The DeVille, d�Elegance and Concours sedans again comprised the series.
The DeVille and d’Elegance used the 275-horsepower version of the Northstar 4.6-liter V-8 for power while the Concours featured the 300-horse Northstar.
Both versions of the engine were coupled to the 4T80-E electronically controlled four-speed automatic transmission with viscous converter clutch.
The StabiliTrak stability control system was already standard equipment on the Concours and offered on the DeVille and d�Elegance as part of a safety/security option package that also included an electronic compass/mirror, audible theft deterrent system and programmable garage door opener.
The DeVille series offered four new exterior colors for 1998:
Inside, two new interior color choices were available:
Camel (available only in leather)
Pewter (available in cloth or leather in the DeVille and leather only in d�Elegance and Concours)
Additionally, the series’ personalization feature added two new locking modes to the three that already existed:
all doors lock when shifting out of park and only the driver’s door unlocks when the key is turned off.
all doors lock when shifting out of park and unlock when the key is turned off
Also, the remote keyless entry fob added a feature: when the lock button was pressed, the horn sounded to verify that the doors were locked.
All three sedans now came with an airbag warning label affixed to the passenger visor and each received a revised electrochromic day/night inside rearview mirror.
The radio installed in DeVille series sedans also received a mute button and Theftlock, while radio data system (PDS) and weather band were offered as part of the optional Active Audio sound system.
PDS allowed broad-casters to deliver a 1200-bits-per-second data stream along with audio content.
The Concours’ standard radio also received an in-dash, single-slot CD player.
Unique new standard features to the Concours included restyled 16-inch cast aluminum wheels as well as the next generation of Magnasteer that reacted to lateral acceleration as well as speed.
When the cornering rate was up, as sensed by an on-board lateral accelerometer, steering effort was automatically increased to enhance the driver’s feel of the road.
Both the d�Elegance and Concours added heated front seats to their list of standard fare.
The OnStar in-vehicle communications system was again offered to DeVille/ d�Elegance /Concours buyers as a dealer-installed option.