New Delhi: The stunning features of the US Presidential vehicle makes it clear why the Secret Service wants to unleash the 'Beast' during President Barack Obama's Republic Day outing in Delhi.

If Obama does indeed follow the protocol and arrives with President Pranab Mukherjee at Rajpath, he will possibly be the first US President not to travel in his own highly secured bomb-proof vehicle referred to as 'The Beast'.

Ever since the assassination of President John F Kennedy who was riding an open top Lincoln Continental, the United States has pulled out all stops to make every succeeding Presidential vehicle virtually impenetrable.

The Beast is no different with its eight-inch thick body armour plating and five-inch thick bulletproof windows which insulate the President from all sorts of threats including chemical attacks.

Its doors weigh similar to those on a Boeing-757 aircraft.

The eight-tonner runs on shred and puncture resistant Kevlar-reinforced tyres with steel rims underneath which ensure that the vehicle does not come to a halt even if its tyres get damaged.

Even the fuel tank is covered with a special foam that negates any possibility of an explosion.

Apart from acting as a security shield for the President, the imposing vehicle has also been used to make political statements by successive Presidents.

In the recent past, Obama had the vehicle's number plate carry the message 'Taxation Without Representation' to reflect the demand of the citizens of Washington DC to have representation in the US Congress.

The Beast, based on a Cadillac DTS is the first Presidential limousine not to have a specific model name.

The vehicle is an amalgamation of features sourced from different vehicles under the General Motors brand with its chassis, doors, headlights, side mirrors and door handles having different origins.

Despite the oft-cited declarations of invulnerability, 'moving fortress' is not as invincible as it would seem, with the car showing a penchant for breaking down for unknown reasons several times in the past.

US President Barack Obama's replacement ride in Jerusalem, after his original car broke down (Photo: AFP)

During the President's state visit to Israel in 2013, the car broke down and had to be ingloriously towed away atop a truck.

Environmentalists also scoff at the vehicle's predilection for consuming fuel at a very high rate giving a mileage of 3.4 km per litre.

While the Beast may be the centre of attraction, the Indian Presidential vehicle packs quite a punch as well.

Since 2012, the President of India travels in a heavily armoured black Mercedes Benz S600 (W221) Pullman Guard. The armour is designed to protect against military rifle shots, bomb shrapnels and other explosives.

A Mercedes Benz S600 (W221) Pullman Guard