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How much oil does a 18 wheeler take

April 20, 2022

how much oil does a 18 wheeler take

How much oil does an 18 wheeler take is something every truck driver needs to know. Engine oil is a critical component. It’s not cheap, and it doesn’t last forever. You’re going to have to change the oil on your 18 wheeler, so you need to know how much oil an 18 wheeler takes.

How Much Oil Does An 18 Wheeler Take

It varies a bit, but in general an 18 wheeler takes at least 15 gallons of oil, if not more. To put that in perspective, the average car or truck holds 4-6 quarts, or about 1 gallon of oil. That’s a lot of engine oil, but it’s essential to the functioning of your engine.

Maintaining proper oil levels will extend the life of your 18 wheeler engine, and it will actually lower your overall maintenance costs. So, while it might hurt a bit to pay for 15 gallons of oil each time you need an oil change, just remember it’s a lot cheaper than what you’d have to pay if you drove your 18 wheeler without enough oil.

18 wheeler oil change

How Often Does An 18 Wheeler Need An Oil Change

In general, an 18 wheeler needs to have its oil changed every 25,000 miles. That sounds like a lot, but remember that it’s common for an 18 wheeler to be driven 100,000 miles or more in a year. That means you might be changing the oil four times each year. The exact frequency depends on how much oil an 18 wheeler takes, so it might vary from one model to another.

Believe it or not, that’s actually a big improvement. Advances in both engine design and oil technology have improved performance. 18 wheelers used to need oil changes a lot more often. So the good news is that as they keep making improvements, you may be able to go even longer in between oil changes.

oil is important for 18 wheeler

What Kind Of Oil Does An 18 Wheeler Engine Use

You definitely can’t put the same oil in your 18 wheeler that you would put in your car. But they are similar, and like your regular motor oil, an 18 wheeler can take natural or synthetic oils. One you know how much oil an 18 wheeler takes, you need to make sure you’re using the right kind of oil.

15W40 oil was the gold standard for 18 wheeler engines for a long time, but 5W40 has grown in popularity since it functions better in cold weather. 5W40 is widely considered to be less protective than 15W40, so a lot of truckers still use 15W40 oil.

That said, different engines are designed for different oils. Some 18 wheeler engines need 10W40, and some won’t work at all with 5W40. Always check the manufacturer specifications to see which oil your engine needs.

Which Type of Oil Is Best?

Just like with your car engine, you can choose between natural and synthetic oils. Natural oil is just mineral oil, and it’s usually much cheaper. Synthetic oil has to be manufactured, so it’s much more expensive. Given how much oil an 18 wheeler takes, the cost of the oil adds up fast.

For short trips, you can save some money and use mineral oil without any issues. It will protect your engine well and can work just fine in a wide range of temperatures. Since it’s quite a bit cheaper than synthetic oil, a lot of drivers will use natural mineral oil when they know they’re going to be driving shorter routes.

When To Use Synthetic Oil

Synthetic oil is more expensive, but for good reason. Synthetic oil performs a lot better than natural oil. It’s more pure, so it forms less sludge in the engine. It handles an even wider range of temperatures, and it doesn’t degrade as quickly. That means you can get more mileage out of synthetic oil than natural oil, without risking damage to your engine.

However, since it is more expensive, it’s best to wait until you have a long trip ahead of you to pay the extra cash for synthetic oil. While it certainly performs better, and lasts longer, you won’t actually reap those benefits except on longer trips. So, wait to buy the synthetic oil until you really need it.

mechanic changing oil on a 18 wheeler

How Long Does It Take To Change The Oil In An 18 Wheeler

This can vary a lot. It all depends on the specific vehicle, and where you take it to have the oil changed. It can be anywhere from 15 minutes to 45 minutes. There’s definitely no such thing as a 5 minute oil change with an 18 wheeler.

If you do it yourself you’re looking at 30 minutes to an hour to get it done properly. Most drivers are happy to let someone else handle that job.

How Much Does It Cost To Change The Oil In An 18 Wheeler

If you’re lucky, you might find a place that can change your oil for about $200. Most of the time, though, expect to spend $350-$400. Frankly, considering how much oil they use, that’s a much lower cost than you might expect.

And, when you consider how much damage can be done by not changing your oil regularly, it’s a small price to pay. By spend a few hundred dollars on an oil change, you’re saving yourself thousands, at least.

Why Does The Oil In An 18 Wheeler Have To Be Changed

Oil seems like a pretty durable product, and it’s in a closed system. So why does it have to be changed at all?

Oil Degrades In Your 18 Wheeler

One of the main reasons you have to change the oil in your 18 wheeler is that it breaks down and degrades over time. It’s exposed to a lot of heat and friction, which slowly damages it. As it breaks down, it doesn’t function as well as it should.

Eventually, the oil will break down to the point that it no longer functions at all, and that’s when your engine starts to suffer damage. Oil is a very durable product, but it’s exposed to some incredibly harsh conditions.

oil can get dirty in 18 wheeler

Oil Gets Dirty in An 18 Wheeler

As an 18 wheeler drives along the highways, they pass through a lot of dust and dirt. The engine does need air to work, so it has air intakes that are constantly bringing air, along with dust and dirt, into the engine. While it also has an air filter, that won’t keep everything out.

