The first Cherokee to be certified and go on the market was the PA-28-160, in mid 1961. The PA-28-150, identical except for the lower-compression engine, arrived a few months later. The -150 and -160 were built side-by-side until both were discontinued in 1967, leaving the Cherokee 140 trainer (also 150 hp, despite the name), the Cherokee D 180, the -235B, and the new 180 hp Arrow.
The -160 had a max gross weight of 50 pounds more than the -150, all but five pounds of that went to improved useful load. It was a skosh faster and climbed better than the -150, and only cost $510 more -- less than a 5% difference. So why two so similar models on the production line at the same time?
Those were the days when there were three grades of avgas -- 80/87 octane, 91/96 and 100/115. The Cherokee 150 could use the less expensive -- and still plentiful -- 80/87, while the -160 required at least the 91/96 grade. If your airport was one of those that didn't happen to have a 91/96 pump, you had to use the even costlier 100 octane. This made direct operating costs of the -160 significantly more than the -150.
So for a lot of new airplane buyers in the 1960s, the step-up in performance in the PA-28-160 wasn’t worth the added operating cost over the -150. Higher-compression 160 hp engines made a comeback in the mid 1970s on the Warrior II and C-172N, when 80 octane fuel was no longer available, and there was no longer an economic advantage to lower-compression engines (other than ability to use mogas).
A little historical perspective on the Cherokee 140 ... In the early 1960s, Piper’s only two-seat trainers, the tube-and-fabric Super Cub and Colt, didn’t offer much competition to Cessna’s modern, all-metal 150. Piper was developing a new trainer, the attractive low-wing, two-seat PA-29 Papoose, which featured a new-technology, plastic-composite construction. Before certification, however, it became painfully apparent that the plastic airframe was not ready for prime-time — or even direct sunlight — and the project was abandoned.
So to supply their dealers with a ”modern” trainer as quickly as possible, Piper took the full four-seat Cherokee 150, moved the aft cabin bulkhead forward, removed the rear seats, baggage compartment and baggage door, redlined rpm down and repitched the prop to produce only 140 hp, and called it the “Cherokee 140”, introduced early in 1964. The -140 was intended for fleet sales to flight schools, unlike the Cherokee 150, which was a family airplane for private buyers. The -140’s gross weight was also initially limited to 1950 lb, so that, like the C-150, it could be operated in the utility category at full gross weight. The 140 hp limitation made it more palatable to flight school bean counters, in comparison to the Cessna’s frugal 100 hp. Piper also quoted performance at an “instructional cruise” power setting of 50%. Cherokee 140 base price was $8500, only $1000 more than the smaller, lighter ‘64 Cessna 150D.
A year later, Piper re-thought the Cherokee 140’s role. Power was re-upped to 150 hp (2700 rpm), and gross weight increased to 2150 lb (equal to the Cherokee 150). Temporary snap-in rear-seats became an option (“2+2 Cruiser”), but those filled what had been the two-seat -140’s baggage area. Beginning with the 1969 Cherokee 140B, the options list included a molded plastic rear cabin bulkhead, which formed a tiny baggage area and hat shelf behind the snap-in seats, but there was still no exterior baggage door. The -140’s snap-in rear seats offered even less legroom than did the permanent rear bench seat of the Cherokee 150/160, which itself was not spacious.
The Cherokee 150 and 160 were discontinued in 1967, while the Cherokee 140 soldiered on, with the original short PA-28 fuselage and Hershey-bar wings, through 1977, when a new trainer, the PA-38 Tomahawk, was ready for market.
From 1971 through 1974, Piper offered a fleet-spec version of the -140, called “Flite Liner”, to its Piper Flite Center network. Returning to the original concept of the Cherokee 140, the Flite Liner was a two-seater with the old rear cabin bulkhead, a standardized, utilitarian equipment package including gyro panel and a basic navcom radio, and no factory options other than blue trim paint instead of red. Many Flite Liners have since been modified to install the snap-in rear seats. If you see a Cherokee 140 with a registration number ending in “FL”, chances are it was built as a Flite Liner. In the late 1980s, Piper did much the same thing with a stripped-down, fleet-spec trainer version of the Warrior II, called “Cadet”.