This is what happens when you hit the gas - Shannon Odell

譯者: Lilian Chiu 審譯者: 穎君 紀

In 2015, two men drove a Volkswagen across the continental United States

2015 年，

兩名男子駕駛一輛 福斯汽車穿越美國大陸，

on just over 100 gallons of fuel.

只用了一百加侖多的燃料。

Their 81-mile-per-gallon performance doubled the car’s estimated fuel rating,

他們每加侖能跑八十一英里的表現

是這輛車的估計油耗效能的兩倍，

and set the record for the lowest fuel consumption ride of a diesel car.

也創下柴油車最低燃油消耗記錄。

The duo call themselves hypermilers

這兩人稱自己為超節能車手，

and are experts in techniques that maximize a car’s fuel efficiency,

他們是專家，精通將汽車 燃油效率最大化的技巧，

such as the pulse-and-glide.

比如加速滑行技術。

In the pulse, drivers accelerate slowly

在加速階段，駕駛會緩慢加速，

until they’re traveling slightly above their intended speed.

直到他們的行駛速度 稍微超過欲達到的速度。

They then slowly release the throttle and glide,

接著他們慢慢放掉油門，進行滑行，

until they’re slightly below, and repeat.

直到略低於那個速度，接著再重複。

To understand why this strategy saves fuel,

若要了解為什麼 這項策略可以節省燃料，

we first need to unpack what exactly is going on beneath a car's hood.

我們首先需要探討 引擎蓋下發生了什麼事。

Non-electric cars run on internal combustion engines,

非電動汽車

要靠內燃引擎（ICE）來運行。

or ICEs.

Cars are often advertised as sporting a 4-, 6-, or 8-cylinder engine,

汽車的宣傳通常會提到它裝載的 是四、六，或八氣缸的引擎，

which refers to this device's main components.

指的就是這個裝置的主要部件。

Within each of these cylinders is a piston,

每個氣缸中有一個活塞，

which moves up and down,

它可以上下運動，

spinning a bar known as a crankshaft,

驅動一個叫做「曲軸」的橫桿轉動，

effectively converting linear motion into a rotary motion

有效地將直線運動

轉換為能驅動車輪的旋轉運動。

that can drive the wheels.

What powers these pistons’ movements

這類引擎的名稱由來，就是 這些活塞運動的動力來源：

is what gives these engines their namesake: combustion.

燃燒。

As the piston lowers, air and fuel are sprayed into the cylinder’s chamber.

活塞下降時，空氣和燃料 會被噴入汽缸腔內。

Then as the piston rises, this air and fuel mixture is compressed.

接著，活塞上升時，

空氣和燃料的混合物會被壓縮。

In gasoline engines, a spark is introduced,

汽油引擎則是利用火花

igniting the gas.

點燃氣體。

In diesel engines, the compression alone creates a mini explosion.

在柴油引擎中，壓縮這動作本身

就會造成迷你的爆炸。

This combustion causes an immediate increase in temperature and pressure,

這種燃燒會讓溫度和壓力立即上升，

propelling the piston down, as it starts the cycle again.

把活塞推下來，開始下一次循環。

The gas pedal controls the amount of air and subsequent fuel

油門踏板能控制有多少空氣

和隨後加入的燃料會被釋放到汽缸內。

released into the chamber.

The more fuel in the chamber, the more powerful the combustion,

汽缸中的燃料越多，燃燒就越強大，

making the crankshaft rotate faster.

曲軸的轉動速度就會更快。

Driving down the highway, ICE cars spark thousands of blasts per minute.

行駛高速公路時，

內燃引擎汽車每分鐘 會產生數千次爆燃。

But explosion-power driving is pretty inefficient,

但，靠爆炸的動力來驅動 是相當沒有效率的，

as much of the energy generated is lost to heat.

因為產生的能量大部分 都會轉為熱能流失。

In fact, only 16 to 25% goes towards moving the wheels.

實際上，只有 16~25％ 的能量

被用來轉動車輪。

These explosions also create CO2,

這些爆炸還會產生二氧化碳，

and ICE engines produce 15% of the total global carbon emissions.

內燃引擎

產生的碳量佔全球 碳排放總量的 15％。

The pulse-and-glide can increase efficiency for two reasons.

