The four-seat, four-cylinder, tricycle fixed-gear singles are in large part the basis for general aviation flying. There are a lot of them out there. They fly a big percentage of the general aviation hours, and one of them is often a first airplane with many pilots satisfied with them as the only airplane they will ever own. (And, yes, pre-1968 Cessna 172/Skyhawks had six-cylinder engines, but the horsepower was 145, close to many of the four-cylinder engines.)
There is a misconception that these airplanes are for first-time owners and relatively new pilots only. They are great for that, but they are also great for an experienced pilot who wants to have an airplane and fly it without busting the budget.
Because these airplanes were built over a long period of time, a lot of them were built, and there were many different versions of the same model, so there's a great selection in the used airplane market.
Before going into the characteristics of the airplanes let's look at the dollars which are, when compared to more esoteric airplanes, one of their primary attributes.
The best way to think about the cost of airplane ownership is for the first hour every year, which is whatever the fixed costs total. Hangar, insurance, an annual inspection, and an allowance for maintenance surprises must be charged to the first hour flown each year because you must spend that money for one hour or hundreds. I estimate that the first hour in one of these airplanes is about $8,500, plus or minus, depending on a lot of factors, including where the airplane is based and whether or not it is hangared. It's up to the individual to quantify this; the number offered here is just a starting point.
After you pay for the first hour with its fixed costs, each hour thereafter costs the price of fuel, and an hourly reserve for engine overhaul plus oil changes and other routine maintenance that is driven by the number of hours flown. These airplanes offer good low-cost flying after the unavoidable and infamous first hour. If you fly 100 hours a year or less, though, the total annual out-of-pocket dollars would probably be more than it would cost to rent an airplane for those hours. The difference between renting and owning airplanes is, however, like the difference between petting the neighbor's dog and having your own to curl up on the foot of your bed on those cold nights.
There's little or no depreciation in these used airplanes, but any pilot would be kidding himself to not put some bucks in the budget for new gizmos. The airplanes and engines change little over the years, but the avionics and other accessories that we want are becoming more exciting every day.