Note: This piece was originally published on my Substack as part of an earlier rollout. I’m archiving it here on Beehiiv for accessibility and continuity. Minor edits may have been made for formatting.
The Belgian Grand Prix is delayed due to heavy rain. If only there were a kind of tire that could be used in wet weather… (F1 Twitter)
I was excited to write the Belgian Grand Prix edition of Lazy Thoughts. And how couldn’t I? Qualifying Saturday was a treat—McLaren secured its fifth 1-2 lockout this season, Charles Leclerc and Max Verstappen were steadily behind them, and Yuki Tsunoda finally got his flowers by qualifying in P7. The grid looked charged and ready for what could have been an exciting start to the second half of the season.
But then, the weather happened.
Rain hit Spa like it tends to do, soaking the track and washing away Sunday’s hopes for a good race. Racers were lapping behind the safety car within minutes. Before the lights could go out, race control waved the red flag. The Grand Prix was officially delayed.
Every time a rain delay happens in Formula 1, my social media feed is inundated with questions and memes about the wet tires— the ones made specifically for stormy weather. Blue sidewall, deep grooves, engineered to part seas like Moses with a downforce package. And yet, they seldom show up much to the bemusement of race fans:
“Why don’t they just use the wets?”
“Isn’t that what the wets are for?”
“Why even make wet tires if they’re not going to race?”
One meme about the wet tires posted during the Belgian GP delay
I got curious, too. Why don’t racers use the wet tires? Aren’t they supposed to be used in heavy rain? Isn’t that the whole point?
So in the delay, I did what any fan with too much time on their hands would do: I went digging for answers.
And boy, did I find them.
A Brief History of the Wet Tires
The two tires for wet weather: wets (left) and inters (right) (Pirelli’s website)
The current era of F1 wet-weather tires began in 2012 when Pirelli introduced its Cinturato sub-brand for intermediate and full-rain compounds. This as the company’s slicks stayed under the P Zero label, splitting their tire offerings into two.
This wasn’t just a marketing gimmick. Rather, Pirelli wanted rain tires that were stronger, grippier, and more visually distinct than their predecessors. Why? To support new regulations for cars and to allow race strategy to be more dynamic.
The intermediate tires didn’t change much— they simply got a green coat of paint and had the Cinturato label slapped on. The full wets, though, got a makeover. Their grooves were deepened to maximize water evacuation. Their diameter increased to avoid aquaplaning. They were designed to bring the most out of an F1 car in the worst possible weather.
Contrary to what you may think, wet tires have been used before in F1 races. In 2014, all the racers started on full wets for the infamous Japanese Grand Prix due to Typhoon Phanfone. The same happened amidst heavy rain during the 2016 Monaco Grand Prix. And during the 2017 Singapore Grand Prix.
But here’s the catch: none of these were full-race showcases for full wets. They were red-flagged or safety car-staggered. The drivers quickly shifted to other tires once the track dried up. In other words, the full wets made an appearance, but not an impact.
So what’s stopping teams from actually using them in real racing?
That’s where the FIA’s own rules come in.
The Rules Surrounding Wet Weather Racing
The 2025 Belgian Grand Prix began with a safety car lead in the pit lane, following a long rain delay (F1 Twitter)
According to the 2025 F1 sporting regulations published by the FIA, each driver is allocated four sets of inters and three sets of wet tires per race. If a track is deemed to be affected by rainy weather, excessive water, or some other kind of excessive moisture… the race director can officially declare it a “wet track”. At that point, drivers are allowed to use wet-weather tires. If a race starts behind the safety car due to weather, much like how it did at Spa this year, those tires become mandatory.
You might be thinking, “Okay, then why don’t drivers use the wets when they’re mandatory?”. Take another look. The rules mandate “wet-weather tires” under stormy conditions. That doesn’t exclusively mean the full wets.
“Wet-weather tires” refer to both the full wets and the inters. And in most cases, the latter is the default. Why? Because inters do just enough in wet weather without sacrificing performance. They’re more versatile, more forgiving, and less likely to turn your car into a sauna on wheels the moment the track dries up.
