Mack E7 Engine Specs: What To Notice?

Mack E7 is one of the most common engines you can find now. It is an inline six-cylinder, heavy-duty one that appears in a variety of car models.

And certainly, if you are interested and want to learn more about this motor, then the Mack E7 engine specs are what you should not ignore.

That is also what I will share, according to my knowledge and experience, in the next sections!

Mack E7 Engine Specs 

mack e7 engine specs

The Mark E7 is a 12L 6-cyl engine with 4 cycles; with a displacement of 728 cu in, it can churn out 250 to 454 HP and 975 ft-lbs to 1,660 ft-lbs.

There are also many technologies equipped in this engine.

There are some need-to-know aspects about the Mack E7 460, Mack E7 427, or Mack 350 engine below.

Mack E7 Engine History

The engineers of the Mack Corporation first conceived of the E7 Mack engine in 1988, and it was first made public in 1989.

The long-running Mack E6 model, which was produced for more than 20 years, was replaced by the E7.

Because of its dependability and fuel efficiency, it was popular with both large and small companies. As of 1999, the manufacturer eventually produced 16 different variants of the E7.

Its technology has a stellar reputation for having an excellent horsepower-to-weight ratio. As per the Mack E7 torque specs, it has six cylinders and multiple cooling systems.

Engine Introduction & Data

The 6-cylinder, multi-system cooled E-Tech engines have a wide power range. The fuel injection system uses the V-Mac III electronic fuel control system.

This is an advance on the Econovance technology of the E7 that made use of electronic unit pumps.

The Mack E Tech motor also employs high swirl combustion to improve fuel efficiency and pollution.

According to the E7 Mack engine specs, the E-Tech has a 34-quart dual-flow paint-on oil lubrication system.


The original E7 had an air-to-air after-cooled system and was turbocharged.

In 1990, the manufacturer created the Econovance Variable Injection Timing system, a variable-injection timing one that improved fuel economy and decreased pollution.

The High Swirl/Moderately High Injection Pressure Combustion System was another addition made to the E7 by Mack in 1991.

This improved oil change intervals and reduced pollutants and oil viscosity while enhancing combustion efficiency and fuel economy, with the Mack E7 oil capacity being 34 quarts.

Power Specifications

The E7 is a four-cycle, 12L, direct-injection motor with a 728 cu in displacement. The E7’s maximum output ranged from 250 to 454 HP at 1,700 rpm – 1,800 rpm.

Its torque in the 250-HP spec was 975 ft-lbs @ 1,200 rpm. It is 1,160 ft-lbs @ 1,200 rpm in its 300 horsepower specification.

With Mack E7 engine torque specs with 350 HP, torque increased dramatically to 1,360 ft-lbs. The 400-horsepower model’s maximum torque was 1,460 ft-lbs @ 1,250 rpm.

At 1,200 rpm, the E7 will pump out the  maximum output of 454 HP and 1,660 ft-lbs of torque.


Most motors still in use today are later variants that are water-cooled. Many believe Mack changed its design to comply with the criteria set by the Environmental Protection Agency for emissions.

New redesigns have been implemented to comply with EPA requirements since 1990.

The Econovance system wasn’t used on any other production lines but only on the E7.

In addition to the Econovance technology, Mack also made changes to its E7 line that enhanced the efficiency of the fuel/air mixing ratio by using a high-injection pressure combustion system.

It’s called “swirl technology” that significantly boosted airflow.

Application & Uses

As mentioned above, this is used in different fields and industries; some of the typical ones include:

  • Oil & Gas 
  • Mining
  • Industrial 
  • Agriculture 
  • Construction 

Replacement Options

Many things might hurt your engine, and in some cases, your engine is beyond repair.

Your E7 may occasionally only require a few new components or may only require minor maintenance to stay in good shape.

Choosing a completely new engine will guarantee performance and warranty but will be more expensive than used ones.

Mack E7 Engine Common Issues 

350 mack engine specs

Odd Noises

One of the most common issues you may face with the Mack E6 engine or E7 engine is the odd noises.

When running, a semi-truck motor is expected to create noise.

However, you should pay attention to the sound you hear because a loud, continuous knocking sound or a lawn-mower-like noise is abnormal.

It can indicate that its component is experiencing wear and tear or a problem with the combustion timing or oil pollution.

Colors Of Exhaust

Keep an eye on the exhaust color since they reveal a lot about the health of your Mack E7 500HP engine.

For instance, while the typical hue is gray or white, black or blue exhaust indicates oil problems.

Sometimes, I even notice white smoke smelling like gas rather than darker colors. The weird odor is also a typical sign.

The deeper color of your exhaust may also indicate a problem with your injectors, cylinder liner, or piston rings. To fix the issue properly, you would need to get your motor evaluated by a mechanic.

Engine Performances

When you observe certain changes in how your motor is operating, that could also be a clue that there are issues.

If you discover your truck is not performing as well as it once did or its speed has significantly diminished, you should investigate the potential causes carefully.

Additionally, make sure the Mack diesel engine brake is working properly by checking it. It can be risky to keep driving if this component has problems.

A loss of cylinder engine compression or a problem with your valves, head gasket, or piston rings typically brings on this problem.

Fuel Economy Loss

Another of Mack E7 engine problems is fuel refilling more frequently, indicating that it is running less efficiently.

You can be losing fuel economy because your injectors are worn out or damaged. Any changes or variances in the gas mileage must be carefully observed.

Low Oil Level

Do you have to top off the engine oil more frequently along with experiencing decreased fuel economy in the E7 or E6 Mack engine?

If this is the case, an oil leak can exist and must be fixed. This issue may occasionally stem from problems with your cylinder liners and piston rings, which must be inspected.


e7 mack engine specs

What HP Is The E7 Mack Engine?

This engine typically produces between 250 and 454 HP. It can produce  975 ft-lbs of torque at its lowest power setting of 250 horsepower. 

It can have a maximum of 454 horsepower and a strong 1,660 ft-lbs of torque.

Is Mack E7 A Good Engine?

Yes, it was one of the most well-known commercial diesel engines ever. Its dependability and fuel efficiency are trusted by many large and small companies.

The engines were renowned for having an excellent horsepower-to-weight ratio. Its E-Tech motor also employed high swirl combustion to improve fuel efficiency.

What Are The Differences Between Mack E7 And Mack E6?

A wide power range and ability to produce maximum power at the controlled speed are two features of Mack high-torque engines.

The 672 cu in (11 L) inline six-cylinder Mack E6 was turbocharged. It produced 200 to 350 HP.

Meanwhile, the E7 is a 728 cu in (11.9 L) inline six-cylinder turbocharged engine, generating 250 to 454 HP.

Bottom Lines 

You’ve got all the need-to-know information about Mack E7 engine specs. Although there are still some problems that you may face, it is the most common and popular type in the market.

The manufacturer always focuses on new versions, so the experience and performance will also improve gradually.

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