Ahead of its speculated release later this year, the 2016 Toyota Prius has been spotted roaming the streets of San Francisco, California. The upcoming model is the fourth iteration to the Japanese automaker's hybrid mid-size hatchback series. Recently, a video surfaced online portraying the alleged vehicle covered almost entirely in camouflage.

Toyota's gasoline-electric hybrid car has come a long way. The first Prius model was released in 1997 and since its inception, the model has been recognized as one of the best fuel economy vehicles in the United States. As of 2012, the Prius family prides itself with three models being in the top 10 most fuel-efficient cars sold in the US, according to the Environmental Protection Agency (EPA).

It has been six years since we last saw the Prius being updated. Now, it appears that the 2016 Toyota Prius will still be the environment-friendly vehicle it's been known for, but with a host of welcome improvements and new features.

As mentioned, the upcoming Prius was reportedly captured in video while being tested along the roads of San Francisco. The video in question was uploaded in the PriusChat.com forums by a user named "priusfan500."

Upon close inspection, the video shows that the car's main glasshouse still has the usual Prius styling signature from the side. Even though it's covered in a lot of disguise, it's evident that the model's designers have given it a more fastback-look judging from the slanted back window and tall, nearly upright tail.

The clip also provides a quick view into the 2016 Toyota Prius' interior. Several frames in the video show that the fourth-generation hybrid appears to sport a centrally mounted instrument panel, similar to that of its predecessor.

The upcoming model is said to be based on the car maker's new Toyota New Global Architecture (TGNA). It means that the 2016 model will feature a lower center of gravity, a sturdier structure, and will likely gain a longer wheelbase to increase passenger space.

Although the 2016 Toyota Prius is rumored to grow 70mm longer and 25mm taller, resulting to 4.55 meters in length and 1.77 meters in height, Car Advice reported the upcoming Prius is expected to lose approximately 100 kilograms of weight.

Apart from this leaked video and supposed specs, a separate report last month from AutoNet, a Taiwanese publication, suggested that the vehicle's hybrid system will comprise of a 75kW 1.8 liter petrol engine, amounting to a total combined output of around 110kW. That corresponds to fuel consumption improvements of about 7 to 8 percent.

Some petrolheads may think that with this amount of camouflage and the car maker's unwillingness to divulge details, the 2016 Toyota Prius is still a long way off. However, the fourth generation Prius is actually expected to be unveiled this November during the LA Auto Show. According to CarScoops.com, the new hybrid car could go on sale in the United States before 2015 ends.