Toyota Prius c: 53 MPG city / 46 MPG Hwy; Under $19,000

Nice chart for measured Volt KW/mile usage at various speeds
with 10.4 useable KW.. can compute range.



At 95-100 my volt lasted about 16min (slightly downhill).

 

Sure, people get 0.2kwh/mile in there leafs. Let's say you drive in these conditions and get 15 miles out of the 3kwh charge. At the USBMPGe of 13.3kwh/gallon that is 66.5 MPG(USBe).

We have gone 15 miles where the prius phv has gotten very good fuel economy, 25mpg seems really low. It seems like a bad assumption, but ok. If we do that every day for a year that will be 5475 miles on 219 gallons, which is pretty bad for a prius, you will have used 82 gallons(USBe) of electricity. Now that volt or leaf would likely have saved more as your routes seem to love electricity and hate gasoline, but I put it down to poor assumptions.

Ah, yes at 13.3kwh/gallon gasoline, my wind costs less than half the cost of gasoline. That maybe why most of us use higher numbers. Now why can't say the volt owners use cleaner than average electricity to substitute for gasoline? :focus:

The reason the prius c is a better choice for many than a prius phv, volt, or a leaf is that is much less expensive. That is why I think all this stuff is beside the point.

 

USBMPGe? LOL. Thanks but no thanks. The efficiency number comes from DOE so you should really give them the credit.

Since Prius can extract only 40% of energy from a gallon of gas, the usable energy is 13.4 kWh (33.6 x 0.4). For electricity, that inefficient combustion occurs further upsteam. Why do you have trouble accepting that?

Leaf doesn't have the luxury of using gasoline for high consumption driving conditions. Prius PHV does so it can cleverly pick out low power electric miles. Volt has a gas engine but it was not designed to use it (thanks to EREV marketing).

So, Leaf and Volt can't have 200-250 Wh/mile on average -- only Prius PHV can due to the ingenious blended design.

 

I suspect the numbers on that graph are based on kWhs measured from the wall plug (12.9 kWh per EPA for a full charge) rather than being relative to the usable battery capacity.

 

Using 400 Wh/mile at 75 MPH, the battery (10.4 kWh available) would run out in 21 mins covering 26 miles distance.

 

I can't do that, IIRC their number is around 82 kwh/gallon gasoline, but tries to reward substitutes for oil, as I do.

lol, if we really made 40% into motive force the prius would be much more efficient I wasn't trying to use an equivalance for efficiency ground or sun or wind to wheels. I agree with the DOE that things like nukes and wind turbines are less efficient than ICEs, but I still would rather use ineffiecient wind and sun than oil. I think your argument here is with other people.

I would rather say design constraint, but really if the prius phv can put out 5000 miles much more eff*T, er, I don't know better than the gas one, that leaf or volt should be able to too. Its not like the volt is always going 75mph in the winter and the phv is always going 30 with no stop signs. Then that other less efficient stuff, well, if you get a good number for equivalent, and this varies from person to person, you can do a comparison. My guess is using 13.3kwh/gallon gasoline that prius phv is going to save the equivalent of less than 30 gallons a year. Now it will save much more oil than that, but the electricity we are substituting has a poor equivalence.

YOu mean engineering limitations I like the phv, but its not magic. You have some really screwed up thoughts in your head, and you are not alone there, but you seem to say them quite loudly and often.

 

Nope the efficiency of 32.8 is the average for "fossil fuels", not overall.


How do you define efficiency for renewables or nuclear. I (and others) defined overall efficiency for the grid as (total power)/(fossil fuel used). I did not include the 8% transmission loss because its offset by the 8% co-generation not included in the fuel usage.

Take the EIA link I provided before and let's see your numbers to back up 32.8 overall.



The DOE GHG report you cited did not consider Volt vs Prius in the Current mix. It it is NOT based on measurements; it is a simulation study about hat might happen with 10% PHEVs on the road by 2020 and little to no changes in the charging infrastructure (requiring increasing output from coal rather than renewables, or nuclear plants). It also makes some very weak assumptions (e.g. 51% CD utilization for a PHEV40), weird charging assumptions (mostly during prime time, or a "smart charging" that is highly-demanding short-load but off peak (not very smart).

 

38% is the official measure of the current 1.8 liter engine.

42.4% and 43.7% are the concepts Toyota has been testing.

45% is the target for the next generation.
.

 

Sorry you are correct.. that is power used from the wall using a TED.
So yes 12.9Kw not 10.4.

