The 2019 Nissan Altima Will Offer a New Variable-Compression Engine

author: Eric Walz   

Although much of the automotive industry is focused on developing electric powertrains, there is still improvements to be made with the traditional internal combustion engine for increased efficiency.

Nissan has such made progress with this by designing a new variable-compression (VC) engine. Nissan first announced the engine option in the 2019 QX50 crossover. The new engine will now be available in the 2019 Altima sedan, which Nissan debuted and the New York Auto Show this week.

By having this new engine widely available, the Altima offers the potential for Nissan to expand the reach of this variable-compression technology.

The engine can adjust its compression ratio between 8:1 and 14:1 automatically, provided high-compression efficiency under light loads and low compression needed for turbocharged power under hard acceleration.

Inside the engine, a pivoting mechanism where each piston attaches to the crankshaft can be rotated to alter how high the piston reaches at the top of each upward stroke. In addition, the system reduces friction by altering the angle of the connecting rod on the downward stroke. Fo further efficiency, complex fuel and exhaust routing help to maximize the engine's efficiency.

Nissan said the new variable-compression engine will be offered as an option in the Altima SR and Platinum trim levels. With 248 hp and 273 lb·ft (370 N·m), the VC-Turbo supersedes the previous Altima 3.5-L V6 traditional engine that engine generated 270 hp and 251 lb·ft (340 N·m).

For the VC-Turbo, effective compression ratio can be varied between 8:1 and 14:1 and premium-unleaded gasoline is recommended. Nissan said a display in the digital gauge cluster will indicate the VC-Turbo's operational state.

Nissan will continue to offer a normally-aspirated 2.5-L DOHC I-4 that generates 188 hp and 180 lb·ft (244 N·m). There are numerous engineering upgrades that include direct injection, intake variable-valve timing, a tumble-control valve, a variable-displacement oil pump and cooled external EGR.

The transmission for both engines is Nissan's long-established Xtronic continuously-variable transmission, with SR-trim models including manual-shaft capability.

With sales for the all-new Altima not beginning until this fall, Nissan officials said the company is not yet ready to project fuel-economy ratings for the new VC-Turbo engine. The previous-generation Altima with the 3.5-L V-6 is rated at 22 mpg in the city and 32 mpg on the highway and 26 mpg combined.

To accompany the 2019 Altima, powertrain changes the first ever all-wheel-drive option. The company said the Intelligent All Wheel Drive system can apportion torque in a range from 100% to the front axle to a 50/50 split between front and rear axles.

In a press release, Nissan said that AWD is beneficial to customers in winter weather regions—and may attract buyers who are comtemplating buying a small SUV in order to get an all-wheel-drive option.

"The lack of available all-wheel drive has also been a factor in buyers who prefer sedans switching to compact SUVs," said José Muñoz, chief performance officer, Nissan Motor Co. Ltd. The AWD system will not be available with the VC-Turbo engine, however.

Nissan's ProPILOT Assist

In addition, the 2019 Altima is equipped with Nissan's ProPILOT Assist advanced driver-assistance system, which Nissan said "is the foundation for the autonomous vehicles of the future, helping drivers stay centered in the lane, navigate stop-and-go traffic, maintain a set vehicle speed and maintain a set distance to the vehicle ahead."

ProPILOT Assist employs a forward-facing camera and radar and other sensors, as well as a dedicated ECU, to help keep the vehicle centered in the driving lane, as well as maintain the set speed with adaptive cruise control that can react to leading vehicles in the same lane. The system is standard for SV, SL and Platinum trims.

The 2019 Altima also has standard Rear Automatic Braking to apply the brakes when reversing if an object is detected, as well as a traffic-sign recognition system that alerts the driver when a traffic light turns green.

Eric Walz

Originally hailing from New Jersey, Eric is a automotive & technology reporter covering the high-tech industry here in Silicon Valley. He has over 15 years of automotive experience and a bachelors degree in computer science. These skills, combined with technical writing and news reporting, allows him to fully understand and identify new and innovative technologies in the auto industry and beyond. He has worked at Uber on self-driving cars and as a technical writer, helping people to understand and work with technology.