One of my pleasures is watching Formula 1. I am not sure why I enjoy it so much. The best I have come up with is that there is no doubting the result on the track. Well, that is until recently. Something bizarre is going on in Formula 1 that makes no sense to me. It all has to do with the tyres.
It is a little-known fact that I was a tyre fitter for the Avon Racing team after I left school. I would tour the race tracks of Europe and spend long periods in the back of trucks changing race tyres for what was then Formula 3000 and Formula 3. It seems very exciting when you talk about it, but it wasn’t very interesting.
That experience and a degree in materials engineering got me thinking about the recent debate between Pirelli and drivers about heating blankets on tyres. Pirelli wants to remove the heating blankets to meet some random target set for 2030 for Net Zero. The aim, I believe, is to reduce the carbon dioxide released into the air. They talk about Net Zero goals. What are these goals net of?
Net Of What
I decided to do a bit of investigation to understand what their goal was. I turned to the Pirelli website and did a search on tyre blankets. It was blank. I then thought to look at the Formula 1 website. That does not even have a search function so I gave up on that.
With the easy route to an answer blocked, and clearly no desire for Pirelli to be transparent about their goals, I decided to do a bit of work on the back of an envelope. Strap in, this could get bumpy.
How Many Tyres?
I started on the Formula 1 website with the following:
“A Formula 1 car is given 13 sets of dry weather tyres, four sets of intermediates, and three sets of full wets. An extra set of soft tyres is reserved for those who reach Q3, while all drivers must use at least two different slick compounds in the race, providing the track is dry.”
All the race cars together will use approximately 270 sets of race tyres (10 teams x 13 sets + 10 teams x 14 sets) in a weekend. I say approximately because all teams may not use all their tyres, plus if there are mixed weather conditions more may be used. For our purposes, I will say that 1,080 tyres are used at each Formula 1 race, with 22 races this year, which is a total of 21,600 tyres consumed in one season (approximately).
What Are Tyres Made Of?
To understand the relative impact of these heating blankets, we first need to understand the basic building blocks of a tyre. If you are not sure why, hang on, we will get tho that.
Here we go – I will keep it as simple as possible.
Rubber – No Surprise There
Tyres are an incredible combination of materials. The bulk of the tyre is manufactured from rubber, but what is rubber? There are two kinds of rubber: natural rubber and synthetic rubber. Natural rubber is easy, tapped from rubber trees that grow in tropical areas. The sap is harvested from the trees and dries to a rubbery consistency. This solid has the chemical composition of C5H8. That is correct; just carbon and hydrogen. This molecule is referred to as isoprene and is a monomer.
Synthetic rubber is manufactured from oil residue once the valuable parts have been extracted. The valuable parts are the fuels, principally petrol, diesel, and aviation fuel. Synthetic rubber will arrive with a few extra components in there, for example, sulphur but also other monomers that are similar to natural rubber isoprene. The variation in the monomers will provide different physical properties, depending on the mix.
In a standard car tyre, nearly 30 different rubber compounds are used. You may think there is a single rubber compound throughout the tyre, but the tread rubber differs greatly from the sidewall rubber.
But don’t forget, all these rubbers are just carbon and hydrogen in various chemical permutations and combinations.
Vulcanization Materials and Fillers
These are the compounds that make the magic happen. When a tyre is manufactured, the rubber goes through vulcanization. This describes the process where the monomers (in this case, isoprene) are all linked together to create polymers or long chains of monomer molecules linked together. In rubber, the chemical that acts as the polymerization agent is sulpher. The sulpher atoms act as nodes, allowing many monomers to link together and create polymers. This makes the rubber stronger and more durable.
But for a car tyre rubber there is more. They have fillers that also change the physical properties of the rubber. The most common are silica (sand) and carbon black – just pure carbon. By manipulating these key ingredients, many different rubbers, with very different physical properties can be created for various parts of the car tyre.
When you look at the side of a tyre it will typically refer to several “plies.” This refers to the number of textile layers used to construct the tyre case. These plies provide structural strength to the tyre, and are most commonly made of nylon. And nylon is manufactured, in a polymerisation process, from oil. When anything is manufactured from oil, you can assume it is just carbon and hydrogen atoms in various chemical permutations.
High Carbon Steel
We have talked a lot about steel in the manufacture of watch cases, but as one of the most important structural materials in the world, it is not surprising to find it in a tyre. There are two places high carbon steel is used in the tyre construction. The first is in the bead of the tyre. The second is the steel belt which is key to the structural strength of a radial tyre (which almost every tyre is these days). The steel is bronze coated high carbon steel rope wound into circles to manufacture the bead or to create a rubber sheet with steel ropes.
How Much Do They Weigh
How Much Energy To Heat Them
Now we understand what a tyre is made of we are able to estimate the energy required to heat a set of tyres. There are many estimates here, but my purpose here is not specific accuracy but to provide a relative understanding of the energy impact of heating the tyres.
The tyre blankets are set to heat the tyre and wheel assembly to 80oC and hold it there. We shall assume a starting temperature of 10oC each time to be conservative. This means the tyre needs to increase in temperature by 70oC. For the three key components of the tyre we need the specific heat capacity of each item.
