Toyota Mirai vs 2016 Chevy Volt

The one thing I see think I see is MPGe is apples and oranges. For the Mirai the MPGe is really MPG-H, whereas that's how many miles you get on a Kg of H2 (1 Kg H2 = 1 gal Gaso). MPGe is the EPA definition for EV's which basically assign all CO2 emissions to the power plant and none to the car. So you really have to look at CO2 per mile, which for EV you have to take average gird.

 

wow, both of them are heavy for their size.

CO2 or H2O?

 

Overall I think the article did a good job of attempting to compare these cars and their technologies. We have somewhat incomplete information about both cars but especially for the Mirai.

The overall GHG comparison should have been based on an overall ratio of at least 70% EV and 30% gasoline miles for the 2016 Volt due to its EPA Utility Factor for a 50 mile EV range. The article used 62% vs 38% which is based on older Volts with lower EV range.

The article also might have included a disclaimer that the GHG of steam reformed hydrogen is still somewhat unclear. The estimate he used appears to be on the optimistic side. On the other hand, some people expect the Mirai's mpge numbers to come out a little higher than the article estimates (quoting car & driver).

The 2016 Volt is about 300 pounds lighter than a Ford C-MAX Energi but has 2.5x the EV range (50 vs 19).

 

You absolutely don't take the average grid, as it has many old coal plants in regions with slow ev adoption, and many plug-in drivers opt for green energy. It was covered in the text. If the mirai runs on the average grid it has about the same ghg as the mirai on steam reformed hydrogen. Fuel cell advocates want credit for renewables, but if you give those to volt drivers ghg is lower for the volt than for 30% renewables for the mirai, and the gen II volt will likely be lower than calculated here. What may change over time is the fcv may get more efficient, probably by adding a bigger battery and plugging in.

Here we have one of the fuel cell lobby's points, that plug-ins are heavy compared to fcv, contradicted by their own vehicles. The reality of what happened was that going from prototype to a vehilce for sale they needed to add a lot of weight for safety that was not needed in an experimental vehicle. Mirai likely will lose weight in the next generation, but the bmw i3 shows how light a phev can be. Batteries should also drop in weight in the future.

Cost of fuel and vehicles are a big barrier to adoption in the US. In Japan its not as much of a problem as the government feels more willing to subsidize over deades. Who knows in a decade the tech may look better, but it will always be more expensive for low ghg fuel for fcvs than plug-ins. FCV are just much less efficient on renewable fuel.

 

Average coal/electric grid, is NOT that bad at all;

Fossil Fuels Are Way More Expensive Than You Think
just saying - don't believe gas/oil fuel has even got it over coal fired electric propulsion ... never mind the fact the majority of plugin's owned are running in geographic areas where more renewables are being used.
The crazy thing is - why compare them at all ?!? You can buy a Volt - not just lease. The average "You" person can afford a Volt. You can refuel both fuel sources of a Volt in most areas. But - no need to beat the dead horse any further.
.

 

I think it was a fair comparison. I'm expecting a better fuel economy out of the Mirai though.
Look, I can do magic.

It is only used with plugins now, but MPGe can be used for any fuel or mix of them. Heck, even diesel. The e is for equivalent. With 1kg of hydrogen equaling close to one gallon of gasoline, there is just no math involved in getting the mpge.
Selecting upstream GHG emissions will eventually get you to the personalize page to calculate it for a plugin. It'll give you the results for grid average and your region, and the last paragraph will state the amount of EV mix used for the model. The EPA uses 66% for a 2013 Volt.
Beyond Tailpipe Emissions: Results

 

'Unfair', I stopped reading here:

Toyota has not released an official fuel economy for the Mirai, though Car and Driver has estimated ...​

When "Car and Driver" build their fuel cell vehicle and publish the EPA stats for it, I might be interested in their analysis. Similar faux analysis were done with the Prius for as long as they've existed in North America.

Bob Wilson

 

Toyota hasn't even released official JC08 results in Japan. They did release a range, based upon JC08 results, of 300 miles, and tank size of approximate 5kgs, when they unveiled the Mirai though. CandD's estimate is on the low side, but not outrageously so. Then the numbers for the 2016 Volt used weren't official EPA, but also based upon manufacturer releases. The article used the EV:ICE ratio of current Volts, with shorter EV range, for annual GHG emissions.

For article's focus on a GHG comparison, the numbers are good enough for an initial look. The Mirai numbers will get better if the C&D estimate is low, but so will the Volt's improve with a longer EV range.

 

I think those two cars will provide an interesting comparison.
The information is incomplete though, leading to not so much a comparison as guesswork.

This is not correct. MPGe in no way assigns CO2 emissions at all. It is neutral on that topic.
MPGe is solely a measurement of energy content.

That said, drawing conclusions about CO2 emissions from MPGe would be in error for the same reason.

 

It will be interesting. I am looking forward to the fcv market to expand.

DBCassidy

 

The EPA does publish upstream GHG emissions for plugins. MPGe isn't meant to compare CO2 emissions, but the kWh used to derive those numbers can be used to assign a CO2 amount based on the grid mix.
It may take more digging, but the CO2 numbers for hydrogen production are also out there.

 

EPA displays an estimate of upstream emissions based on choice of zipcode.

Now of course this is not really for my zip code, for that you need to check my utility which is lower. Other zips in my region may be higher. They only go to 26 regional grids. Mine is ERCOT, which is where they drew the figures.

Now if I choose my old zip in california it will pull up the california grid with 200 g/mile, and my grid in palo alto was cleaner than than the california grid. YMMV The LA area grid is higher than the california average.

The Greet model for hydrogen uses california electricity, which produces lower ghg than the NREL estimates. Going back to epa, the estimate would go up.

I think the trick the fuel cell lobby tries to use is claiming hydrogen will be produced in the country with 30% renewables and electricity for the rest as clean as california. They love to over estimate how efficient the vehicles are. NREL estimates about 250 g co2/ mile for a hypothetical 68 mpge distributed hydrogen national grid.