Circa 1970 Piper produced a variant of the 140 marketed as the “ Flight Liner”. [...] It was a stripped down version that offered LOWER FUEL CONSUMPTION comparable to the Cessna 150. There were very little actual changes to the aircraft. The goal was achieved via revised Power Charts and a slight detent on the throttle. “ Instructional Cruise Power” was something like 60% which brought fuel usage near that of the 150.
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 in early 1964 took the existing, full four-seat Cherokee 150, moved the aft cabin bulkhead forward, removed the rear seats, baggage compartment and baggage door, moved the tachometer redline down to 2450 rpm and repitched the prop to produce only 140 hp, and called it the “Cherokee 140”. The -140 was intended for fleet sales to flight schools, unlike the Cherokee 150, which was marketed as a family airplane for private buyers, competing head-to-head against the Cessna 172. 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 150’s frugal 100 hp. For the first-year Cherokee 140, 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. In 1965 power was re-upped to 150 hp (simply by re-pitching the prop and changing the redline on the tachometer back to 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. The Cherokee 140 remained in production not only as Piper's trainer, but also as the entry-level four-seater in the Piper line, until the introduction of the PA-28-151 Warrior -- with the same engine as the Cherokee 140 -- in late 1973. The Cherokee 140 soldiered on until the end of 1977, when an all-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 GenAve navcom radio, and no factory options other than blue trim paint instead of red, and 360 com channels in the radio instead of the standard 100. Promotional material for the Flite Liner described an "Instructional Cruise" configuration of 60% power and 1800 lb operating weight.
In the late 1980s, Piper did much the same thing with a stripped-down, fleet-spec trainer version of the Warrior II, called “Cadet”.