Skip Lisell, owner of Lisell Auto Service in Fridley, has been selling wiper blades "like crazy" lately, he said. "People are having problems this winter like we haven't seen for several years."

In snow and freezing rain, wiper blades in poor condition become apparent quickly. If the rubber is rigid or chipped, it's time for new wipers. Streaking, smearing and chattering (noisy blades) are also an indication to replace.

More important, those are signs that visibility is compromised, causing a safety concern. Car owners used to go years without replacing wiper blades (and many still do, Lisell said), but Consumer Reports recommends every six to nine months.

Lisell doesn't believe that wiper blades need to be changed that often, but after a year, most wipers are wearing out. The summer sun, fall debris, freezing rain and heavy snow take a toll, he said.

Cheapskates might balk at paying $20 to $40 a year for replacement, but not if they've ever driven on a busy, wet road with poor wipers that clean only part of the windshield. Combine that with an empty reservoir of washer fluid and suddenly preventive maintenance is a tiny price to pay to avoid a serious accident.

Wiper replacements are one of the cheapest investments you can make for safe winter driving, said Ross Johnson of R&R Auto Repair in Minneapolis. Even though there are silicone models with a lifetime warranty, wipers that vibrate to dislodge debris and heated blades, the expensive versions don't last any longer or work better than the cheapies, according to Consumer Reports' findings.

Martha Buns, Star Tribune

The magazine found that most standard wipers, priced from $7 to $24 each, performed well for six to nine months. In a test of 13 blades, the magazine liked the Valeo 600 series for $11 to $15 (sold at Sam's Club under the Smart Blade name), the Rain-X Latitude for $17 to $21 (sold at Auto Zone, Wal-Mart, Target), the Anco 31 Series for $7 to $10 (sold in auto parts stores and auto repair shops) and the Michelin RainForce ($12).

Only the Rain-X model maintained its "very good" performance for the full six months, according to Consumer Reports. Readers at Popular Mechanics also rated Rain-X wipers as a favorite.

If you're buying wiper replacements yourself, call a dealer to determine the proper size. Most vehicles now use a longer size on the driver's side than the passenger's side. Also try Rain-X's online blade finder (www.startribune.com/a81) to determine sizes for your vehicle.

If only one blade is bad, replace both of them anyway.

"If one is worn out, its mate will surely die soon," Consumer Reports says.

John Ewoldt • 612-673-7633 or jewoldt@startribune.com. If you spot a deal, share it at www.startribune.com/dealspotter.