Aluminium Specific Heat Capacity 900 J/Kg-°C
Steel Specific Heat Capacity 620 J/Kg-°C
Energy for Aluminium = 900 * 10 * 70 = 630KJ
Energy for Steel = 620 * 10 * 70 = 434KJ
Energy for Rubber = 440 * 30 * 70 = 924KJ
So the total energy required to head a set of Formula 1 tyres, ideally, is 1,988KJ. Believe it or not, this is not a great deal of energy, it is equivalent to running a 1KW heater for 1.988 seconds. Not a lot. It is how this energy is applied to the tyres that really consumes the energy.
Other factors outweigh the energy necessary to heat the tyres. Thermal losses, energy losses in the heat blankets, and the entropy of the operation a large in comparison. In this case, the tyres are generally heated for 2 hours, an hour before and then through the racing session.
Heat losses are proportional to the temperature gradient between the ambient temperature and the temperature inside the heat blanket. That means the colder it is, the more energy is required to heat and maintain the temperature of the tyres.
As an estimate each heating blanket has a power rating of approximately 1KW – or 1,000 Joules per second. NOTE: This is my estimate of the power of a tyre blanket. I have tried to find a reference for this but so far failed. If anyone knows the power rating for a tyre blanket, I would be very interested to know.
How Much Energy Used Over A Weekend Heating
There are 1080 race tyres that require a 1KW heater to run for 1 hour total (it will cycle), each for five sessions over the weekend. I think this is an overestimate because for every session, not all tyres will be heated. This is now a pretty simple mathematical problem:
1080 * 1 * 1 * 5 = 5,400KWh of electricity to heat the tyres. Last month I used 500KWh of electricity in my home. So the electricity used to heat the tyres is approximately the electricity used by 11 homes in one month.
What Should We Be Comparing?
This whole discussion is about “Net Zero.” From what I understand the drive is to reduce the amount of carbon dioxide being released into the air. In the US the average CO2 emission per KWh of electricity produced is 0.855lbs or 389 grams. Over the weekend, my estimate is that the tyre blankets create about 2,100 kg of CO2 emission.
What Happens To The Tyres After They Are Used?
I would accept that this is a lot of energy, and thus CO2 to put into the atmosphere if it were not for the fact that all these tyres are burnt at the end of the race. This is what Pirelli says about the used tyres.
“Used F1 tires are transported to the Pirelli logistics center in Didcot, England. They are crushed, sent to cement companies, and burned to fuel boilers. The material produced in this process can also be used for road surfaces and other industrial applications.”
The question then is, when these tyres are burnt, how much CO2 is released into the atmosphere. Well here we need to go into strange areas of chemistry but if there is 10 kg of rubber in each tyre then the calculation is as follows:
Unfortunately, this gets a bit technical, I am not going to explain it in detail, but I lay it out here for completeness, in case someone spots a mistake!
Isoprene has the chemical formula C5H8, this is a molar mass of 68. In 10 kg of rubber there would be 147 moles of Isoprene. This will include 147 * 5 moles of Carbon, which is 735. (There are 5 carbon atoms in each isoprene molecule)
CO2 has a molar weight of 44, this means that burning one Formula 1 tyre will create approximately 32 kg of CO2 (735 x 44 = 32,340 grams). Thus a single-race weekend will create about 34,560 kg of CO2 into the atmosphere (1080 x 32 = 34,560 kg).
What Are Pirelli Trying To Do?
If you have made it this far and are scratching your head, then you are with me. I have no idea what Pirelli are trying to do with the attempt to remove heating blankets. The tyre heating is about 6% of the CO2 the tyres create when burnt at the end of their life. Pirelli could reduce the carbon dioxide going into the atmosphere by making longer lasting tyres and giving the teams one set fewer.
Coincidentally, that would also reduce the energy required for heating the tyres, as there would be less of them!
One would think that a company of Pirelli’s size would have a rational discussion for removing the heating blankets on their website. As I have shown above, they have nothing. I cannot find a single objective reason, with measurable targets to justify this headlong rush to remove the heating blankets. Except for a blind desire for Net Zero by 2030, whatever “Net Zero” is?
What Is Really Going On
I see a load of marketing posturing—social signaling for the narrative of the moment. The fact is that carbon dioxide is 0.04% of the atmosphere (400 parts per million). I am astounded by how few people know this. Nitrogen and Oxygen comprise over 95% of the air around us. How can the variation of a gas that is such a small fraction of the atmosphere impact the long-term trajectory of the earth’s temperature?
Less than 10% of the 0.04% of carbon dioxide in the atmosphere is caused by human existence on the earth. Not to mention that carbon dioxide is critical for plants to thrive through photosynthesis.
If Pirelli and Formula 1 are worried about carbon dioxide in the air, they should make fewer, better tyres and be extremely transparent about their absolute goals. They should not be trying to fudge the numbers with “Net Zero” – can anyone tell me what the Zero is Net of?
I do not think that is what Pirelli or Formula 1 want. They want you to believe a narrative without objective evidence. Was that what Omega was trying to create with the auction results for the Frankenstein Speedmaster? They have a narrative they wish to portray, and they create the “facts” to back up the narrative. Is it what other high-profile watch brands are trying to do?
Large brands do not wish to provide honest, verifiable truth. They wish to portray an aura of invincibility and authority. The unvarnished truth has been banished. Partial truths and convenient omissions seem to be the order of the day. We all need to be on guard.
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I will return with another watch brand sleight of hand next week – they seem so prevalent now. As for SNGLRTY, well we remain as raw as it gets.