Michael Schumacher, Fernando Alonso, Kimi Raikkonen and perhaps one day, Lewis Hamilton – Formula One (F1) World Champions who take speed and racing to the maximum in pursuit of motorsport glory.
Drivers who push themselves, their teams, and ultimately their finely tuned, multi-million dollar race cars to the limit. Drivers who are ‘cooking on gas’ all around the world as they race on what are often nitrogen-filled tyres.
When thinking of motorsport it’s easy to conjure thoughts of the sheer speed, attractive aerodynamics, lightweight composite construction, and high octane engines. Yet behind the technical masterpiece that is the modern F1 car, the application of industrial gases is arguably in pole position as a race car’s single biggest performance variable.
The typical tyre of an F1 car, as also applicable throughout many formats of motorsport, is produced to be as lightweight and strong as possible and last for an average distance of around 200km. This could involve anything from one tonne of downforce, 4g of lateral load and 5g of longitudinal load constantly being inflicted upon the tyre throughout its racing life.
To cope with this, the rubber tyre is constructed in a nylon and polyester structure that forms a complex weave pattern designed to withstand such forces. Perhaps more important, is what actually goes inside the tyre.
The three fundamental components of a rubber tyre are carbon, sulphur and oil, but the role of gases in these areas is probably an article for another day. What’s key is the nitrogen employed in the air mixture inside the tyre, a trend that appears to be increasingly finding favour outside the realm of motorsport too.
Beyond the soft or hard rubber compounds lined-up on the grid, a specialist nitrogen-rich air mixture fills the tyre – designed to minimise variations in tyre pressure through temperature, while also retaining the pressure longer than ‘normal’ air does.
Nitrogen molecules are much less likely to escape the inside of a tyre wall, compared with traditional air mixtures, and is also perceived to offer the benefit of higher quality due to its inert nature and lack of moisture or oxidation properties.
Nitrogen gas air mixtures have long been the accepted medium of choice for filling both aircraft and racing tyres, such as those blistered by motor racing greats like Nigel Mansell, Michael Schumacher, Ayrton Senna, Mika Hakkinen and Fernando Alonso.
The rubber tyre is essentially a complex membrane through which oxygen permeates around three times faster than nitrogen, placing the use of regular compressed air, containing 21% oxygen and 78% nitrogen, at a considerable disadvantage. Oxygen slowly leaks out through the rubber walls and the resulting under-inflation causes increased tyre wear – as well as reduced fuel economy.
In the high-tech, ultra competitive and seriously high-precision world of F1 racing, it’s no wonder that high purity nitrogen-rich air mixtures are believed to have overtaken compressed air as the front-runner option for tyre filling.
The multi-billion dollar, mega money F1 industry invests huge resources in ongoing engine development, aerodynamics, lightweight design and a whole plethora of other finely honed cutting-edge technologies. Heavy resource is also ploughed into the development of tyres, optimising tyre efficiencies and performance, and best adapting to the ever-changing rules and regulations governing race weekend tyre management.
So important is the careful management of tyres that a single pit-stop, miscalculated tyre selection or ‘flat-spotting’ of tyres through wheel lock-up can mean the difference between victory and podium finish, point-scoring and back-marking, and ultimately – Championship victory or failure.
After years of competition with fellow manufacturer Michelin, Japan’s Bridgestone began the 2007 F1 season as the sole supplier of tyres for all teams in the paddock and in many respects, levelled the playing field of tyre selection from the teams on the front row of the grid to those off the pace at the back.
Getting the right type of inflation is essential not only in F1, but also in the ‘feeder’ GP2 Series and on two wheels in MotoGP. While Bridgestone indicates that it uses simply dried air, the company notes that eradicating moisture is a significant factor for tyre inflation and racing teams themselves may actually re-fill the tyres with gases such as nitrogen.
Hirohide Hamashima, Director of Motorsport Tyre Development for Bridgestone, exclusively told gasworld, “Bridgestone’s F1, GP2 Series and MotoGP tyres are inflated with dried air. This is to ensure there is no moisture in the tyres which could ultimately affect the tyre pressure and therefore handling of the tyre.”
