Prius Plug-in and Volt Pros and Cons

Nonsense. That is the practical range of EV designs that cost less than $40,000 with 2006-era battery technology which is why almost every EV that is available now in that price range has that range capability.

Nissan was quietly but actively exploring the EV market back then which resulted in the LEAF which came off the assembly line at essentially the same time as the Volt and was delivered to customers a few days earlier in late 2010.

Not to mention that 70-100 miles was also the EV range of the earlier generation of cars like the first EV-1 models as well as the original RAV4 EV, and the Honda EV Plus that were available from 1997-2003 (just 3-4 years before the Volt concept) but at impractically high cost using NiMH cells.

 

GM had talked up the serial PHEV design for so long, that when the car finally came out the fans were dumbfounded to find out they had a Prius copy with a bigg(er) battery.

 

Then why do you keep distorting the Volt's design? Shouldn't you be celebrating its market diversity and then separately urge GM to build addition models with other design tradeoffs?

Toyota's Prius Plugin seems like an analogous "one-size-fits all" situation but I can't recall seeing you promoting the idea that they should additionally build a PHEV with more of an EV focus and a larger battery range. Have you?

 

It was an EREV hybrid when it came out just like the original concept car except with an additional power-split path for added efficiency. Boo-hoo. People were initially surprised and some are still confused.

 

Incidentally, SageBrush, isn't that the kanji for gold?

 

"You keep using that word. I do not think it means what you think it means."

IMHO a "next generation" transaxle for use in a vehicle who's primary purpose is to reduce energy consumption would be presumed to be more efficient than its predecessors. The Volt is less efficient than the PiP when driving under gasoline power, and less efficient when driving under electric power. So in what sense is the transaxle "next generation?

Yes the Volt has a considerably bigger electric motor, so it can accelerate harder and drive faster under electric power. Yes the Volt has a considerably larger battery, so it can drive further on electric power. Neither of these would seem to have much to do with the differences between the GM and Toyota transaxle that I can see.

Given these basic design choice difference between the PiP and Volt, the Volt is a decent choice for some drivers. Particularly those who regularly fall into its sweet spot of 18-70 or so miles between charges where the Volt's overall efficiency exceeds that of the PiP by virtue of its larger battery. That's great.

Rob

 

Excellent. When you don't like what the data has to say, attack the formatting, act confused, and obfuscate.

Yes, its wall/AC. As it says in the text before and after the graph. So just how much power does the Volt's battery cooling system waste, and under what range of temperatures?

Yes the source is the Argonne (ANL) data as mentioned.

Incidentally, here is the same calculation made from the DC data.



MPGe is the total amount of energy consumed from any source, expressed in terms of its gasoline equivalent. Hence the e. X axis is distance in miles. Before the "knee" both vehicles are running all electric, after that the gasoline consumption starts pulling down the average MPGe. The knee for the PiP+ comes considerably later, as its able to get more miles per kWh of electricity. The PiP+ also gets pulled down slower after it starts burning gas, as it gets more miles per gallon.

800 lbs may be the difference in vehicle weight, but iplug clearly stated he was talking about the difference in battery weight. I would say his assumption is correct, as to the best of my recollection most Gen II Prii with a 10kW plugin conversion saw little to no impact on mileage from the extra weight, and often get slightly better mileage just as the PiP does.

Rob

 

I'm not as sure. The Volt battery weight of 435 pounds is probably the 16 kWh pack from 2011-2012. I'm not sure what the weight of the 16.5 kWh pack from model year 2013 and 2014 is.

In any case, the 16 kWh pack at 435 pounds is 3.64 times the capacity of the PiP's 4.4 kWh pack that weighs 176 pounds.

I'm just starting to parse the scenario put forward by miscrms which seems to posit around 13 kWh from the wall socket. This would seem to imply a Volt-sized 16-17 kWh pack. If you simplistically scaled the PiPs battery pack weight by 3.64 you get about 640 pounds. If you then add that to the PiP's weight (adjusting for the existing 4.4 kWh pack) you get 3629 pounds. Maybe a larger PiP pack would scale better since the full Volt pack is 205 pounds less than 640 but on the other hand more pack weight means more structural support, more suspension, and larger diameter wheels and tires. I suspect a PiP with a 16 kWh or so pack would end up weighing within 150 pounds or so of the Volt and CMAX Energi which weight around 3750.

The added weight and tire diameter (aerodynamics and LRR tire patch) will almost certainly have a noticeable effect on efficiency.

It wouldn't surprise me if the PiP were still more efficient than the Volt and Energi after making that adjustment. It's worth noting that the Energi and Volt weigh about the same, have about the same EV efficiency, and have almost identical highway hybrid efficiency even though the Energi is using an HSD-style transaxle.

I don't have detailed calculated numbers to back it up, but I'm guessing the Prius gains some efficiency by using 600v motors and a more efficient inverter.

 

Remember that a compact car should be more efficient than a midsize. We have a complete opposite here.

It is clear that efficiency is reduced in attempt to use more electricity. Where is the line before both the gas and electric efficiency begin to take hit? The answer is PiP configuration with 4.4 kWh battery.

This most efficient "next gen transaxle" came out in 2009 with Gen3 Prius. It was designed with PiP in mind. Where is the proof? See the PiP prototype with a different battery pack. It had 5.2 kWh pack but did not fit flat in the cargo floor.

