NEW 1999 HYUNDAI SONATA OFFERS CHOICE OF TWO WORLD-CLASS ENGINES AND NEW TRANSMISSIONS

The 1999 Hyundai Sonata has been re-engineered from the ground up. This reengineering included the development of two world-class engines that represent a major technological advancement for Hyundai.

Standard equipment is a 2.4-liter, DOHC engine. Developing 149 horsepower at 5,500 rpm and 156 ft./lbs. of torque at 3,000 rpm, it's one of the largest, most powerful four-cylinder engines in the Sonata's class.

Standard on the top-of-the-line GLS model is the all-new Delta V6 engine - the third engine completely designed and engineered by Hyundai. It's an aluminum 2.5-liter, DOHC engine that develops 170 horsepower at 6,000 rpm and 166 ft.Abs. of torque at 4,000 rpm. The sophisticated Delta engine incorporates numerous technological advancements, resulting in an exceptionally smooth, refined powerplant.

Strong, silent type
Compared with its predecessor, the Delta V6 is lighter, more efficient and more economical. It features an all-aluminum block and head, with 60-degree bank angles. Overall weight is 334 pounds - 20 percent lighter than its predecessor. Pressed-in dry steel cylinder liners and a cast-aluminum oil pan were used for improved durability. With a compression ratio of 10: 1, it develops satisfying torque output over a wide rpm range.

Engine noise and vibration have been significantly reduced. Hyundai engineers equipped the new Sonata with hydraulic engine mounts, greatly reducing the amount of noise and vibration transmitted to the chassis. The result is an engine that is exceptionally quiet.

The heart of the Sonata's V6 engine is an advanced engine management system. This state-of-the-art computer system integrates fuel and ignition controls, providing maximum performance and economy while reducing emissions. A key part of this system is a Powertrain Control Module (PCM) with titanium-oxide sensors that monitor all major systems that affect performance, emissions, economy, smoothness and durability. Separate from the PCM is a sophisticated Transmission Control Module (TCM).

What's unique in the Sonata V6 is a Control Area Network (CAN), which connects the PCM and TCM (and the optional antilock braking/traction control system) into a true network. Important data passes freely in all directions. This enables the PCM to use data from the TCM to improve driveability during automatic transaxle shifts, resulting in smoother torque, shifting and braking, as well as more efficient overall operation. Likewise, the TCM uses data from the PCM to help select the optimal shift points during acceleration, deceleration, or climbing or descending hills.

As an example of how the Control Area Network functions, when the coolant temperature sensor indicates the engine is cold, the automatic transaxle shift points are delayed to encourage quicker warmups. This also helps heat the catalytic converter faster, resulting in quicker closed-loop operation and reduced emissions.