“It is important to use a non active gas for inflating tyres to avoid any reaction with the rubber.”
Noting that the inflation provided may not always be the choice that arrives on the track on race day, Hamashima added, “Some teams do replace the dried air with alternative gases and, like IndyCar tyres, the purging helps also to ensure no moisture. However, while using nitrogen and carbon dioxide can be better for maintaining road tyre pressures, race tyres are used for such short periods of time that using these gases in racing tyres has less effect.”
This is a point echoed across the Atlantic in the US, where the IndyCar Series is supplied with a similar tyre, only for a team’s preferred gas selection of nitrogen for example, to be implemented instead.
Moisture or vapour is again cited as a fundamental factor, as Dale Harrigle, Senior Project Engineer of Race Tyre Development for Firestone Racing, explains, “The Firestone racing tyres (for IndyCar), as we supply them to the teams, are inflated with dried air from our trucks.”
“However, nearly all of the teams replace our dried air with nitrogen. Due to the method used to bottle the nitrogen, it is 100% free of water vapour. The fact that there is no water vapour in the tyre causes the tyre pressure to be more consistent over a range of temperatures.”
Purging of the tyre is almost an added advantage for motor racing teams, as Harrigle concluded, “Purging the dried air and replacing it with nitrogen also helps to dry the tyre and remove any water vapour that may have been inside the tyre when it was mounted.”
Picking up the slipstream
Much of the technology from the world of motor racing gradually filters down into the wider consumer vehicle market, with traction control, double clutch paddle gearbox systems, and nitrogen-filled tyres just a few examples of this.
Though there exists some genuine technical crossover, race tyres and road tyres have remained largely distant cousins until now. The average consumer car tyre is designed to be economical and durable, engineered to clock-up a life of 16,000km (10,000 miles) or more, compared with the 200km life of high-performance racing compounds.
The racing tyre is also formulated from incredibly soft rubber compounds which offer the best possible grip against the varying texture and temperature of the race track, wearing quickly in the process.
Now appearing to pick-up the slipstream of race tyre technology however, is the conventional vehicle tyre.
Distant cousins they may well be, but the use of nitrogen in the tyres is bridging the gap between consumer compounds and performance racing versions – bringing the tyre family closer together. As ever demanding societies and economies strive to improve, the emerging trend in the wider automotive arena is for nitrogen-filled tyres in the public domain around the world.
Where are nitrogen mixtures in use around the world?
Large-scale commercial vehicles have long campaigned the merits of nitrogen gas-filled tyres, with Parker Hannifin Process Air and Gas among a number of companies to laud the technology’s improved safety and efficiency impact.
In October 2007, Bridgestone Tyres Queensland revealed it would be introducing nitrogen refilling for fleet operators in an Australian first. The announcement came as the company joined forces with specialist nitrogen inflation company Nitroman, to bring tyre maintenance and extended shelf life to fleet operators.
James Ryall, Commercial Sales Manager for Bridgestone Queensland, noted back in October, “At Bridgestone we believe nitrogen has a place in tyre maintenance and extending shelf life.”
More recently, Nissan has further highlighted the trend for nitrogen-enhanced tyres with the news that its GT-R production cars would arrive in the US for their June 2008 debut, with nitrogen-filled tyres.
Furthermore, the company declared that none of its US dealerships would be certified to sell a new GT-R unless it could provide access to nitrogen, in order to maintain the run-flat tyres’ peak factory issue condition.
Nissan clearly endorses the use of high-purity nitrogen in road tyres then, a trend that has been promoted through NASCAR and the Mario Andretti Racing School in the US.
With gases so prevalent in the fast lane, it’s not inconceivable that we could see a nitrogen-powered Lewis Hamilton or Robert Kubica as future F1 World Champion. Nor would it be unreasonable to think that we may all soon be driving on nitrogen gas-filled tyres in a future ‘hydrogen economy’.