Consumer Reports found that good windshield wipers aren’t pricey, but drivers might have to replace them every six months or so. COURTESY PHOTO

Consumers need not spend a lot of money to get good windshield-wiper performance, according to the editors of Consumer Reports, but they might need to replace them every six months or so.

CR tested 15 wipers and found that three of the top four were among the least expensive: the top-rated Valeo 600 Series ($9, 18-inch; $15, 24-inch); the Anco 31 Series ($7, 18-inch; $10 24-inch); and the Michelin Rainforce ($7, 18-inch; $7, 24-inch).

CR also found that all of the tested wipers provided “very good” or “excellent” performance when new, but most quickly degrade after six to nine months of regular use. The RainX Latitude ($17, 18-inch; $21, 24-inch) was the only wiper that began with very good performance and maintained that level through six months. All others dropped in performance after six months.

Depending on the model, that deterioration showed up on the windshield as streaking (leaving lines of water behind), smearing of the water (instead of clearing it) or missed areas of wiping.

CR tested the wipers on 185 staffers’ cars. About half came with wipers that needed replacing, showing that drivers often don’t notice the slow degradation and leave wipers on longer than they should.

The tested wipers included six beam-blade models, a relatively new design. Unlike conventional wipers, beam blades have no external frames. As a result, they are promoted as providing more uniform pressure on today’s curved windshields and therefore better wiping performance.

Beam blades usually cost more than conventional wipers, but CR’s experts didn’t see a notable advantage in regular use. The beam-blade model that rated highest was the RainX Latitude.

CR also evaluated the wipers on ease of installation and removal. All of the cars in their test had a common hook-type mount, in which the old wiper is simply pulled off the metal wiper arm and the new one is snapped into place. In CR’s tests, only the Michelin Optimum, Trico Exact Fit and Trico Teflon Blade proved somewhat difficult to remove, sometimes requiring tools.

The bottom line is that all recommended models deliver good performance. But CR advises replacing wipers every six to 12 months. Check the owner’s manual for the correct size and installation method.

CHOOSING AN AUTO BATTERY: CR’s latest tests show that a couple of the least-expensive models of auto batteries perform virtually as well as batteries that cost more than twice as much. CR was particularly impressed with Wal-Mart’s EverStart models, priced at $75. They were tested in five group sizes, and all but those in size 34/78 scored near the top or middle of their group and are CR Best Buys.

Visit the Consumer Reports Web site at