科技前沿:雪佛蘭Volt:仍面臨許多未解難題

【英文原文】

Chevy Volt: A lot of unanswered questions
While General Motors continues to define itself post-bankruptcy, it is pushing ahead with one of its key pre-bankruptcy projects: developing the Chevy Volt.

This week, a team of GM vehicle engineers is testing eight battery-powered Volts on a three-day, 1,200-mile drive from southeast Michigan to Pittsburgh.

The engineers will evaluate everything from the sound system to the seats, but most of their attention will be focused on how the Volt performs under electric and gasoline power.

Lots of questions remain, as I discovered when few a words about the Volt at the end of my last column drew a number of heated responses.

My comments focused on speculation about the performance of the Volt after the batteries discharge and the range-extending gasoline engine kicks in.

Sine the Volt weighs close to 4,000 pounds, according to a knowledgeable source, and the engine only displaces 1.4 liters, some have guessed the Volt would be a slacker under gasoline power.

"Absolutely incorrect," says a GM spokesperson. "There is no degradation in the Volt's performance after the battery has reached its lower state of charge. The engine-generator provides sufficient power to propel the vehicle."

GM says that the Volt will be able to accelerate from zero to 60 miles per hour in 8.5 to 9 seconds, whether it is running on battery or engine-generator power

【中文翻譯】

儘管通用汽車（General Motors）仍將自己定義爲後破產時代，但其還是在推進破產前就已經進行的一個重要項目：開發雪佛蘭Volt（Chevy Volt）電動汽車。

上週，一組通用汽車的工程師們對8輛電池驅動的Volt汽車進行了測試，從密歇根東南部開到匹茲堡，爲期3天，共1200英里。

工程師將評估新車的所有部件，從音響設備到座椅，但是他們主要關注的將是Volt在電力和汽油驅動下的性能如何。

在上一篇專欄的末尾，我就對Volt做出了簡短的評論，談到Volt還面臨着許多尚未解決的問題，引起了熱烈的反響。

因爲Volt在電池用完後，由內燃機對電池進行充電以延長行程，我的評價主要關注的是推斷使用內燃機充電時Volt的性能。

據可靠消息稱，Volt重量將近4千磅，其發動機僅爲1.4升，於是一些人猜測Volt在汽油驅動下將會變得出奇的慢。

通用一位發言人稱：“這種觀點完全不正確。在汽車電池達到低電能的時候，Volt的性能並沒有任何下降。內燃機發電機能提供足夠的能量驅動汽車。”

【英文原文】

That's not all. Also under scrutiny is GM's oft-repeated assertion that the Volt will have an all-electric range of 40 miles. Critics point out that the car needs ideal conditions to do that.

For one thing, the 40-mile range depends on ambient temperatures of 60 degrees to 65 degrees. When the temperature drops below 60, the batteries become less efficient. And if it gets hotter than 65, the air conditioner can impose an additional load on the Volt's batteries. Either way, the range diminishes.

Nor does the 40-mile range accommodate aggressive driving or sustained uphill climbs -- you don't have to be a budding drag racer or hill-climb contestant to get less than the full range on electricity.

Other questions about the Volt are almost philosophical: Just what is GM is trying to achieve with the Volt, and how much value does it provide the customer?

For instance, compare the Volt to the best selling gasoline-electric hybrid, the Toyota Prius. The goal of the Prius is to use less gasoline. Therefore, it carries 230 lbs of batteries that give an assist to the 1.8 liter gasoline engine to improve the car's fuel economy. The Prius has an all-electric range of only about a mile, but it gets 50 miles per gallon of gasoline.

And oh yes, the Prius starting price is $23,750.

The Volt, in contrast, wants to almost entirely do away with gasoline. Therefore, it carries a hefty 400 pounds of batteries that can propel the car up to 40 miles under ideal conditions. But once the batteries have been depleted, the Volt is powered by a conventional 1.4-liter gasoline engine that gets conventional fuel economy.

And the price for the Volt hasn't been set yet, but it will likely be a tad under $40,000, minus a $7,500 government rebate -- a good bit higher than the Prius.

So here's one way to look at: The Volt will be easier on the environment, but only if you don't mind paying a premium and drive fewer than 40 miles per day.

The Prius weighs more heavily on the environment but performs consistently under nearly all conditions and cost less.

Choosing between the two will be up to customers, beginning at the end of 2010 when Volt is scheduled to go on sale.

【中文翻譯】

通用稱Volt將能夠在8.5到9秒之間將車速從0加到每小時60英里，不管是用電池還是用發電機電能。

這並不是所有問題。同時受到人們懷疑的還有通用不斷重申的一點，也就是通用稱Volt的電池能夠行駛40英里。而批評者指出要達到這個標準，汽車需要處於最理想狀態下。

首先，要達到最大行駛距離40英里取決於電池周圍溫度，要求爲60 °F到65 °F（16--18°C）。當溫度低於60 °F，電池能效就下降。如果溫度高於65 °F，那麼車內空調可能會給Volt電池帶來額外負擔。不管是哪一種情況，行駛距離都將減少。

而且40英里的最大行駛距離也沒法適應高強度的駕駛和持續的爬坡——你並不非得是個嶄露頭角的汽車拉力賽選手或者爬坡賽選手，才能夠減少電池所支撐的最大行駛距離。

關於Volt的其他問題則更加理論化：通過Volt，通用想達到什麼目的？通用能夠爲消費者提供多少價值？

比如，將Volt同最熱賣的油電混合動力車豐田普銳斯（Toyota Prius）進行一下比較，就可見一斑。普銳斯的目的是要減少汽油使用量。因此，普銳斯裝有230磅的電池以輔助1.8升的內燃機，提高汽車的能效。普銳斯電池的最大行駛距離只有大約1英里，但是每加侖汽油的行駛距離則爲50英里。

啊，還有，普銳斯的定價爲23750美元。

相反，Volt則希望完全擺脫汽油。因此，車上裝了400磅笨重的電池，能夠在理想狀態下驅動汽車行駛40英里。但是一旦電池用完，Volt則由傳統的1.4升內燃機以最普通的能效驅動。

Volt的價格還未確定，但很可能會稍低於4萬美元，再減去政府7500美元的退稅，還是高出了普銳斯許多。

因此總結一下，可以這樣看：Volt會減少環境的污染，但是前提是你不介意其較高的價格，並且每天開車少於40英里。

普銳斯給環境帶來更大的負擔，但是性能在幾乎所有情況下都較爲穩定，並且價格較低。

要在這兩款車之間做出選擇完全取決於消費者，也就是在2010年底Volt計劃的上市銷售時間，我們將拭目以待。