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Do Semi-Trucks Have Turbos? (11 Facts You Should Know)

There are no doubts turbos make driving more fun and with the huge engines trucks have, they make life a lot easier.

But do all Semi-Trucks have turbos?

Here we’ll explore which ones do and which don’t as well as how beneficial turbos are to the life of a truck and the driver.

Here’s a Quick answer to Do Semi-Trucks have Turbos?

Semi trucks have turbos however, you may find older semi trucks without a turbo or with one that has been removed. Semi truck engines these days have turbos factory fitted. Turbos help by giving the trucks more power, while being more fuel efficient. They also play a role in reducing emissions.

Do Semi-Truck Engines have Turbos?

Not all Semi-Trucks have turbos. In the older models you will find that some don’t but in the current market it is a common thing to have a turbo.

This is because engines in modern times would simply not have the power required of them to carry out their day to day tasks.

The older diesel engines rely on air pressure from their surrounding atmosphere which as you can imagine makes them a lot weaker.

In the mid-1950s the turbo diesel Semi-Truck engines became available on the market and cause a stir.

MAN MK26 was unveiled in 1951 followed by the first production release of the MAN 750TL1 turbo diesel and the Volvo Tiitan turbo in 1954.

This in turn grew the demand for more turbo truck engines.

How Do Turbos Work in a Semi-Truck?

A turbo on a truck is designed for more fuel efficiency.

In the inner housing you have the compressor wheel and the turbine wheel which are surrounded by the housing.

The exhaust gas produced by the engine is forced through the turbine inlet creating kinetic energy. This spins both the wheels at the same speed.

The compressor wheel draws in air and compresses it (squeezes it in) then pushes it through the outlet supplying more air to the engine.

This is hugely beneficial to a truck due to the turbo pushing hot compressed air through the intercooler allowing more oxygen to reach the engine making it more efficient and can reduce fuel consumption by up to 20%.

The turbo as we all know creates more power which is much needed to get the truck up that hill and help ease the strain on the engine when hauling a load.

How much Horsepower does a Turbo Add?

A typical turbo on a semi-truck can add around 15% more horsepower to the engine. This is calculated by the power required to pull 550 pounds one foot in one second.

To measure this you would need to run an engine with a dynamometer attached before and after the turbo is introduced, and work out the difference from there.

A twin-turbo would increase your horsepower twice as much with a lot more airflow, however, this does produce more heat and backpressure.

Most truck drivers prefer a single turbo.

Horsepower is really just a calculation of torque x Rpm.

Which Semi-Trucks have Turbos and which Don’t?

It is very difficult to find a semi-truck without a turbo unless you go way back to the earlier years.

However even older semi trucks have had turbos fitted to improve airflow to the engine and reduce fumes out of the exhaust.

Diesel turbos are common in 99% of semi trucks these would be as follows:

  • International lonestar.
  • Volvo VNL models.
  • Freightliner cascadia.
  • Mercedes Actros.
  • Freightliner 122SD.
  • Kenworth W990.
  • Scania R models.

The list goes on for the semi trucks that has a turbo but you may get stuck in finding one without.

Our research came up with this:

  • Nothing.

The reason for this is that all manufacturers have to comply with emissions regulations.

Combining that with new diesel turbo engines and the laws surrounding how old a truck can be, its kind of phasing them out making them very hard to find.

As trucks generally do long haul, diesel is the better option when compared to gasoline and has won 1st place.

The conversion from gasoline to turbo diesel has been going on since the 1960s, which is why you would struggle to find one today.

Which Semi-Truck Engines have the Best Turbos?

Leading the market for their innovative designs in their turbos most semi-trucks are using a bulldog big rig stage 2 caterpillar turbo used by top brands such as Peterbilt, Kenworth, and Freightliner.

Holset which is part of Cummins, supply turbos to Volvo, Iveco, Detroit diesel, and Scania to name a few.

Truck manufacturers like to stick to what works for them in terms of firstly cost and secondly the quality of a product.

They look at the durability of the materials the turbo is made from and its efficiency in performance.

They always set out to improve engine components to reduce costs and improve on a more comfortable ride as well as profits.

How many Miles do Turbos in a Semi-Truck Engine Last?

