When driving in snowy or icy conditions, snow chains provide extra traction and control for your tires. This helps your vehicle maintain grip on slick roads. Snow chains either go on two or four tires. So how do you decide whether you need 2 or 4 snow chains?
What are snow chains?
Snow chains are metal chains that attach to your tires. They consist of circular metal rings that are connected by cross chains. The rings wrap around the circumference of your tires while the cross chains grip the road.
When your tires start to lose traction in snow or ice, the metal chains dig into the slippery surface. This gives your tires something to grab onto for continuing spinning and moving forward. Snow chains provide grip, braking control, and steering ability when driving in wintry conditions.
What vehicles use 2 snow chains vs. 4 snow chains?
Rear-wheel drive vehicles and all-wheel drive vehicles require 4 snow chains. That’s because these types of drivetrains send power to both axles. If you only put snow chains on the front or rear tires, those chained wheels may spin while the opposite axle loses traction.
Installing 2 snow chains on rear-wheel drive or AWD cars can actually reduce control in snow. The chained tires will want to propel the vehicle forward while the unchained tires slide around. This is an unstable driving situation.
For optimum traction and safety, rear-wheel drive and AWD vehicles need 4 matching snow chains. The snow chains help all four wheels maintain equal grip through snow.
Front-wheel drive vehicles only require 2 snow chains on the front tires. Since the front wheels propel front-wheel drive cars, chaining up the rear wheels doesn’t offer much benefit. The moving front tires need the most help gripping winter roads.
So the basic guidelines are:
- Rear-wheel drive vehicles need 4 snow chains
- All-wheel drive vehicles need 4 snow chains
- Front-wheel drive vehicles need 2 snow chains on the front
When to use 2 vs. 4 snow chains
Use 4 matching snow chains any time you’ll be driving your rear-wheel or AWD vehicle in heavy snow, ice, or slush. The roads need to be bad enough that your tires alone can’t find traction or control.
For front-wheel drive cars, put on 2 snow chains if you’ll be tackling untreated roads that are snow-covered, icy, or slushy. Chains give your front tires grip when they start slipping and spinning.
You generally don’t need any snow chains if roads have been plowed and salted. All-season or winter tires can handle these cleared conditions. Save your chains for storms that overwhelm road crews and leave roads messy.
Benefits of 4 vs. 2 snow chains
The main benefits of using 4 snow chains instead of just 2 are:
- Traction and control – All 4 wheels gain extra grip and braking ability on ice and snow.
- Stability – The vehicle won’t fishtail or slide sideways as easily with 4 chained tires.
- Symmetry – The same traction performance at all corners creates balanced handling.
- Peace of mind – You don’t have to worry about spinning chained tires and opposite uncontrolled tires.
The downside is that 4 snow chains cost about twice as much as 2 chains. You also have to spend more time installing 4 chains instead of just 2.
Putting 2 chains on the front tires of front-wheel drive cars provides excellent winter performance. The steering tires gain traction without creating instability between the axles. Unless you drive in extreme mountain conditions routinely, 2 front chains usually suffice for front-wheel drive.
Do you legally need 4 snow chains?
Most U.S. states don’t legally require snow chains at all. But some snow belt states mandate snow chains on certain vehicles during winter storm weather. For example:
- California requires chains on all vehicles except AWD/4WD when signs are posted.
- Colorado requires all vehicles carry traction devices like chains during winter.
- Washington requires chains on rear-wheel drive vehicles without all-season tires when traveling certain mountain passes.
When states enact chain laws, rear-wheel drive vehicles must use 4 snow chains to comply. AWD and 4WD vehicles only need chains on 2 wheels. And front-wheel drive vehicles also just need front chains.
Make sure to check chain laws for wherever you’re driving during snow season. Carry the legally required number of chains and only install them when signs indicate to put them on.
Using cable chains vs. standard link chains
Cable chains are made of metal cables that criss-cross over your tire tread. Link chains have the traditional circular rings and cross chains.
Cable chains are easier to install than link chains. They conform to your tires smoothly and provide plenty of winter traction. Their lighter weight also stresses your vehicle’s suspension less.
Link chains offer the ultimate snow/ice grip and durability. But they also rattle and ride rougher over clear pavement. Link chains cost more than cables too.
Either cable or link chains work fine for occasional use during snowstorms. Get whichever style fits your budget and driving needs.
Just make sure cable and link chains meet traction standards like SAE Class S. Poor quality or worn chains compromise winter performance and safety.
Tire Size Compatibility
Chains must be the right size for your tire’s dimensions. Measure your tire section width and sidewall height. Compare those measurements to the chain manufacturer’s sizing charts.
Chains that are too large or too small for your tires can come loose, break, and cause accidents.
Automatic vs. manual chains
Automatic chains stow along your vehicle’s undercarriage when not in use. At the push of a cabin button, the chains deploy under your spinning tires. They automatically tighten to provide traction when needed.
Automatic chains cost significantly more than standard manual chains. But they offer great convenience since you don’t have to stop and install them on the side of the road. Automatic chains engage and disengage seamlessly while driving.
Drivers who routinely face wintry driving conditions may find the investment in automatic chains worthwhile. Just know the chains will still wear out over time and need replacement like manual chains.
Infrequent chain users will probably prefer the lower cost and simplicity of manual snow chains. Take the time to practice installing them at home before your first winter storm arrives.
Driving with snow chains
Once your 2 or 4 snow chains are installed:
- Obey lowered chain speed limits, usually around 30 mph.
- Drive below the speed limit anyway for safety.
- Avoid spinning your wheels, which damages chains.
- Brake and accelerate gently to go easy on your chains.
- Avoid bumps and potholes that can break chains.
- Remove chains as soon as you reach cleared roads.
And always carry chain repair parts like quick links and tighteners. That way you can replace broken cross-chains and get loose chains tight again while on the road.
Snow chain alternatives
If you don’t want the hassle of traditional snow chains, alternatives like snow socks and traction cleats can work. These options are faster to install but don’t match the ultimate traction of snow chains.
Snow socks
Snow socks are fabric covers that slip over your tires. They provide extra grip thanks to integrated steel rings and studs on the bottom. Snow socks don’t damage roads or vehicles like chains can.
On the downside, snow socks wear out faster than chains. They can’t handle severe ice or steep terrain as well either. Expect to replace sets of snow socks each season.
Tire cleats
Traction cleats are rubber mats with metal studs that attach to your tires with elastic tension. The studs extend past your tread to increase grip. Cleats are quicker to mount than standard snow chains.
But cleats don’t provide the same level of traction and control that link or cable snow chains do. And they can still rattle and vibrate your vehicle.
Conclusion
Rear-wheel drive and AWD vehicles need 4 matching snow chains for winter driving traction and stability. Front-wheel drive cars generally only need front chains. Make sure to check your state’s chain laws before driving during winter storms.
Practice installing whichever chains you choose ahead of time. Carefully follow size guidelines and driving recommendations. Snow chains provide traction when you need it most on snowy, icy roads.
