Semi trucks are a vehicle we see almost every day. Many young kids are fascinated by the “big cars.“但普通人可能对半挂车了解不多. 例如，你可以称它们为牵引拖车、18轮车或卡车. 在这个博客中，我们将回答你所有关于半挂车的基本问题.

What is a semi truck?

半挂车是一种用于运输大货物的重型卡车. Technically, they’re Class 7 or Class 8 vehicles. For comparison, 你看到的拉着露营拖车的大皮卡通常是2b级或3级车辆, sometimes Class 4. 

Why do they call it a semi truck?

It’s actually a bit of a mistake to call the truck a semi. The term originally referred to the trailers. 因为拖车没有前轮，所以严格来说它们不是拖车. So they were called semi-trailers. 随着时间的推移，人们开始把卡车-拖车组合称为半挂车，然后只是卡车. 

There are tons of other common names for them as well. 18- wheeler是最受欢迎的一种，指的是半挂车在拉动拖车时通常有18个轮子. Tractor-trailer is also another term you may hear a lot. 所有这些名字都是指卡车和拖车的组合, 尽管他们通常只和卡车部分联系在一起.

What kinds of semis are there?

你可以把卡车分为两类:卧铺和日间驾驶室. 卧铺用于长途卡车运输，因为它在卡车的后面有一个卧室隔间. 卧铺可以非常简单，只有一张单人床和一些储物空间. Or they can get pretty fancy with two beds, a minifridge and microwave, TV and surround sound, and more! That may sound like a lot for a truck, 但司机可以在卡车里住上一周或更长时间, 只在上厕所和加油的时候出来.

A day cab is just a big truck without the sleeping area. 这些卡车用于短途运输，司机可以在轮班结束后回家. 你经常在配送中心、港口甚至机场看到日间出租车. 在货物运输量大的地方，你经常会看到白天的出租车.

The Different Categories of Sleepers

You can have high-roof, mid-roof or flat roof trucks. 高顶卡车有尽可能高的车顶，给司机足够的空间站起来. High-roof trucks can be over 8 feet high inside. Mid-roof trucks are usually around 6 ft 9 inches inside. Flat-roof trucks are around 5 feet tall inside. 这些特点决定了司机在卡车里生活时的舒适程度, 也会影响你用卡车能拉的东西和你能去的地方. 低矮的桥梁、隧道和其他道路特征意味着高大的车辆无法在一些道路上行驶.

How much does a semi weigh?

根据卡车的品牌和型号以及卡车的发动机，这个答案会有很大的不同. 日间出租车(没有床的出租车)的重量一般在15-16磅左右,000 pounds, around the same as two adult Asian elephants. 小型卧铺(平顶的那种)要贵1000英镑左右. That’s like putting a polar bear on those elephants. Large sleepers can weigh over 18,000 pounds.

Do they use a tow hitch?

Nope! The trailer attaches to the truck with a large pin, called a king pin, 那通常是2-3英寸厚，从拖车的底部伸出来. Imagine a water bottle-sized solid steel pipe. The king pin goes through the fifth wheel, 卡车后面有一块马蹄形的大金属片, and clamps lock it in place. 两个小挂件根本拉不动一整辆拖车. 第五个轮子也带来了拖车前半部分的重量正好超过后轮, making it easier to pull tall, heavy trailers.

How much does a semi cost?

与重量一样，价格也会根据卡车的种类、发动机和其他特征而变化. New semis generally start above $100,000, but with more features on larger trucks, the price can get close to $200,000. Used trucks can be a great way to get a good truck at a lower price. Those are generally priced lower around $40,000-70,000. 但根据行驶里程的不同，价格可能会更高或更低, condition, age, make and model, and features of the used truck. 对于老式或高里程卡车，有些可能低至1万美元.

想了解更多关于购买过程的信息? Check out our buying guide for used semi trucks.

How tall are they?

Semi trucks are between 6.5 and 10 feet. 高度取决于卡车是在卧铺上有一个较高的车顶，还是有一个车顶帽. 车顶盖是一个弯曲的部分来在卡车的车顶，使其更符合空气动力学. Many day cabs have tall roof caps, 使空气能够顺利地从卡车前部流过，穿过拖车的顶部.

How much weight can a semi truck pull?

They pull anything over 26,000 pounds. 但许多卡车的最大重量实际上是道路重量限制. 在每个州，8万磅是所有车辆的限制. That’s the equivalent of 26 Prius cars! The weight also depends on the type of trailer. 

What kind of trailers can they pull?

干货车拖车是你在路上看到的典型的矩形盒子. 它们被用来运输许多消费品，比如衣服、玩具、电子产品、书籍等等. 

Refrigerated vans, or reefers, look like dry vans, 但他们在拖车前面装了个大冷藏箱. 它们被用来运输需要冷藏的食物，比如肉、奶酪和冰淇淋. 

Then, there are flatbed trailers 它可以是一个平坦的基座，也可以是一个大台阶，叫做drop deck或step deck. 它们被用来运输不需要挡风遮雨的大型物品, or things that don’t fit in a van. 

Another type of trailer is a tanker. There are lots of kinds of tankers. 有些是从后面空的，有些是从下面空的，有些是从上面空的. They can carry all kinds of liquid like milk or oil, 但它们也被用来运输小麦和豆类之类的东西. 

The last common type of trailer is a car hauler. There are open and enclosed car haulers. 开放式汽车搬运车更常见，用于将汽车从港口或工厂运送到配送点或经销商处. 封闭式汽车拖车保护汽车免受道路上的任何损坏, 所以它们更多地用于非常昂贵的汽车或定制汽车, like racecars.

What’s the best truck brand?

Well, that’s hard to say. As an authorized Mack and Volvo dealer, 我们认为他们是目前市场上表现最好的半轮车之一. 但“最好”的卡车往往是基于意见和确切的应用.

So, those are the basics! You’re always able to 浏览我们的大型库存新的和使用的半卡车出售. We always welcome questions, so find us on social media!