if one were to look at 98 MPGe for Volt with 38 miles EV versus 50 MPG Prius, one would think Volt is more efficient and would have lower carbon footprint. Even when compared to Prius PHV with 11 EV miles blended at 95 MPGe, one would think Volt would do better. That's not the case and there is science behind it.

Toyota did the homework and came up with the optimal balance of gas and grid electric. Prius PHV was not the first to the market but Toyota got it right the first time by collecting data with two generations of plugin prototypes.

 

Well there is a crippled EV operation. It will display a message saying "reduced propulsion" whenever the battery dips too low, such as if you don't put it in mountain mode. But that just goes to show you, it can't make up for it by utilizing mechanical energy from the engine, it can only build up a charge over time, and also leach some torque from the engine.