The full wet tires are made from a soft rubber, packing heat-sensitive oils and plasticizers into its groovy surface. A dry track turns that softness from a perk to a liability. They overheat fast. Like, ridiculously fast. So fast that even Pirelli’s head of motorsport acknowledged it as an issue in a recent interview:
“You put more and more grooves into the [full wet] tyres. But that means you have smaller tread blocks and that those blocks will move more. If those blocks move, you generate heat and that means that we had overheating of the wet tyre. It seems a joke, but it's true!”
And what happens when those tires overheat? They melt. They lose grip. The car slides more, brakes worse, and loses precision in the corners. An absolute nightmare for anyone hoping to score points during a race.
Inters, on the other hand, have shallower grooves. While they move less water per second when compared to a full wet, they still do enough to keep in contact with the track. They’re perfect for racing in light rain, standing water, and everything in between. When the track dries up, the inters don’t immediately lose grip or blister into oblivion. They buy drivers just enough time to make a pit stop and switch to slicks.
Inters also kick up less spray from a wet track, which is important… but often overlooked.
Because here’s the thing: spray, not grip, is what kills wet-weather racing.
Hey Who Sprays It, Delays It
Spray is a problem during wet-weather racing, as seen here at the 2025 British GP (F1 Twitter)
The real villain of wet-weather racing is spray. It’s not dramatic like a crash or tweetable like cussing out the team on radio, but it is why the grid crawls behind a safety car when the skies start crying.
In basic terms, spray is the cloud of atomized water kicked up by the tires and expelled by an F1 car’s underbody. It’s a dense, lingering fog that clings to the air— especially problematic if you’re going hundreds of kilometers an hour in a high-stakes Grand Prix.
Several drivers have spoken out about how difficult it is to drive in the spray. McLaren’s Lando Norris saying visibility in heavy spray was “terrible” during Spa. Mercedes’ George Russell describing spray as something where “you literally cannot see anything, you may as well have a blindfold on.” Aston Martin’s Lance Stroll calling it “a huge safety issue” in 2023, urging the FIA to address it.
And on a personal level, I see what they mean. I was caught in a heavy rainstorm just last week, driving home after visiting family two hours away. It was one of those “two-minute” torrential downpours common in the Gulf Coast during the summer, the kind that makes it look like you’re underwater. I slowed to a crawl. I gripped my steering wheel with both hands. But even then, I couldn’t see the taillights of the cars in front of me. They were just blinking red dots in a blurry gray void.
Now multiply that by ten, make it faster, and put it on live television. That’s what the drivers are facing when they race in heavy rain.
So when a race gets delayed due to the rain, this is what the real concern likely is. It’s not because the rain is too much, but because the spray could be too thick to see out of. It’s not the water on the ground; it’s the water that goes up in the air. It’s the very thing that makes modern F1’s speed and aerodynamics a double-edged sword.
And ironically, that’s why we rarely see the wet tires in action. When the spray is at its worst, racing is no longer possible— regardless of how capable the tires are.
Why Do the Wet Tires Still Exist?
A bunch of wet tires that were likely never used (F1 Fansite)
So why does Pirelli make wets at all if they’re never used? The basic answer: They have to.
As I said earlier, FIA rules mandate that each driver is given four sets of inters and three sets of wet tires per race. That’s seven full sets of rain-ready rubber per weekend, whether it’s needed or not. And it all but guarantees the full wets are never used.
But there might be a happy ending on the horizon for those tires. Pirelli is actively working on its next generation of inters and full wets. The goal? To make full wet tires that are not just safe, but usable. Wets that don’t overheat on a drying track. Wets that can actually race.
It tested the tires back in June with Ferrari, with two days of on-track sessions at Fiorano. The lab testing was even more aggressive, with over 1500 kilometers of indoor simulations— hammering the tires under controlled rain conditions, variable heat, and simulated track drying.
The hope is that by 2026, when Formula 1’s next big regulation overhaul drops, the new wets will be ready to be a true racing tire. Not a tire that checks a box and gets parked after lap one. One that can compete.
It’s an ambitious target. But if it works, the full wets might just not be the butt of every rain delay joke anymore.
Until next time,
F