So, can an electric impact wrench remove lug nuts? Yes, a good quality electric impact wrench will have a nut-busting torque in the range of 500 – 700 ft-lbs. More than enough to cope with auto lug nuts.
In this post I’ll cover the cordless impact wrench I’d buy and why.
The main advantage of the cordless operated torque wrench is pretty obvious – its mobility. Having all that torque in the trunk of your car could make you feel like a Nascar pro.
Car lug nuts are supposed to be torqued to about 100-120 ft-lbs, but too often even the pros won’t take out a torque wrench, instead, they’ll sow them on with an impact, set a lot higher than 100 ft-lbs.
But, it’s not always the mechanic’s fault, over time, corrosion, road salt, and debris can cause the lug nuts to become stubborn.
Of course, you know nothing about this, until you’re on the side of the highway, likely waiting for a tow truck, because you’ve got a flat and a broken tire iron.
I try and avoid these types of dramas by cleaning off my lug nuts using a wire brush and using copper grease on the hubs. I re-torque my wheels after it’s been in a tire shop unless I see them use a torque wrench.
Sometimes an incorrectly tightened wheel can cause an imbalance, it’ll feel like a wheel weight has fallen off. The fix is to back off the lug nuts and torque them to spec, in a star pattern sequence (tighten lug nuts opposite each other).
Often I find classic car owners use copper grease on the lug nuts, and while I understand the motivation, it’s actually not a good thing.
A torque wrench operates by sensing the friction tension of the fastener threads. Any lubrication will reduce the friction which will cause the torque wrench to over tighten the lug nuts.
The Impact Wrench I’d Buy
I don’t own a cordless impact wrench yet, but I know the one for me, it’s been on my birthday list for a while. I’ve been using impact wrenches for about twenty years and I like to think I know what makes a good one.
The battery-operated impact I’d buy is the DEWALT 20V MAX XR Impact Wrench.
And the reason I’d buy this one – It’s dependable, compact and has just the right balance of power for the intended purpose.
A really nice feature is the LED lights, save you struggling in the dark or trying to balance a flashlight on the work zone, I’ve been there.
Having good quality tools that you can rely on is important, especially in an emergency. Dewalt builds a super tough kit, in fact, Dewalt says this model can withstand a six-foot drop, I’ll take their word.
This impact wrench isn’t cheap, but I think of it as an investment, it’s a wrench you’ll have for years and years.
Performance – What’s Under The Hood?
Performance means power and the Dewalt has plenty, more than enough to unzip lug nuts.
As you know, lug nuts should only be tightened to about 100-120 ft-lbs (trucks about 150 ft-lbs), but very often they’ll be a lot tighter.
So in theory, if everything was right in the world, you’d only need an impact wrench that had a working range of 100 – 160 ft-lbs. But we know it doesn’t work like that, the weather, rust, road salts, and over-tightening can cause the lug nuts to be on solid.
The best and easiest way to break them loose is the hammering action of an impact wrench, something with enough torque to bust them loose.
But why does an impact wrench work so well? In a nutshell, the combination of torque, hammer action, speed, and the final ingredient – Making it all happen at once, that’s what creates the right conditions to bust loose frozen lug nuts.
So what’s torque?
It’s a measure of how much turning power the wrench has, tightening and loosening torques will be different. The Dewalt has a max torque of 700 ft-lbs and a breakaway torque of 1200 ft-lbs. Impressive!
What’s hammer action?
A lug nut will often hang on tight because the friction between the threads is so great. Hammering on the lug nut while also turning, reduces the friction and that’s why impact wrenches work so well. Hammering action is measured in IPM (Impacts Per Minute). Dewalt wrench runs about 2400 IPM.
Revolutions Per Minute, it’s the speed of the driver, how quickly it turns the sockets. The Dewalt has 3-speed settings and a progressive trigger, meaning power is fully controllable. Position one 0 – 400 rpm, position two 0 – 1200rpm, and position three 0 – 1900 rpm.
