The Imperial moniker has a long and storied place in Chrysler history; an Imperial was the tip top of the line; the very best. There hadn't been an Imperial produced since 1983. Ironically, the 1990 Imperial was introduced during diffcult financial times for Chrysler; just as the 1981 model was. Unlike that Imperial, this one was a four door sedan, based off the K platform that was just beginning back in 1981. Also unlike that car, this one wasn't as far removed from its brethren (the 1981-1983 Imperial was based on the Cordoba chassis). As much as Chrysler tried, it was just too obvious that the EEK Imperial was near a twin to the Fifth Avenue. Aside from length (203" compared to 198.6" - due to the front clip) specifications for the Imperial are near the same as the Fifth Avenue. For 1991, Chrysler introduced their 3.8 V6 motor, which was standard on the Imperial (optional on Fifth Ave). The 3.3V6 was the only motor available in 1990. The differences between the cars were in the details. The Imperial was unaffected by the facelift afforded the Fifth Avenue and New Yorker in 1992.
Detail Differences
The Interior
A slightly different dashboard top, unique seat coverings and door panels pretty much sum up the differences that set the Imperial apart. Items that were options on the Fifth Avenue were standard on the Imperial, and by choosing the Imperial buyers achieved the appearance difference that set it apart from other New Yorkers more than the Fifth did.
The Exterior
An extended Landau roof, lengthened and taller front clip, and unique taillight treatment were the prime distinguishing marks of the Imperials exterior.
The Warranty
To emphasize the higher level of luxury of the Imperial and Fifth Avenue, those models were covered under Chrysler's Crystal Key Owners Program, which provided 5/50 bumper to bumper, 7/70 engine and powertrain, and 7/100 outer body rust through protection.
The protection afforded lesser models was a 1/12 bumper to bumper and 7/70 engine/powertrain along with the 7/100 corrosion coverage.
Note that this coverage is only mentioned in the 1990 and 1991 brochures, the 1992 brochure just says 'see your dealer for details' without mentioning Crystal Key at all. The 1993 brochure only offers the choice of 3/36 bumper to bumper OR 1/12 bumper to bumper along with 7/70 engine powertrain. 7/100 corrosion came on all cars. This seemed to emphasize the phasing out of the luxury K based sedans.