Here is the translation of the provided text into English:

The largest model in the Mezzo series introduced at the beginning of 1991 was the four-cylinder 6600 (105 hp). Its differences from the smaller models included a standard powershift transmission, larger tires, a more robust rear axle, and a higher lifting capacity. The lift arms were equipped with quick hitch levers. The parallel model 6600E featured Autocontrol III, which included traction control, an onboard computer, and powershift automation. As an optional extra for the 6600, a stronger industrial front axle was available.

In spring 1993, a three-step powershift called Delta Powershift was introduced. The two highest gears of the powershift matched roughly the previous gears, and there was now a third, slower gear below them. As before, operating the powershift gave a noticeable jolt. In spring 1994, the further developed Autocontrol II and IV were introduced. The 6600 was the smallest model available with an optional 50 km/h top speed.

In autumn 1996, the "Juha Kankkunen signature model" 6800 was launched. With its 115 hp, it was the most powerful four-cylinder on the market. Its difference from the 6600 was a wastegate turbocharger and an intercooler.

At the beginning of 1997, the model 8000 was replaced on the domestic market by the 6900, which was technically almost identical. The engine was equipped with a distributor pump and had 2 hp more power. The "dairy farm six" 6900 was technically mainly based on the model 6400; for example, its lifting capacity was lower than in the most powerful four-cylinders. Initially, a special edition Finlandia was available for the 6900, which featured blue and white coloring and, in a specially priced equipment package, included e.g. a turbine clutch, air-sprung seat, and a newly introduced button clutch.

In summer 2001, the 6800, which alongside the Hitech models was the only large Mezzo model still in production, received a distributor pump, 5 hp more power, and a 7-ton lifting capacity.

This is an automated translation. Please report any issues in the translation.