Best Impact Wrench For Automotive Work and the right sizes

by Joost Nusselder | Updated on:  March 12, 2022
I love creating free content full of tips for my readers, you. I don't accept paid sponsorships, my opinion is my own, but if you find my recommendations helpful and you end up buying something you like through one of my links, I could earn a commission at no extra cost to you. Learn more

In order to complete automotive work properly, you’ll need an impact wrench of the right size. When working with automotive tasks, however, you may feel confused and wonder what size impact wrench would be best for the job.

However, you should actually consider various measurements like torque, power supply, etc., along with its driver size for choosing a suitable impact wrench. We, therefore, are here to alleviate your stress through our article and to offer guidance so that after considering all of these factors, you can find your best fit.


Impact Wrench Types

If you want to use an impact wrench for your car, a power source is a must. So, the best thing to differentiate between impact wrench types is their power source. After categorizing this way, you will find two major types called pneumatic and electronic.

The pneumatic impact wrenches are also called air impact wrenches, and they run using the airflow of an air compressor. Needless to say, most pneumatic impact wrenches have enough power to be used for automotive work.

Another type which is called the electric impact wrench, has two variants called corded and cordless. The corded variant needs direct electricity to run the impact wrench, and a cable line from the impact wrench should be connected to the electrical outlet. On the other hand, you need lithium-ion batteries to run the cordless version. Gladly, both of these versions support enough power to perform automotive tasks.

Required Torque For Automotive Work

Torque is the most important thing when you are removing a nut or bolt using an impact wrench. Because the whole mechanism of the impact wrench is based on this single physics. If an impact wrench does not provide enough torque to tighten or loosen the nuts, you won’t get enough impact force to work with the automotive.

After taking the exact measurement, we’ve found that the average torque required for automotive work is about 1200 ft-pounds. We think that this torque range is enough for all kinds of substantial automotive tasks too. However, our suggestion is to set the exact torque based on your operation. Because you don’t need the highest torque all the time. So, remember the truth, most people use more torque than the needed level due to unawareness and damage to their nuts day by day.

Impact Wrench Size For Automotive Work

In the first place, we should confirm that the most common nuts a mechanic needs to face when performing automotive tasks are the lug nuts. Because a car is mainly built using these nuts. And, you need a proper fit to work with these nuts.

Primarily, there are two sizes of impact wrenches that can fit for automotive work, which are 3/8 inch and ½ inch. Both of these two sizes come in the same format in the socket, and that’s why you can use them both in any case. We are pretty sure that these two sizes can cover 80 percent of the overall automotive work.

Never forget that there are always some exceptions. Though a ½ inch impact wrench will cover most of the tasks, it won’t be enough for a large car or truck. In such a condition, you will need bigger impact wrenches like ¾ inch or 1-inch models to perform heavy tasks. You can easily get enough torque from these impact wrenches.

When Choosing Air or Pneumatic Impact Wrench

You know that air impact wrenches run using airflow-based power. And, you will be glad to know that you can easily buy this option without spending much. Besides, you can easily complete most of your automotive tasks as you will get high torque from this option.

The negative side of an air impact wrench is that you cannot move it easily from one place to another. And, that’s why it is a preferable option if you are thinking of using an impact wrench in your garage and don’t need to move often. If we look at the positive side, you won’t find any malfunctioning problems as it doesn’t have any electric parts. For the same reason, it doesn’t get overheated.

When Choosing Corded Electric Impact Wrench

When you need maximum torque in your automotive tasks, you can use a corded electric impact wrench. Since it runs using direct electricity, you will be able to get the highest speed from this tool. So, we can suggest it as the best choice if you want to work professionally in this sector.

Specifically, the corded electric impact wrench is designed to complete the toughest jobs effortlessly. For this reason, you can work with trucks and large cars using this impact wrench. Additionally, its automatic function will allow you to accomplish the operations smoothly without any hassle.


When Choosing Cordless Electric Impact Wrench

Convenient is the best word that suits this electric impact wrench. Because, you are free from any disturbance created by cables or additional power sources. You just need to put single or multiple batteries inside, and the tool is ready to rock on.

The cordless type is popular for its portability and ease of use. Removing or tightening nuts in tight areas seems pretty easy because of its capability of free movement due to its small size. Luckily, nowadays, some cordless impact wrenches come with such functionality that these impact wrenches can handle tough jobs, just like the corded version.

The Bottom Line

So, what impact wrench size is suitable for automotive work? Now, you’ve got the answer. To be specific, you need 3/8, or ½ inch impact wrenches for most jobs. And, sometimes, you may need the ¾ or 1-inch impact wrenches for the toughest jobs. In any case, follow the precautions above to get the best result.

I'm Joost Nusselder, the founder of Tools Doctor, content marketer, and dad. I love trying out new equipment, and together with my team I've been creating in-depth blog articles since 2016 to help loyal readers with tools & crafting tips.