as the diesel engine offering. For 2018, an "EcoTec3" 4.3L V6 was introduced as the base gasoline engine (sharing little more than its displacement with the Vortec 4300); the same year, CNG/LPG capability was added as an option to the 6.0L V8. For 2021, the 6.0L V8 was replaced by an all-new 6.6L V8 (L8T). The 1500 series either has a 3.42 or 3.73 axle. The 2500 and 3500 series van will have a 3.73 axle or 4.10 axle. Body design Far more aerodynamic than its predecessor, the Chevrolet Express derived much of exterior styling from the Chevrolet Astro mid-size van (including its flush-mounted exterior glass), deriving its grille from multiple trims of the Chevrolet C/K pickup trucks. Similar to the APV minivans, the Express adopted high-mounted taillamps (besides the rear windows), placed above the rear door hinges. In a design advancement for the market segment, the rear doors are hinged to open nearly 180 degrees, allowing the vehicle to back up to a loading dock. The cargo van is offered as a two-passenger vehicle (initially with an optional passenger seat delete); the passenger van is offered as a 5, 8, 12, or 15-passenger vehicle (the latter, only with the extended 155-inch wheelbase). In reverse of its predecessor, 60/40 split side doors were standard, with a sliding door offered as an option (initially at no cost). From 2003 to 2008, side doors were offered on the driver side; only the split-panel doors were offered, and only on standard-wheelbase bodies. Trim For its 1996 launch, Chevrolet used the Chevrolet Express model name for full-size passenger vans, with Chevrolet Van returning for cargo vans (renamed Express Cargo Van for 1999). The Express passenger van was introduced with two trim lines: an unnamed base trim (geared largely towards fleet sales) replacing the Sportvan and the upgraded LS, replacing the Beauville. For 2001, an upgraded LT trim was introduced, but was dropped for 2003. For 2006, the trim line was revised again to the current nomenclature, with the base trim renamed LS, and LS renamed LT. In line with the previous Chevrolet Van, the Express uses "G" as its internal model designator ("H" was used for all-wheel drive vans during their production). In line with C/K pickup trucks, the Express/Savana adopted the 1500/2500/3500 payload series designations. After the 2014 model year, the -ton 1500-series was discontinued (with GM citing it as the lowest-selling version).