Since New York doesn't have a residential parking permit system, can a tourist park in Manhattan for free?

While the other answers correctly mention that the Alternate Side Parking rules are difficult and arcane, there is no longer the need to actually understand them as a tourist. Instead, you can use one of the online ASP maps to find streets which you can use for free parking at any given moment. For example SpotAngels has the following handy map:

It shows free street parking, paid street parking and parking garages, all in the same view. Most of the free spots will probably be busy by the time you arrive, but it might be worth a shot.

Another helpful tip, is look for spots in neighborhoods near your destination where street parking is usually more available, then you can hop on a nearby subway line to get to your destination. For example, if you want to go somewhere off the 2/3 or A/C or 4/5 or J/Z line, there is usually free parking between the South Street Seaport and the Brooklyn Bridge – and these spots are a short walk from all these subway lines at the Fulton Street Center (Fulton St. & Broadway). As stated above, just make sure you are not violating the alternate side parking rules on nearby signs, and that you are not blocking fire hydrants or driveways.

A couple other examples: on Riverside Drive from about 72nd Street on the Upper West Side all the way up to Washington Heights – this is a short walk to many 1 and 2/3 train stations. Bonus: there are hardly any driveways.

I would like to point out that NYC, Washington D.C. and other “large” meto areas in the New England area are generally considered “public transit friendly.”

For example, last time I stayed in D.C. I parked my car at the hotel upon arival, and took combinations of the Subway, Train, Taxi, and Bus anywhere I wanted to go. I didn’t drive at all that week.

IIRC NYC and srounding areas are very similar. You typically walk, or take public transit everywhere.

Your hotel should offer you some parking options, though, if your flying in, best to not even get a rental. Just take a taxi instead.

Yes. Any tourist can park in the same areas as a resident. The only “benefit” for residents of NYC is an exemption from paying the NYC 8% parking tax, though they still pay NY State portion of the tax of 10.375%.

In many areas of the city, largely south of E52nd street, almost all street parking is prohibited with exceptions made for Commercial vehicles (NY state license plate reads “commercial”) and Handicap/Disabled parking.

Many parking garages offer coupons by visiting their site first, then downloading to your phone or printing. Icon Parking, Quik Park and LAZ Parking seem to own most garages. Sites like ParkWhiz can locate cheap parking for you, and often offer deals by directing traffic to specific garages.

All parking garages by law must post the rate clearly. It won’t include the 18% sales tax. Be sure to know your car size, as they will charge extra for long, wide, tall, oversize, lifted, big tires, SUVs, etc.
Also, the rates are largely by-the-hour. Rates are lowest for people who arrive early (usually 7am – 10am) and stay over 8 hours and less than 12 hours. In that case, it will usually be a flat fee. I pay $27.00 (includes tax) to park in Midtown (busy area) from 7:00am – 6:45pm.

Some helpful notes, if you’re serious about street parking:

• Look closely where a fire hydrant is located. You may not park within 15 feet of either side. You will be ticketed. The distance will not be marked.
• You may not park at the end of any street with either end of your car protruding into a crosswalk, unless the crosswalk is specifically not painted in the parking area as to allow room for a car. This is rare.
• Do not park too far away from the curb. You will get a ticket. Usually a 8″ to 1ft max. Do not park with your tires on and touching the curb, you will be ticketed.
• It is possible to get a parking spot on the street. These can be found by waiting on a street until the street sweeper passes. As soon as they pass, drive into a spot behind the street sweeper and park. Do not leave your car, as you will still get a ticket. You must wait until the parking restriction time has elapsed, even though the street sweeper has already come. There can be fights that erupt, as residents wait in their cars idling on one side of the street and rush to the other side.
• NYC DOT (Dept of Transportation) map with parking restrictions. Includes Alternative Side Parking (ASP) rules. Click “Parking Signs” as a map layer.
• ASP schedule is tweeted daily at 7:30am and 4:30pm ET by Twitter account “NYCASP”.
• The ASP calendar for 2016, 2017 and temporary suspensions.
• Manhattan residents are exempt from paying the additional New York City 8% Parking Tax. Manhattan residents instead pay only the tax on parking services at a rate of 10.375% instead of 18.375% that is imposed under State law.

In Theory… sure.

In practice…

Unless you have a fairly good understanding of New York’s somewhat arcane Alternate Side Parking rules, the patience of a saint, and the willingness to walk all the way across town once you’ve found a spot – and then to move your car daily and do it all again because of the aforementioned ASP rules – you’re not going to find this viable or pleasant.