According to our research, ConsumerReports.org provides the most credible dishwasher reviews. Editors test new models on an ongoing basis and update their ratings about once a year. At present, more than 135 dishwashers are ranked and evaluated at ConsumerReports.org for their cleaning ability, energy efficiency, noise and ease of use. Subscribers are also invited to write product reviews online, and some dishwashers receive a substantial amount of owner feedback. In addition, ConsumerReports.org offers repair data culled from a yearly survey of more than 80,000 subscribers.
Which? magazine editors offer similarly detailed testing of more than 150 dishwasher models sold in the U.K. The reviews are updated continually, and there's a bit more discussion for each model. While some dishwasher brands may be familiar to U.S. consumers, the models tested here aren't available in the United States. The editors of Choice (Australia) and Consumer (New Zealand) magazines also provide in-depth and objective reviews of dishwashers, but again, none of those tested is sold in the U.S. However, the brand reliability and general shopping information provided by all three magazines is universally helpful.
Aside from ConsumerReports.org, the only other U.S. organization we found that conducts comprehensive testing of dishwashers is the Good Housekeeping Research Institute. Its tests are thorough but cover far fewer models, and only the results for the top-rated models are provided. Moreover, the most recent report is more than a year old, and three of the four recommended models are now discontinued. There's some useful information in the annual survey of appliance owners conducted by J.D. Power and Associates; in 2011, more than 4,000 respondents evaluated dishwasher brands based on factors such as reliability, price, performance and style. However, owners aren't asked to rate specific models, so it's hard to draw conclusions from this survey.
Owner reviews at sites such as AJMadison.com, HomeDepot.com and Sears.com provide insight into reliability and durability as well as customer service.
Most reviews indicate that a higher price tag doesn't always equal performance and durability. Overall, experts say that new dishwashers don't differ much in basic cleaning ability; even less expensive models can get the job done so long as they hold up over time. Most modern dishwashers are also quite efficient, using far less energy and water than older models. According to Discovery's TreeHugger.com, replacing a dishwasher from 1994 with a new model will save $25 in energy costs and 1,000 gallons of water per year.
As of 2009, all Energy Star-rated dishwashers are required to use no more than 5.8 gallons of water per cycle, while dishwashers purchased before 1994 may use 16 gallons or more. Energy Star-rated models must also exceed federal energy-efficiency standards by at least 10 percent, which works out to about 295 kilowatt-hours per year for a standard model. (Think you'll save energy and water by washing your dishes in the sink? According to a 2004 study at the University of Bonn in Germany, even the most careful hand washers used twice as much energy and six times as much water as a modern dishwasher.)
While inexpensive dishwashers can match their pricier cousins in cleaning power and efficiency, they tend to make more noise. But user perception of a dishwasher's loudness doesn't always correspond to its stated noise output, measured in decibels; the pricey KitchenAid KUDE50CXSS (*Est. $1,220) , which supposedly produces only 40 decibels of sound, was judged "mediocre" for noise in professional tests while two LG dishwashers rated at 45 decibels were praised for their quietness by experts and owners. Even the budget-priced Maytag JetClean Plus MDB4709AWW (*Est. $420) , with a noise rating of 60 decibels, gets many comments on its quietness in user reviews. Your own noise tolerance -- along with the layout of your kitchen -- matters as much (or more) as your dishwasher's decibel rating.
Reliability is also important, and it can differ significantly among brands and in some cases by model. The various surveys in our sources generally give Bosch and Miele the highest marks for reliability, while LG and Amana come in near the bottom; however, these results differ somewhat across sources. In one survey of more than 80,000 dishwasher owners, LG models tied for last place with a reported repair rate of 21 percent; in the J.D. Power survey, however, LG was rated above average for "performance and reliability." (This score may be based more on performance and less on frequency of repair.)