A lot of that dirt gets trapped in the engine oil. Over time, the oil becomes very dirty. This is why used motor oil is dark brown or black, and new motor oil is a golden, clear color. As the oil gets dirty, it’s harder to keep it circulating through the engine.

Just like your car, your 18 wheeler engine does have an oil filter that removes a lot of that dirt, but it also has its limits. That’s why you’ll typically change the filter each time you change the oil.

O​il Burns In Your 18 Wheeler

Diesel engines get hot when they’re in use. After all, they’re literally burning fuel, and they’re made of metal which conducts heat. So, the entire engine heats up, and so does everything in direct contact with it.

That includes the oil you use. While motor oil is made to stand up to extreme temperatures, it has its limits. As you drive, the oil is continuously circulated through the engine to help keep it from getting too hot. Still, there’s really nowhere for the oil to cool off.

Eventually, the oil is going to burn. Fortunately, oil is so resistant to extreme temperatures that most of it will be fine. It’s common, though, to lose about a gallon of oil between oil changes as the engine burns through it.

This is one reason why synthetic oils tend to be better for long distance travel than natural oils. They stand up to high temperatures better, and therefore they burn less.

What Does Engine Oil Do In An 18 Wheeler?

We’ve stressed the importance of engine oil, but we still haven’t talked about why engine oil is so important in an 18 wheeler. It performs all the same functions as the oil in your car does, but the conditions are harsher.

Engine Oil Is A Lubricant

An 18 wheeler engine has a lot of moving parts, and they’re all made of metal. For those parts to work properly, they need lubricant. They’re constantly sliding against other metal parts, and without lubricant that would generate a lot of friction, which would impair movement and create additional heat.

Engine oil is pumped around the engine. lubricating all the moving parts to minimize friction. This is it’s most important function. Without lubricant, the engine will seize up and shut down. The damage caused by that would be extensive, and repairing it would be very expensive.

Fresh, clean oil is the best lubricant, which means it enables those moving parts to work at their peak efficiency. This leads to better engine performance in addition to reduced maintenance costs.

Oil Keeps Your 18 Wheeler Engine Clean

We’ve already mentioned all the dirt that gets trapped in motor oil. This is actually part of the function of motor oil. The oil is essentially washing away the dirt and debris that gets sucked into the engine.

If the dirt wasn’t washed away by the oil, it would be stuck in your engine. That would get in the way of your engines proper functioning. It would prevent moving parts from moving, and it would cause the engine to seize up and shut down.

By washing away the dirt and debris that gets into your engine, oil performs a vital function that extend the life of your engine.

Oil Improves Your 18 Wheeler Gas Mileage

We’ve already discussed how motor oil keeps your engine functioning at peak efficiency. By lubricating and cleaning all the moving parts of your engine, motor oil ensure that everything is working smoothly.

When that happens, most of the energy created from burning fuel gets transferred into the drive shaft. That’s because it isn’t having to overcome a lot of friction in the engine itself. In other words, it takes less fuel to move your 18 wheeler when the oil is clean and you change it regularly.

You might not like paying for each oil change, but it’s going to save you a lot of money at the gas pump.

How To Know When To Change The Oil In An 18 Wheeler

While the rule of thumb is to change your oil in an 18 wheeler every 25,000 miles, it’s good to know the signs that you need an oil change. You made need to change if before you hit the 25,000 mile mark. Or, you might just forget when your last oil change was. Luckily, there are a few easy signs that let you know it’s time for an oil change.

The Check Engine Light Is On

Just like your car, the check engine light in your 18 wheeler will come on if the computer senses a problem with the oil. There might be other reasons for that light to come on, so you should get it checked out to be sure that the oil is the only problem.

Needing an oil change is a common cause for check engine lights, but not the only one. And some of the problems that might trigger that light can also cause you to burn through your motor oil faster, so changing the oil may not always solve the problem.

Oil Level Is Low

One key to the proper maintenance of an 18 wheeler is to check the oil level regularly. The process for this is just like checking the oil level in your car. Take the dipstick out, wipe it off, and stick it back in the reservoir. Then pull it out again and check the oil. It is not only important to know how to drive an 18 wheeler, but also how to take care of one.

If the oil level is too low, or the oil is dark and dirty, it’s time for an oil change. You should check your oil levels before every trip. 18 wheelers go through motor oil a lot faster than your car does, and you don’t want to take any chances.

Engine Noise

Experienced truckers can tell by their engine noise if they need an oil change. Since the oil in an 18 wheeler is what keeps everything lubricated and moving smoothly, it quickly becomes obvious when it’s not working as intended.

The engine will be louder and will sound rougher. It will take some time for you to be able to notice these different sounds, so don’t rely on engine noise if your new to this job or if you’re in a new 18 wheeler.

Smoky Exhaust

An easy way for even beginners to tell if they need an oil change is if there’s smoke in the exhaust. Your 18 wheeler has exhaust pipes to carry vapors and fumes out of the engine. Normally, these shouldn’t be visible.

If there’s noticeable smoke in your exhaust it’s a sign that your oil is dirty, burning, and in bad need of a change.


It’s important for every truck driver to know how much oil does an 18 wheeler take. Make sure you know how much oil you need and can spot the signs that you’re in need of an oil change.

About Booker Transportation

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