Achieving 230mpg isn't terribly difficult. It'a not as though owners typically will be driving that far all the time anyhow. Basically, it comes from how the EPA ratings test is conducted currently and that's what GM used to come to their figure.

Think of it this way, say you have a 40mi (or less) round-trip commute to work. During the week, driving back and forth to work, you'd use no fuel. Just plug the car in at night and you're back on a full tank the next day. Then you take a longer trip over the weekend and go 200miles. Adding up all the mileage in that week, you travelled 400miles (200+(5x40)) and used approximately 4 gallons of fuel, for a total of 100mpg. That's 5 days of commuting using no fuel and then the 1st 40 miles of your weekend trip on no fuel(assuming the 200miles is one way and straight through). That leaves the last 160miles when you are using fuel and assuming 40mpg, that's 4 gallons used.

Drop that 200mi weekend trip down to 100miles and suddenly, you got 200mpg for that week of driving. 300mi total(100+(5x40)) and you only used fuel on the last 60mi of that weekend trip, again at 40mpg that's 1.5gal used over the whole 300mi for the week. 300/1.5=200mpg.

This is part of the problem with computing mileage for an EREV like the Volt, there are too many variables that will dramatically change your mileage compared to your neighbor. For instance, if you didn't take that 200mi trip, your mileage would be significantly higher. On the other hand, if you drive your car 100 miles each day, you aren't going to achieve anywhere close to triple-digit mileage.

You're on the right track with how you computed the mileage, GM just took the EPA tesat as it is and applied it to the Volt to get the 230mpg figure they touted. I don't see it as a lie, some people will achieve and even beat that. But, it should also not be assumed that every driver will achieve that because the mileage figures will vary far more than they do with our more conventional vehicles.

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Awesome, makes perfect sense. We're not looking at over, say, 80 max per distance driving but the doesn't matter because the total is so low for the week. Not that unfair it just takes training consumers who will here 230 mpg and be estatic to drive from TJ to BC on a single tank.

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The way people might see for reals 100+mpg and realize it is if they drive for a month, plugging in every night, then at the end of the month put in 5 gallons of gas, most of which was used on two 100 mile weekend trips.

That's 200 miles at 40mpg, for 5 gallons, plus the rest of the month "free".

So now you've driven your usual 1,000 miles for the month (20 weekdays at 40 miles on no gas at all plus the two 100 mile trips) on 5 gallons of gas, for 200mpg. And the customer won't have much difficulty realizing they only bought gas once this month and even at that only 5 gallons of gas.

Is that a stretch? I dunno, maybe it is. But that's when you're talking 200mpg.

Reaching 100mpg (only using 10 gallons in a month) is easy as pie. Say you drive 50 miles on a weekday, 40 of them free, plus 10 each day on gas (1/4 gallon used each day). You'll use 1 and 1/4 gallons of gas each week, for a total of 5 gallons there, plus 5 gallons on the two 100 mile trips. Now you've gone 1200 miles in the month (okay, 4 weeks), on 10 gallons of gas, you're still making 120 mpg, but filling your tank a bit more than once a month.

Of course, all these calculations are ignoring the price of the electricity you draw each night, and I don't mean to write that off. But anyone who drives the car in these usage patterns will quickly reach the conclusion (accurately!) that they are getting 100-200 miles for every gallon of gas they buy.

If your criteria isn't so much the actual cost of driving, but how much gas you use (your carbon footprint, your use of foreign oil/fueling terrorists, or maybe you just don't like gasoline because a tanker truck ran over your dog once) and you have an anything like normal car usage pattern, this vehicle is going to seem like heaven to you.

The only real question is how many people are willing to pay that much money to reduce their dependence on gas/oil?

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Does anyone here notice that this is just a different take on a system that has been proven to be very efficient in diesel-electric trains? This system is a proven success, domesticating it for everyday use is GM's biggest challenge. In other words, making it so that you don't need to be a trained engineer to run the damn thing.

Back to the MPG issue. The MPG possibilities with this type of system is almost infinite. Bases on the application, be it an economy car, luxo-barge or super car is what will determine the mpg rating of these cars. Application will determine type/power of motors used, which will in turn its power requirement. Power requirement will determine the size of generator needed, which will in turn decide the size of the internal combustion engine.

On the Volt, being the first of its kind out of the gate, and the fact that the bulk of R&D dollars went to the battery and software development, they grabbed the 1.4L engine because it is the most efficient one that they have in hand. For a car this size, maybe that 3 cylinder thing that Lotus is working on is all that is required. For a luxury application, maybe a de-stroked V6 could work for Cadillac. A torque optimized 2.0 liter V6 running @ 2500 rpm, powering 4 hub motors would be ideal for a Caddy that rivals the Lexus barge.

Remember this is only the first of a new breed of cars, the next generation will be much improved.

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Please, are you seriously comparing this to diesel-electric trains which have no battery at all and burn a metric ton of fuel (literally)?

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While it's a highly optimistic claim requiring some specific assumptions, it's not completely baseless. They're looking at the overall "mileage" for that 80% group who drive 40 miles or less a day most days. In fact I think that if they were allowed to start with a charged battery, they'd run any of the current EPA tests on battery power alone. Clearly that won't be a valid test, so either there will have to be new EPA tests for this sort of car or they'll have to run the test once in fully-charged mode and once in charge-sustaining mode and take an average or something.

And as to whether or not they'd like a "do-over"... I think they're close to the position where almost any news about the Volt short of a cancellation of the program is good news because it keeps the car in Americans' very short memories.

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I love this car.

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Why?

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Pathetic. Someone from a news network you don't watch interviews someone about a car and you have to show everyone here how much of an idiot you are.

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Right. All the liberal news outlets (every one else) are completely devoid of opinion.

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I think you are confused. They never once said that the gas engine would achive 50-150mpg, I've always heard that it would be about 40-50mpg. The higher mileage comes from combining the mileage driven on battery power alone and figuring in when the range-extender would be used. I think that's the figure you are latched onto and assumed is from the range-extender alone, which was never claimed.

I think you need to read up more about how the Volt works.

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I deleted the part why i thought so :

Prius engine efficiency : 37%

And ICE engine max efficiency on const load const rpm : 63%

If an alternative engine with co-generation system efficiency : 82%

Let say generator is 90 % efficient and motor is again 90% efficient : so 63% translates to around 50% efficiency : which is again higher that prius engine efficiency.

Now the beauty is they can use a very high efficiency,constant load ,const rpm engine and pump the efficiency numbers up and as its software controlled, the load also can be factored ( saw you don't need same power when one person is traveling and 4 people traveling ). So by making output as a function of these factors you will be able to derive a better number than prius and get 70 mpg for sure.

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Unni,

you are crazy to think any conventional ICE can get 63% THERMAL efficiency. It's just not possible without some expensive cogeneration or something along those lines. You throw out 30% alone just from exhausting the hot CO2.

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If you think a 100hp motor in a 4000 lb. car is going to get 50mpg you probably would fit right in at GMs PR department.

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