Very, very efficient. I was able to get my 4WD truck where some 4WDs with bare all-season tires couldn't. The wheels were undamaged but rusted after three days of use. It looks like it's just surface rust, but it's unknown how many more seasons they will last. Please read below if you have no experience with chain or cable hoists. This can save you a lot of trouble. The Glacier/Pewag website has a very helpful size chart for passenger items. Be sure to check all applicable laws regarding when and where you can use chains on public roads! Also, don't forget to buy tensioners. They align the chain, which reduces the likelihood of failure and subsequent damage to the vehicle. Update: It's been almost two years since I bought them. That's how they survived. I've used them probably 10 times and driven about 250 miles on them. Even though they were very rusty in the garage over the summer, they still work great. Rust dissolves immediately after snow melt and friction. Rust does not seem to penetrate deep into the steel cables and does not adversely affect their strength. When it's cold enough and the streets aren't full of salty, soggy goo, they don't rust. If you rinse them after every wet use and hang them to dry and don't use them for a long time in such condition, they can last a long time. WD-40 isn't a bad idea to protect them during storage. Also, DO NOT spin tires, drive faster than 50 km/h or use them at all if there is not enough snow/ice to completely isolate them from the road surface. A little wheel slip and CREEP on dry pavement with fuses on for a few hundred yards to stop and remove them is fine, but a lot of wheel slip or time on dry pavement can snap your tires or worse, snap wires and burn snot out the body of your car. They work best when you're not spinning the tires, and it's unwise to go over 30 mph in chain-requiring conditions anyway. Broken brake lines and hoses are also a possibility in a broken cable scenario, so keep that in mind. Observe manufacturer information T! Stop frequently and check during use. If you are not careful, extensive property damage or serious injury can result. I only use them when I can't avoid the road and that's the only option. Anyway, I mostly use them on private gravel roads. Winter tires are better, but Virginia doesn't have enough snow to justify the investment.