Nowadays a semi trucks turbo can last the lifespan of the truck itself, provided nothing goes wrong with it and it doesn’t take too much unnecessary punishment.

The engine and turbo work together. If you neglect the engine or it goes bad, it will also affect the turbo at some point.

A turbo at a good range can last from 150,000 to 400,000 miles.

95% of the time the turbo will be fine but always have it checked out by a professional.

What tends to usually go wrong is the actuator which acts as a pressure relief valve and controls the boost output diverting excess exhaust gas away from the turbine wheel.

This prevents it from over speeding and helps regulate the compressor speed.

How do you know if your Semi-Truck has a Bad Turbo?

Your truck will usually have a warning light eliminate on the dashboard in the shape of an engine.

You will also notice the truck becomes more sluggish with a louder acceleration and it will struggle to stick to high speeds.

A bad turbo also has the appearance of blue/grey smoke coming from the exhaust.

A certain lack in the throttle, as well as lower rpm, is another sign of turbo trouble.

If you don’t mind getting your hands dirty you could remove the air filter housing and without touching the blades check the inner wheel (compressor).

Make sure it doesn’t have too much play side to side to in and out. Check for kinked pipes which will interfere with the oil flow.

Check for excessive oil on the blade. This could mean the seal inside the turbo on either side has got loose or broken.

The top of the sleeper will be covered in oil from splashback and wind the intercooler also may have unusual amounts of oil on it.

Can you Fix a Bad Turbo in a Semi-Truck?

It is possible to fix a bad turbo depending on how bad it is and if it’s more cost-effective than buying a new one.

If so you should have it repaired or reconditioned.

Before you go ahead and fix or change anything be sure to do a thorough investigation to pinpoint the cause.

It could be a simple fix like reattaching a duct or a very complicated procedure like removing a broken blade that has made its way to your engine.

Some things may be visible without removing any major parts but some aren’t so easy.

Just remember the inner wheels of the turbo are the fastest moving components in your vehicle and require your love and attention.

How Much does a Turbo Cost for a Semi?

A caterpillar stage 2 big rig turbo comes in direct from bully dog at $2000.

A Cummins Holset ISX Turbo comes in at $3500 on ebay, but this is a rebuilt turbo and hardly worth it seeing as you can get a brand new one for $1500 less.

The point is to shop around and not just jump on the first one you find, but also be 100% sure it is a fit for your engine.

Although I’m pretty sure you can return something like that so don’t worry too much.

Remember to add labor costs to your new or used turbo unless of course your doing it yourself.

These figures come in at $400 to $600 excluding taxes but may vary depending on the truck.

You may be thinking of buying the part yourself and then taking it to your mechanic.

However, this will not save you money as the mechanic already gets the part at a trade rate then adds their fee on top of that.

Also, your mechanic probably won’t cover the turbo if it goes wrong or needs a service.

So unless you can get it at trade price it’s best to just leave it to them.

How to Prolong the Turbo Life in your Semi-Truck?

The main thing to prolong it’s life would be the skill of the driver (you).

By planning the road ahead will reduce the amount of strain the engine and it’s turbo will go through.

If you stall, fire it up asap to keep it lubricated or the oil stops pumping and you’ll dry start (not good).

Perform regular checks on the entire truck. A low pressure on a tire might not seem much but can lead to strain on the engine which in turn could affect the turbo.

This may not happen straight away but over time these little things add up.

Check all your fluid levels on regular basis (every few days).

If you feel some performance issues, using a turbo cleaner spray into the air intake.

First run the engine for five minutes. Whilst running spray in short intervals until the can is empty. Then leave the engine to run a few more minutes and then turn it off a few minutes.

Restart the engine and accelerate to 3000 rpm to push the fluid through the turbo. Some sprays may vary so read the advice on the can.

What are the Pros & Cons of Semi-Truck with Turbos?

The pros are that you save on fuel whilst you have more power which makes your life easier.

The cons are more things to go wrong and more expenses if it does go wrong.

However, I think it’s safe to say as long as you follow our guide on prolonging the life of your turbo then the pros will outweigh the cons.

Performing regular maintenance on your semi truck will keep it working in an optimal condition, and save you money in the future.

Happy Trucking!

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