Series II supercharged V6 Regal LS and GS performance The Regal LS from the factory had a 1/4 mile (≈400 m) elapsed time (ET) of 15.8 seconds and could do 0-60 mph in under 8 seconds. The supercharged Regal GS had a 1/4 mile ET of 14.9 seconds, and acceleration to took 6.7 seconds. The Regal GS, equipped with the supercharged 3.8 liter V6 engine (L67) produced & of torque. The Regal GS's PCM has programming that activates torque management to reduce wheel spin at launch. The Regal LS was EPA rated at 19/30 MPG city/freeway while the supercharged Regal GS was EPA rated at 18/27 MPG city/freeway. Regal LSX and GSX (SLP Performance) In the 2003 and 2004 model years, Buick, in collaboration with SLP Performance, came out with the Buick Regal GSX. They offered dealer-installed options and dealer-supplied accessories for both LS and GS models. Like the GS Buicks that came before it, the SLP GSX came in three power train packages, referred to as stages. The Stage 1 package added 10 horsepower with the addition of a dual stainless steel cat-back exhaust system and free-flowing cold air induction system. If you opted for the Stage 2 package, a Hypertech Power Programmer with an SLP custom calibration tune was included with the Stage 1 components — good for an extra 20 horsepower. The range-topping Stage 3 package added a 3.5-inch smaller diameter supercharger pulley to crank up the boost. With an advertised 30 more horsepower than stock, the Stage 3 GSX was conservatively rated at and of torque. Since the parts were available from SLP over the counter for many years, there have been quite a few Regal GS sedans that have been cloned into a GSX for both appearance and performance purposes. Though the model didn't officially debut until 2003, a licensed SLP dealer could perform the transformation on any Regal GS from 1997 to 2004. A true GSX can be verified from an SLP door jamb label with the correct part number for the kit. Joseph Abboud Edition From 2001 to 2004 Buick offered a Joseph Abboud appearance package on both the GS and LS models. This package included either a solid taupe or two-tone taupe/chestnut leather seats, two-tone leather-wrapped steering wheel, leather shifter handle and boot, 16" aluminum wheels; and Joseph Abboud signature emblems on the front doors, floor mats, front-seat headrests, and taillights. China