The other component of keeping cars on the track is mechanical grip: this relates to the tyres and to the way in which the suspension is set up. Tyres are low profile (not much tyre-wall is visible) or some other measure, depending on the current rules. Taller tyres have more flexibility in the tyre wall which means that the car can move laterally while the tyres stay in a straight line, relative to the road. Everyone dislikes lateral movement in tyres: the aero engineers say that they can't predict where the airflow will go, drivers complain that the car won't handle properly in corners and not only wobbles about but sliding is unpredictable. But the option is ultra-low-profile tyres that take a serious beating and break up and/or wear out under the hostile driving conditions that racing creates.

Worse, tyre life is affected by steering geometry (that is the direction that the front wheels are set to when the car is stationary: oddly, they rarely point directly ahead) how they are set in the vertical plane. Other suspension settings also make a difference as to how much tyre is on the road and which part of the tyre sits flat on the straight, on left or right corners and even at different speeds.

But both aero and mechanical grip are at the heard of some of the things that are most wrong with F1.

Aero disturbs the air all around the car. Teams spend vast amounts of money to direct that air where it does the most benefit, and creates the least drag. Drag is two things: it's the fact that the car uses energy to move the air aside so that the car can pass. Think of what it's like when you freewheel your bike down a hill: even at fifteen kilometres an hour you can feel the pressure of the air on your face. This is why fast trains have pointed snouts: they use less power to reach higher speeds than they would if they had flat faces. So fast cars are designed to encourage the air to move aside rather than to act as a blocking force. So far, so good. As the air flows over, under and around the car it performs a variety of functions: cooling components, keeping the car on the ground, etc. But how effectively it does those things depends not only on the design of the car but also the environment it works in. What works in a wind tunnel might not work very well on a racing circuit and what works on the straights won't work in the same way in corners, what works in hot air won't work the same in cold air (it's about density and height above sea level and humidity also play a part) and, of course, what works on the open road won't work in the same way in a tunnel or, crucially, if there are other cars directly in front.

But there is another type of drag: after the air has passed the car, there is a small space behind the car where there is a vacuum: it is here that the air rushes back in after the car has passed and it creates a suction effect. In road cars, good design allows the air to pass over the car and keep the rear window clear, on hatchbacks, the brick-like rear creates strong suction and road dirt and rain are pulled back onto the rear-window, which is why hatchbacks and estate cars have rear-wipers and saloon cars do not.

That empty area into which air is being sucked is used in racing for what is called "slipstreaming." In simple terms, what it means is that a car following closely behind another car can get a double benefit: the first is that the car in front is using its energy to make the hole in the air whereas the second car doesn't have to make that hole; the second is that, as the air rushes back in, it sucks the closely following car along. As a result, the following car can use less power to keep the same speed then, at the end of a straight, when the first car slows down, the second car can pop out, use the additional power that was in hand, and overtake under braking. Sometimes the difference is enough for passing on the straights.

However, as we'll see tomorrow, aero creates as many problems as it solves.