You can buy an impact wrench that runs about 300 ft-lbs, and that might work OK in a controlled environment, but when you really need the power, 300 ft-lbs won’t do it.
You’ll need a wrench with at least 500 ft-lbs, the Dewalt weighs in at 700 ft-lbs of torque.
The Dewalt is fitted with a durable, efficient, and powerful brushless motor, it’s the latest technology in cordless motors. The brush-less is a prised motor and will only be fitted to the very best kit.
The wrench runs on lithium batteries, I already know they’re good because I have two. I’m always surprised by how long they hold a charge, it’s counted in months. That’s important because a flat impact wrench in the trunk is pretty much useless in a crisis.
The feature you’ll likely find the most convenient is the delayed LED lights. Hit the trigger and the lights stay on for almost half a minute, great for hunting that one fugitive that won’t cooperate.
All in all, this is an impressive tool, capable and durable, it’s an investment.
Features I Look For In An Impact Wrench
The wrench doesn’t need to be more wrench than you need, no point in having a wrench that can handle 1800 ft-lbs if you’ll likely never need half of it. Having too much wrench is going to be a waste of money, cumbersome to store, and difficult to use. Try and match the tool to the application.
I won’t consider buying a cordless impact wrench if it doesn’t have these features:
- Brush-less motor
- Min 500 ft lbs torque
- Adjustable torque
- ½ Inch drive
- Known brand name
- Parts available
- Long warranty
An impact gun has the ability to cause a lot of damage, if the gun is set too high, it will strip threads, easy to do and not so easy to repair.
Maintenance And Getting The Best From Your Wrench
Maintenance is minimal, they’re greased for life, so there’s nothing to do there. The best way to care for your new impact is to keep it dry, store it in a waterproof bag, safely secured it in the trunk, don’t want it sliding around.
Charge the battery once a month keeps them vibrant. Allow the battery to run all the way down from time to time, and before charging allow the battery heat to room temperature. Allow the battery to fully charge overnight.
If the battery is above 105°F or below -40°F, it won’t charge. If you live in a really cold climate, like minus stupid, wrap the batteries in an insulated blanket while in storage.
What About Cheaper Models
So what’s the main difference between the Dewalt impact and other less expensive impact tools. Well, you know the saying, you get what you pay for, mostly it’s true.
A cheaper tool is usually cheaper for a reason, and that’s OK. The trick is to match the tool to the job it’s going to do.
No point in having more tools than you need, but equally, there’s no point in having a tool that just isn’t up to the job. Using the wrong tool leads to frustration, sometimes followed by injury.
All quality impacts will have a brush-less motor, anything other than a brush-less is less, power efficiency, and durability. So whatever wrench you buy, check out the Torque value, IPM, and RPM.
Better quality metals are used in crucial components like the heavy-duty impact hammer.
A quality tool will have a long warranty, not the legal minimum.
More time and money will have been spent developing the ergonomics of the tool. The result is experienced as a tool that feels comfortable and intuitive to use, probably not so important to the occasional user.
Impact wrenches need impact sockets, while a regular socket will fit on the wrench, it’s not advisable to use them.
I do have a good set of impact sockets, I just need to listen to my own advice and actually use them. For the Impact sockets, I’d buy Gearwrench 39 piece, pick metric, or SAE.
Can you use a drill to take off Lug Nuts? No, a drill is not designed to loosen fasteners. An impact wrench with a minimum of 500 ft-lbs torque is required to remove lug nuts.
What tool do you use to remove lug nuts? An impact wrench works best, either battery-powered or air-operated. A tire Iron is more commonly used and is generally stored in the trunk of a car. In Europe, a tire Iron is known as a Wheel Brace.
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John Cunningham is an Automotive Technician and writer on Rustyautos.com. He’s been a mechanic for over twenty-five years and has worked for GM, Volvo, Volkswagen, Land Rover, and Jaguar dealerships.
John uses his know-how and experience to write fluff-free articles that help fellow gearheads with all aspects of vehicle ownership, including maintenance, repair, and troubleshooting.