1982 - Renault increases its holdings to 20 percent. Signal reduces its holdings in Mack by 10 percent. Mack introduces the MH Ultra-Liner model, featuring the industry's first successful all-fiberglass, metal cage-reinforced cab. The new design resulted in industry-leading advancements in cab-weight reduction and corrosion resistance. 1983 - When Mack Trucks, Inc. again became a public corporation in 1983 with a public offering of 15.7 million shares of Mack Trucks, Inc. common stock, closer ties had been established with Renault. These ties originated when the two organizations negotiated in 1977 regarding the distribution of a medium-duty diesel truck series in North America and parts of Central America and the Caribbean. Renault and Mack forged a working partnership with the successful introduction of the Mack Mid-Liner series in 1979, studying many of the key issues facing both companies on a global basis. Renault increases holdings to 40 percent. Signal holdings reduced to 10.3 percent. 1987 - The commercial vehicle division of Renault -- Renault V.I. -- undergoes a financial reorganization, and buys out the Mack shares from its parent company. Mack introduced the E7 series of 12-liter engines in 1988. The line included 16 different engines with horsepower ratings ranging from 250 to 454. The E7 boasts the industry's best horsepower-to-weight ratios for customers concerned with achieving maximum productivity. 1988 - Mack introduces the CH series for highway applications.