Volt transaxle is a step backward. It reduces both gas and electricity efficiency in attempt to increase EV ratio. The big non-sense MPG displayed in-car got people greenwashed, creating an illusion that it is more efficient due to higher MPG and using less gas.

I have seen Leaf owners getting ~130 MPGe. That's about what my PiP got on electric miles. Volt's 98 MPGe is low, especially for a 4 seated compact. Even the bigger C-Max Energi is rated better. For gas efficiency, nothing can top PiP, made possible only by the "next gen transaxle".

In summary, PiP got the electricity efficiency of Leaf and gas efficiency of Prius. The best of both worlds.

 

The selling points for Volt have been "EV at all speeds" and MPG that's "vastly superior".

So, it's rather ironic that those are actually both gas & electric efficiency sacrifices.

The mindset of faster & higher being better is a marketing problem we'll likely have to deal with for many years to come. People don't recognize the benefits of blending. They see MPGe values and simply dismiss them due to lack of understanding what they actually represent.

Greenwashing has been a very effective tool in the past. People pass along and contribute to the misleading without even realizing what they took part in. The effort feeds upon itself, leading us down a path we assume is better without taking the time to verify whether it actually is.

That step backward will eventually reveal itself as a shortcoming. The cost aspect of it is already starting to become apparent. In the meantime, we have to find a way of dealing with the illusion.

 

Bill, why can't you see that the Volt is better for some drivers/commutes and the PiP is better for some drivers/commutes? Even though I don't think you intend to, you are coming off like the Volt is better in every possible way and better for every driver.

I think the Volt is a great car, but it would not work for me. I routinely need a lot of space to haul stuff and routinely haul 5 passengers (including me). I also take a lot of very long road trips.

So please don't assume the Volt is best for everyone. And quit saying that the PiP is best for people that like pumping gas. That just makes you sound stupid.

 

Total combined MPG is a completely valid metric, especially for people who primarily care about the economic and national security aspects of reducing imported oil.

I wish the Volt displayed other summary results as well like Wh per mile, combined MPGe, etc. I also wish the PiP displayed its data better since some of the important numbers get absurdly truncated due to lack of display area.

Of course, you are conflating EPA estimates and anecdotal experiences. The CMAX EPA EV efficiency and HV highway efficiency (100 vs 98 EV MPGe, 41 vs 40 HV mpg) is only very slightly better than the Volt.

You've seen Volt owners getting 130 MPGe also. This was my summary result for my Volt top ten MPGe list entry:

Details at:

Jeff N - Volt - Top 10 MPGe | PriusChat

You're making possibly unwarranted assumptions about the efficiency of the Volt transaxle and the various component efficiencies and energy paths in the Volt. There is clearly room for improvement but I haven't seen much detailed evidence for where those improvements are best obtained.

PiP gets excellent efficiency in both EV and HV. The Volt gets great efficiency on EV and lets you do it 3.5x farther before the gas engine has to kick on.

 

There is a big difference between the two cars. PiP tracks the portion of the miles driven in EV and the kWh it consumes. Volt doesn't track or display the kWh usage but religiously display the gas consumption. Pretty dumbfounded attempt at greenwashing, considering majority of Volt's miles would be using electricity.

PiP isn't perfect but the best balanced plugin on the market. It is not for everybody but a darn good solution for many. PiP is very efficient on either fuel. Depending on one's commute pattern (range, speed, charging pattern, etc), fuel ratio will be different but you can bet PiP will get the most out of both fuels.

The battery will improve and more range can be fit in the new dedicated plugin model (read NS4). SiC transistors would further boost it.

Even Jeff's best 1,000 mile tank is 130 MPGe (corrected). Per Voltstats.net, half of the owners don't break 70 MPGe and that's with 80-90% EV ratio!

That's the same mentality as the SUV drivers when a gallon of gas was 99 cents. It doesn't justify wasting it. There are emissions associated with generating electricity. Electrons coming from Coal is cheaper than those coming from solar panels.

 

This has been discussed and was suggested to use different acronym for that purpose.

Traditionally, MPG was used for Fuel Economy. It was used for single fuel cars like gas/diesel powered and hybrids.

When another source of fuel was introduced in plugin hybrids, MPG is simply gas consumption. It is NOT fuel economy. Fuel economy for plugin hybrids use MPGe with electricity counted as fuel.

I was using the year round average for both Leaf and my PiP.

Your one year average MPGe is what we need to use.

 

That wasteful smug reminded me of the SUV craze too.

We were encouraged to waste because it was "good for the economy".

 

Yea, big, heavy and feeling powerful. What a repeat! This time, in electric version.

 

False. Starting in model year 2012 the Volt displays kWh used just like the PiP.

The Volt has always displayed the number of miles driven in EV vs. HV modes along with accurate and fine-grained gasoline consumption.

Ahem... My top ten entry was 115.7 MPGe.

As you should already know by now, the VoltStats.net combined MPGe number is useless because the site cannot get the actual EV efficiency data from OnStar.

A car with 80-90% EV ratio might easily be getting 130 MPGe EV-only efficiency but VoltStats just assumes the 95 or 98 MPGe estimate from EPA when they calculate the combined MPGe number.