Volvo S70

By the late 1990s, Volvo had adopted a new design philosophy with the C70 coupe and convertible. This shift also introduced a new model naming system: "C" for coupe and convertible; "S" for sedan; "V" for station wagon; and "XC" for "Cross Country" SUVs and elevated wagons.

During this period, the P80-based 850 sedan and wagon were updated both stylistically and technically to remain competitive. Consequently, the revised 850 sedan was introduced in 1998 as the S70, positioned below the S90 in Volvo's model lineup.

The S70 was offered in the U.S. market with entirely "white block" five-cylinder engines. Among these engine options were a naturally aspirated 2.4L (with some early models having a 2.5L), a low-pressure turbo 2.4L "GLT," and a high-pressure turbo 2.3L "T5." Power was transmitted to the wheels via the 5-speed manual M56, the 4-speed automatic AW50-42/43, or the AW55-5X SN 5-speed automatic (available in naturally aspirated models after 2000).

The S70 and V70 underwent significant changes as Volvo rapidly transitioned into the new millennium. The introduction of the Motronic ME7 engine management system in 1999 enabled electronic rather than cable control of the throttle; this was achieved through actuators and sensors that replaced traditional throttle cables. These later P80 vehicles featured a "partial network" system where various electronic control units communicated over a common network to manage multiple functions.

These models were the first Volvo vehicles to offer an AWD (all-wheel drive) option. The viscous coupling in the rear engaged the rear wheels when the front wheels began to slip. Inside the viscous coupling, alternative disks rotating between the front and rear axles operated with a special fluid. This fluid thickened as temperature increased, causing the disks to stick together and activating the rear wheels.

The AWD system was only available on automatic LPT S70 models, making the AWD-equipped V70 and V70 XC models more common.

AWD failures typically arose from issues in three main areas: the angle gear mounted next to the transmission, the arm connecting the angle gear to the transmission, and failures in the viscous coupling. While the oil and seals in the angle gear could be replaced, replacing the arm required the angle gear and the passenger front axle to be removed. The viscous coupling was a closed system, so when it failed, it was generally replaced with a second-hand part.

The S70 and V70, as updated versions of the P80 platform that was used for a decade, were produced only until the introduction of the completely new P2-based S60 and V70 models in 2001. Although these late P80 vehicles shared many common features with later digital Volvos, they are remembered as the last representatives of the classic "boxy" Volvos.

The first-generation S70 was a facelift of the 850 sedan, utilizing the P80 platform as a four-door sedan, and was sold in the U.S. from 1998 to 2000.

U.S. models were equipped with inline 5 gasoline engines. Low-pressure turbo models featured the 2.4L "2.4T/GLT" engine with front-wheel drive and both manual and automatic transmission options, while AWD versions came solely with automatic transmission. High-pressure turbo models used the 2.3L "T5" engine. Naturally aspirated models were offered with either 2.4L or 2.5L engine options in front-wheel drive.

The transmission options included:

• M56 5-speed manual

• AW50-42 4-speed automatic

• AW55-5X SN (FWD) 5-speed automatic, available only for 2000 model year naturally aspirated vehicles.