In our test of car waxes, we found that pricier ones favored by enthusiasts do not necessarily work better than some less-expensive brands. The two top performers cost just $7, while a product selling for $32 ranked no better than the middle of the pack.

We also found that any wax good enough to provide some protection still requires a dose of good old-fashioned hard work. Easy-to-use spray-on, wipe-off products may save time and work, but they fared worst in our durability tests and were least effective at cleaning. Liquid and paste waxes did better as a group, but they required more effort to apply and remove.

With the advent of the clear coat, the transparent protective top layer of paint that has been used on new cars for the past few decades, you aren’t likely to improve the shine on any new vehicle. But over time, sunlight, acid rain, road debris, and other environmental factors take their toll on a vehicle’s finish. Regular washing is the most important aspect of paint care, but the added protection of wax can also help.

Many newer waxes and polishes are made of synthetic ingredients, but some are still formulated with natural waxes such as Carnauba, as they have been for ­generations. The synthetic waxes in this test, however, are most likely quite different from the ones in our May 2000 test. Since then, manufacturers have reformulated their products, reducing levels of volatile organic compounds to meet California Air Resources Board regulations.

When we tested 28 products, including 16 liquid waxes, 5 pastes, and 7 of the spray-on, wipe-off variety, we found that liquid waxes provide the best cleaning and protection. But contrary to conventional wisdom, in our tests they required more effort than paste waxes to apply and remove. As a group, liquids were the hardest to apply evenly, and they took the most work to buff out. In addition, some left a powdery residue that had to be wiped off. Even the top-rated Black Magic Wet Shine Liquid Wax required an extra bit of buffing to eliminate any streaking. And our other best all-around choice, Turtle Wax Carnauba Car Wax T-6, can cause slight scratching or hazing on newer dark-colored finishes.

Paste waxes were once the most common type of wax; now they are the least. They also were once the hardest to apply, but new formulations are easier to spread. Pastes often come with a reusable applicator to spread the wax, a convenience that makes it easier to apply the wax neatly and keep it off glass or plastic surfaces. But some of those applicators must be moistened before use.

Spray-on, wipe-off products are the newest development in car wax. Convenience and time savings are their strong suits. Some can even be applied to a car still wet from washing. But convenience comes at a cost, since this group fared worst in our durability tests.

All waxes require elbow grease, patience, and time. Depending on how fast you work, how thorough you are, the size of your vehicle, and the product you choose, expect to spend at least an hour to do a decent job. Match the car wax to your car-care needs to see which type of product best suits your needs.

Consider the age of your car. If It’s one or two years old or still has a good finish, an easy spray wax might be all you need. But keep in mind that these products wear out the fastest. No wax will improve the shine on a newer car. But if you don’t plan to replace your car for a while, waxing will help preserve the finish over time.

If you have an older car, or one whose finish has already begun to oxidize or has embedded grime, you may want to consider a product that scored high for cleaning to help bring back and maintain the finish. Liquid waxes proved the best in cleaning.

Watch out for abrasion. Waxes can be abrasive, some more than others, and the tiny particles in car waxes or harsh chemicals can leave fine scratches or a haze on your car’s finish.

Dark-colored vehicles show scratches more easily than lighter-colored ones. If you own a black or dark-colored vehicle, be especially wary of products that scored low in our scratching and hazing tests.

The same abrasiveness can make clear-coated surfaces look hazy or cloudy when the finish is marred by fine scratches, giving the paint a duller look than before waxing. Most wax packaging indicates whether a product is safe for clear-coat finishes.

Consider how much plastic is on your car. Some waxes can leave a visible residue on nonglossy, porous plastic parts such as bumpers, plastic body panels, and door trim. Those parts are often black or gray, and some newer cars may have a lot of them. If that sounds like your car, choose a product that scored well in our compatibility-with-plastic tests. Once wax gets on those surfaces, it may be necessary to use a commercially available plastic cleaner to get rid of it.

If saving time and effort is your priority and your car’s paint is in excellent condition, a spray-on, wipe-off product may be your best bet. Spray-on waxes can also be used for a quick touch-up between conventional waxings. These waxes don’t clean as well as or last as long as liquids or pastes, but that’s not an issue if you wax often. And the more often you wax, the more you’ll appreciate their ease of application.

With any wax you choose, we recommend you first try using it on an inconspicuous area such as a doorjamb. And regardless of how hard you work, how much you spend, or what longevity claims manufacturers make, don’t expect any wax to last all that long. All of the products we tested showed a significant loss of protection within about five weeks.