Noisy, don't know why engine is having so much of noise,
when I compare with any other cars.
This may be manufacturing defects, I came to know similar comments from others as well.
2012 Nissan Altima Overview
The 2012 Nissan Altima is a front-wheel drive, midsize car with room for five. A coupe variant is also available. The 2012 Altima sedan is available in 2.5, 2.5 S and 3.5 SR editions. The coupe is available in 2.5 S and 3.5 SR editions.
Two engine choices are available with the Nissan Altima. A 2.5-liter four-cylinder engine rated at 170 horsepower and a 3.5-liter V6 engine that makes 270 horsepower. Both engines are paired with a continuously variable transmission (CVT).
When equipped with the four-cylinder engine, the 2012 Nissan Altima is EPA-rated at 23/32 mpg city/highway. When outfitted with the V6 engine, this car is rated 20/27 mpg city/highway. Both models take regular grade gasoline.
All Altima models are outfitted with a distinctive t-shaped grille and intermittent wipers. Standard steel wheels give way to available aluminum alloy wheels on higher trims. All-season tires are included. Halogen headlights are standard and HID lights are optional with the 2.5 S and 3.5 SR editions. Fog lights are available except in the base edition.
The interior of the Altima sedan is roomy and offers very good seating for five. The coupe also offers room for five, but legroom is tighter than in the sedan. Both models have front bucket seats and a rear bench seat.
Cloth seats are standard; leather is available. A six-way manual driver's seat becomes an eight-way power seat in the 3.5 SR edition. The sedan offers far more cargo carrying capacity than the coupe with 15.3 cubic feet of storage room. The coupe's trunk is cramped, measuring just 8.2 cubic feet. The rear seat in both body styles folds, providing access to the trunk.
A standard four-speaker audio system comes with the base model, while higher trims get a six-speaker system. A USB port is also included with upper trim level editions. Available option packages bring in dual-zone automatic climate control, a power sliding moonroof, a rearview monitor, satellite radio, a rear spoiler, navigation and upgraded wheels.
In crashworthiness testing conducted by the Insurance Institute for Highway Safety (IIHS), the 2012 Nissan Altima sedan scored top marks in moderate overlap front and side testing. The sedan registered acceptable scores in two other categories: roof strength and head restraints and seats. All models come with a suite of air bags, an anti-lock braking system, stability and traction control and a tire pressure monitoring system.