2024 Martinsville II Practice: What to Watch

The 2024 Martinsville II Practice is the last chance for NASCAR and Goodyear to get real-race data from their latest short-track tire. Details about the brand-new tire combo are in my last post, but to summarize:

1. Left-side tires are the softest (by 25% according to Greg Stucker) tires NASCAR’s ever run in the Cup Series. These tires haven’t been run before in competition.
2. Right-side tires are the tires that were run as the option tires at North Wilkesboro and the second Richmond race.

Crew chiefs have a scad of data already about the tires, but they will feel better when they have actual on-track data from the practice. Because of the new tires, teams have 45 minutes to practice on Saturday at 1:00 p.m. You can watch practice on the NBC Sports App.

When the cars drive off pit road, here are a few things to watch.

Pace

Pace seems to have replaced ‘speed’ lately in NASCAR. Everyone wants to know how much faster these soft tires will be?

Last year’s practice times for the fall Martinsville race ran from 20.160 seconds (Denny Hamlin) to 20.795 seconds (B.J. McLeod). It’s not a given that a softer tire produces a faster lap. Lap times depend on myriad other factors, like track temperature and how much rubber has been laid down.

But crew chiefs will be mentally correcting for the variables and comparing the raw speed in this tire to the numbers from spring, and last fall. They’ll also compare the numbers to those from their simulations, which helps determine how accurate their simulations reflect reality.

How the Track Changes

Tires impact the car, but they also alter the track. It matters whether the rubber comes off in shreds or molten layers.

If larger pieces of rubber come off the tires and cluttering up the second and third grooves, that causes problems because no driver will want to venture up in those grooves.

Even if the rubber is coating the track, too much of a coat can make the track more slippery.

It’s a beautiful morning here at Martinsville. It was about 61 F when I arrived around 8am. Unlike yesterday, the Sun is out, which means the track is already starting to collect heat.

What Tires Look Like After a Run

Most crew chiefs have become experts at identifying tires — the same way an ornithologist can identify different birds when they look identical to me. They will look at how much of the tread is worn off during a run and in what parts of the tires. They’ll also measure the temperatures to see which parts of the tires are getting hotter.

The pattern of wear gives further clues as to what’s happening on the track with the tire’s grip. The tire above shows cording on the shoulders, a clue that there’s too much wear on that part of the tire.

Lap Time Fall Off

Goodyear’s Greg Stucker told Sirius XM Radio’s The Morning Drive not to expect the tires to wear through the tread by the end of a fuel run. They expect about a second of time in 60 laps. But remember that a fast lap at Martinsville is only 20 seconds.

What you’re really interested in during the 2024 Martinsville II practice is how much time a brand-new set of tires gains per lap relative to older tires. But it’s not just their driver crew chiefs will be watching. They want to know how their competitors manage their tires. Ripping off a fast lap is one thing, but having tire left after 50 laps is when it will really make a difference.

Compare lap-time fall off of veteran drivers to those of the newer drivers and you’ll often see two different stories play out. Broadcasters have finally started reporting 10, 20 and 30-lap averages in addition to fastest practice time.

Conclusion

The 2024 Martinsville II Practice is the first — the only — opportunity for teams to learn about the new tire combination. What they learn could determine which teams move on to fight for the championship in Phoenix and which teams are bystanders.