calculation details of Volt's 230mpg city estimate

Just as classic as any other companies greenwashing, that has a hybrid system been out for 10 years and it has only now that it has moved to other car besides it's halo car AND the other cars with the hybrid system that gets less mpg than other non hybrid cars with a company mpg avg that is one of the lowest in the industry (minus the halo car)

 

GM may have spent more ADVERTISING the two mode then they took in from it!

 

Is that picture of an actual screen in the car? If so, it says it has 196 "range." So it can go about 184 (trip miles showing for the 4.3 gallons used) + 196 = 380 miles on a tank. 380/42.2 = 9. So it has a 9 gallon gas tank? Does that sound right?

 

November, you say?

Of which decade, I ask.

We've all been hearing about the Volt for years-n-years already. I, for one, ain't holdin' my breath for ANY rollout ... limited or otherwise.

As to the originally intended purpose of this discussion: If-or-when I purchase any EV / PHEV or any variation thereof, I rather imagine I'll calculate "fuel efficiency" over the long haul on a total cost basis; first determining the money spent on electricity for recharging plus the money spent on gasoline ... and then coming up with figures for "cpm" / cents per mile or "mdpds" / miles driven per dollar spent ....

 

That shot shows Volt being driven for 184.3 miles, battery completely drained and 4.3 gallon of gas used. If you do the math, it comes out 42.86 MPG. The computer shows 42.2 MPG so it is pretty close.

We know Volt has initial 40 miles EV range. To get MPG in CS mode, you have 184.3 - 40 = 144.3 miles and 4.3 gallon of gas was used. If you do the math, it comes out 33.56 MPG in CS mode.

We don't know the state of charge the Volt initially had. If the pack was run down and started with the CS mode, it is 42.2 MPG. If the pack was fully, CS mode gave 33.6 MPG. Without knowing SOC, we can only conclude the Volt's CS mode will give somewhere between 33.6 - 42.2 MPG. I think the pack was fully charged.

 

I don't see how you could read the screen that way. It shows the mpg and the gas used as 42.2 mpg.

The display also shows an approximated 194 miles gas range left with 4.3 gallons used, the car would have approx 4.7 gallons in the tank (9 gallon tank). This works out to 41 mpg.

I think we know what the answer is on CS mode. About 41 to 42 mpg.

 

It is going to happen. In November 2010.

There are over 80 volts running around as of today. They are building more in pre-production mode as we speak.

Ultimate Factories | Chevy Volt | National Geographic Channel

 

The screen shows Trip B. You have to take out the 40 miles on CD mode in order to get MPG for CS mode.

184.3 trip B miles - 40 CD miles = 144.3 miles on CS mode.

144.3 miles / 4.3 gallons = 33.6 MPG.

Are you assuming Trip B started with an empty battery?

 

My calculation was based on the range remaning and the gas remaining. The battery is empty now and we still have 194 miles left on gas. We have either 4.7 gallons left (9 gal tank) or 3.7 gallons (8 gal tank). Both tank sizes have been quoted by GM.

With the bigger tank its working out to 41mpg. That jives with the 42mpg listed for the gas used so far.

 

Miles left is calculated based on the average MPG. You are calculating MPG based on the range left. This is meaningless because it is a circular logic.

It is more meaningful to use miles driven (minus miles on battery) divided by gallon of gas used.

 

That makes sense, but it could be trip A (which most cars have trip a and trip b meters). Trip a could be both (which wasn't shown) and trip be could have been used for just CS mode. I am going to email autoblog and ask them.

 

How do you know they drove 40 miles in CD mode?

 

The Volt is supposed to get 40 miles in CD mode.

If we assume the battery was fully charged and they drove 40 EV miles, we get 33.6 MPG. If trip B started with battery empty then we get 42.2 MPG. That's why I said it may be somewhere in between -- see my post #205.

It is also possible that Trip B contains 80 EV miles (multiple short trips with the battery recharged and the trip was not reset).

 

That is not circular logic.

I am just reversing the process used to display the range left. It is simple math and it works out. It also jives with YOUR mpg figure assuming an empty battery.

41-42mpg. Just wait. Maybe it will be better.

 

as a matter of fact, i JUST heard that news, too ...

which is why i thanked you on the other post and replied here.

don't let the "sarcastic" tone from my previous post fool you, though ... i'm ALSO hoping it does well and WOULD consider purchasing one someday, although it seems a bit much $$$ for this particular family and I believe it's designed for only four (?) passengers ....

 

After the Nissan Just announced the price of the leaf (32k pretty much loaded with the only option being $900 for the solar panel and back up camera), GM will probably keep it under 35k (loaded). I havent seen a pre production unit that didn't have navi and leather.

 

Towards the end of this article from a few days ago they say the Volt's range and mpg targets are being met:

GM hopes to foster innovation with $8 million expansion at Warren lab | detnews.com | The Detroit News

 

There were no mention of the average speed of the test. Was it City, Highway or Combined?