加速滑行法之所以 能提高效率，理由有二。

First, when accelerating to higher speeds during the pulse,

首先，在加快到更高速的加速期間，

the engine works at a higher efficiency

相對於以較低的速度等速行進，

compared to traveling at a constant lower speed.

加速時引擎的效率會更高。

And second, modern car engines shut off fuel injection or idle,

第二，現代汽車引擎

在減速時會停止 注入燃油或進入空轉。

when decelerating.

Meaning that as the car glides,

意思就是，當汽車滑行時，

the wheels are driven by inertial energy, rather than combustion,

車輪是由慣性能量驅動，

而不是燃燒，

ultimately saving fuel.

最終，就能節省燃料。

But even at their peak performance,

但是，即使在表現最好的時候， 內燃引擎超節能車手

ICE hypermilers can’t compete with the true champion of fuel efficiency rides:

也打不贏高能源效率行駛的真正王者：

the electric vehicle.

電動車。

Many EVs run on induction motors, which have two main parts:

許多電動車的運作是靠感應馬達，

這種馬達有兩個主要部分： 一個定子和一個轉子。

a stator and a rotor.

The stator is a series of rings, with copper wires wrapped around it.

定子由一連串的環 組成，上面纏著銅線。

By conducting electricity at variable rates,

透過不同速度的導電，

these wires create a rotating magnetic field.

這些銅線會創造出一個旋轉的磁場。

This field induces the rotor with electrical current,

這個磁場會感應轉子，產生電流，

causing it to spin, and driving the motion of the wheels.

讓轉子旋轉，

驅動車輪的轉動。

For EVs, pressing on the accelerator changes the frequency of current

就電動車來說，踩下油門

會改變將電池注入定子銅線的頻率，

driven into the wires of the stator,

in turn increasing the rate at which the rotor spins.

接著便會增加轉子旋轉的速率。

By utilizing battery power rather than gasoline,

因為使用的是電池而非汽油，

65 to 69% of the energy consumed by EVs

電動汽車消耗的能量中，有 65~69%

goes directly to moving the wheels.

是直接用於轉動車輪。

And since EVs don't create explosions, fewer parts are needed below the hood.

且因為電動車不會產生爆炸，

引擎蓋下方需要的零件就更少了。

While a typical ICE vehicle has over 2,000 moving parts

典型的內燃引擎車有 超過兩千個運動零件，

to help contain, cool, and maintain combustion,

用來協助遏止、冷卻，和維持燃燒，

a typical EV has about 20.

典型的電動車只有約二十個零件。

EVs are completely changing the hypermiling game

電動車完全改變了超節能比賽，

as drivers compete to travel the farthest on the fewest kilowatt-hours.

比賽規則是用最少的能量 （千瓦時）行駛最遠距離。

And records will likely only get more impressive,

說不定比賽的記錄只會 越來越讓人歎為觀止。

as the design of EV motors allows for the introduction

因為電動車馬達的設計

允許引進創新的節能裝置。

of innovative energy-saving devices.

For example, most EVs utilize regenerative braking,

例如，大部分電動車 都使用再生煞車，

where energy normally lost to friction is conserved.

將通常會因摩擦 而損失的能量保留下來。

As the car slows, the electric motor operates in reverse,

隨著車速減低， 電動馬達會朝反方向運作，

capturing the vehicle’s kinetic energy to recharge the battery.

捕捉該車的動能來為電池重新充電。

Some companies are even equipping EVs with rooftop solar panels,

有些公司甚至在電動車上 加裝屋頂太陽能電池板，

further increasing their range.

進一步增加車輛能行駛的距離。

Since they don’t burn fuel, EVs have zero tailpipe emissions.

因為電動車不燃燒燃料， 所以不會排放任何廢氣，

That’s not to say they’re always carbon neutral.

但這不代表電動車都有達成碳中和。

EVs require regular charging of their batteries,

電動車的電池需要充電，

meaning their emission profile is only as clean

也就是說，它們實際排氣量有多低，

as the electric utility they plug into.

就要看供電給它們的電力公司了。

So as global grids continue to shift towards renewable sources,

因此，全球電網陸續轉型至再生能源，

EVs are also becoming greener,

讓電動車也變得更環保，

making them an even more attractive, hyper-efficient option.

成為更具誘因的超高效率選擇。