More details in this tread
MPGe at Various Speeds

That increase the 75mph range to 32miles.

 

Or just under 26 minutes covering 32.25 miles assuming 12.9 kWh from the wall (as is likely the case). The LEAF chart gives 62 miles of range at 75 mph which would be 31 miles when roughly adjusted for the Volt.

That Volt graph looks familiar to me but I don't remember where it originates from, what it's environmental assumptions were, or whether it comes from actual measurements or is based on a computer model.

 

Those are the peak efficiencies of the engines. The 1.5L a smaller efficient range than the 1.8 peaking at 37%. The hsd does a good job using the engines in their efficient ranges. My guess is the prius phv will be able to do even a better job than the prius, since it will be able to provide more assist at the inneficient times. When its a very hot or cold day we can see by our drop in mileage that we are not using the engine only for our motive force.

 

Can you do the flipped chart, I'm more used to mpg versus speed, so miles/kwh versus speed would help me compare

 

Its measured data
see the thread at GM-volt.com (posted above as well)

MPGe at Various Speeds

 

MPGe at speeds (computation discussed at http://gm-volt.com/forum/showthread.php?8235-MPGe-at-Various-Speeds)

 

Right. These were some of my notes about the assumptions in the report from when I skimmed it last year:

* plugins will jump from 0% to 25% of all passenger vehicle sales in 10 years. So, in 2020 there will be 5,000,000 plugins sold each year in the US since the study assumes annual car sales of 20 million by that time.

* almost all new electrical generation capacity added between 2020-2030 will be coal -- essentially no new natural gas plants etc.

* implicitly, it appears to assume that plugin car sales are spread evenly across the U.S.

* all plugins are modeled as Prius-like blended mode plugins which use the gas engine up to 20% while in battery discharging mode

* the various charts and graphs are based on projected fuel mixes in 2020, not our actual current grid.

 

I got 42 mpg in "hybrid mode" (not counting grid power) averaged across a total of 16,000 miles (some 6,000 or so on gasoline) during one year of driving my Volt. Some 4,000 of the gas miles were from long road trips.

The voltstats.net numbers are derived from OnStar data but may not be fully correct. For instance, the Volt/OnStar accounting for gas miles vs. battery miles can be confused when Mountain Mode is used to generate battery power from gasoline. This is an easy optimization used to drive on battery in the city after exiting a highway while getting around 42 mpg for the generated power. The accounting gets confused and the recorded mpg comes out looking lower than it should.

Also, many of the gasoline miles represent the "last mile(s)" at the end of a trip that was mostly battery power. The mpg is poor due to a cold engine even though the total amount of gasoline used is small. This will be a common problem for the PiP as well. Often the worst gas-only mpg is from cars that have the highest utilization of grid power (fewest gas miles driven and least total gasoline consumed). For example, in colder areas during Winter months with ambient temperatues under 26F the Volt cycles the gas engine for 1-2 minutes occasionally to generate heat for the car interior as well as helping to drive the car. This also makes mpg look poor even if grid power is primarily used to drive the car.

Finally, many of the Volt statistics there are from recent owners who haven't yet learned the simple techniques for driving a dual fuel vehicle optimally.

 

uh, my 2 tonne GS350 AWD with 303hp would get 35 MPG at steady 65mph...

tough luck at getting tank mileage at those numbers... too bad cars need to slow down and accelerate again

 

:focus:
:focus:
:focus:
:focus:

 

I totally agree on both points. Part of the reason for a PHEV (like the Volt), is the ability to choose green sources of fuel.

The real advantage of the C is the price. To help with the "cost" comparison, which is where the prius C really has an advantage, I've updated

David Muse's Efficient Car Shootout Calculator from
A free calculator for Economy, Hybrid and Electric Cars

I added a column for The Prius C. Then, if cost is what matters, people can do their own 8year TCO computations. If cost, rather than reducing Oil usage, is the most important factor (its not for me), the Prius C is generally better. I assumed 19995 for the price (i.e. about 1k in options).

View attachment Fuel_Efficient_Car_Shootout-2.xls

 

you make alot of assumptions.. Cheap electricity, expensive gas: $3.95/gal, 0.11/kW, 50.8MPG in Prius.

For example our costs are $0.15/kW, $3.25/gal and the MPG was 57.9 avg for last 6K, it will go up in summer. Gas is more expensive in CA, but so is electricity, it is double of $0.11/kW

But if you wanna be impartial, the Zuma scooter wins hands down.. low cost to buy, gets 123MPG