varying both intake and exhaust for better performance. GM 4T80-E 4-speed automatic transmission Road Sensing Suspension (RSS), which monitored damping rates of the shock absorbers every 15 milliseconds, selecting between two settings. RSS was available in both standard and CV-RSS (continuously-variable) systems. 4-wheel disc brakes with Bosch antilock brakes Magnasteer speed-variable power steering, which combines conventional hydraulic power steering and magnetized "doughnuts" mounted around the output shaft, which stiffen the steering as vehicle speed increases. Later versions of the Northstar engine included the 4.6L and LH2 which began in 2004, and supercharged 4.4L LC3 created for the STS-V which are detailed below. L37 The L37 (VIN "9") was the original Northstar. It is tuned for responsiveness and power, while the later LD8 is designed for more sedate use. The L37 code had been used on all high-output transverse Northstars, even as the exact engine specifications evolved. The compression ratio for the L37 is 10.3:1 for engines built prior to 2000, and 10.0:1 afterwards. The original L37 was specified at , but 1993 production examples were rated at . The engine topped out at from 1996 through 2004 on the STS, DTS and ETC models, making these some of the most powerful domestic front wheel drive cars ever built. For 2005 the high output Northstar became Northstar NHP, and was downrated to under the new SAE certified horsepower rating system. In 2006, the updated DTS "Performance Package" model got a slight bump to . Vehicles using the L37 include: LD8 The LD8 (VIN "Y") is a transverse V8 for front-wheel drive cars. Introduced in 1994, it is designed to provide more torque than the high-revving L37. The LD8 code had been used on all torque-tuned transverse Northstars, even as the exact engine specifications evolved. Compression ratio is 10.3:1 for engines built prior to model year 2000, and 10.0:1 for those built afterwards. The 1998 revision is quieter than previous Northstar engines, due to hydraulic engine mounts, and performs better due to a tuned intake system. Most LD8 Northstars are rated at and . LH2 (VIN "A") The Northstar was designed originally for transverse front-wheel drive applications. It was modified substantially in 2004 for longitudinal rear- and all-wheel drive use in the STS, SRX, and XLR, as well as receiving continuously variable valve timing on both intake and exhaust sides. The RWD (LH2) Northstar produces and . The addition of variable valve