Deeper grooves improve traction for off road use but are noisy when on road use.
Because they have to get a grip in mud, grass and soft ground in general.
so they can have more traction
When it rains, cars sometimes hydroplane because the water underneath the tires supports the weight of the car and causes it to loose traction. Grooves give another channel for water to escape. As for off-road cars, the tire grooves are not much deeper rather they are larger and have more room to go up and down. In my Jeep Wrangler, the tire grooves are the same depth as an Acura TL and a Honda minivan. Maybe on other off-road cars they help the car travel through gravel, rock, sand, and snow to gain more traction.
Really depends on the car, there are great offroad cars with automatic.
if there is no grooves on racing cars tyres then the cam attempt to an accident while drifting 1.car can move out of track as it takes turn at speed of more then 60 km ph 2.car can take air trams(take flips in the air) 3.reduce sprrd and bad starting
Tires need the grooves to be able to get a grip when weather is not the best. They provide a place for water, ice and snow to go and allow the rubber tread to make contact with the road. Racing cars often use tires with no grooves at all, but the weather has to be dry and the pavement clean. On a passenger car, even a little water can cause hydroplaning, where the tire is on water rather than the pavement.
If they are normal cars there will be 104 tires
There is usually never a benefit from the grooves but to give the car a sleek and "cool" look and more appealing!
Since cars were first made tires were always rubber.
A burn out will ruin tires on race cars by burning up the rubber. The rubber of the tires will get worn from the friction of the pavement causing the tires to tear.
Race cars use tires with no grooves (or 'Slicks') as they provide the most surface area contact with the road which provides the most grip. More grip = more stability. The slicks are only used when the track is dry enough as they will not clear away water, they are more likely to lose contact with the track and hydroplane/aquaplane, which will cause a loss of grip. In Formula 1 when the track becomes too wet for slicks they will change tires to either Intermediate or Wet tires which feature different depth grooves for driving on a wet track. A road car cannot use slick tires as it must be suitable for driving in any condition at any given time, plus all 4 tires of a Formula 1 race car can be changed in a little more than 2 seconds, I doubt you'd be able to manage that with a road legal vehicle.
Many European cars use 14 inch tires.