Tony Stewart Finally Opens Up About Leaving NASCAR

Knobby tires have raised tread blocks designed to bite into loose dirt or gravel. They help with traction and steering on uneven, low-grip surfaces compared with smoother tires.

Slicks are tires with little to no tread, optimized for maximum rubber-to-track contact. They’re typically used on paved or very consistent surfaces because they can’t evacuate water or dirt the way treaded tires can.

Dirt tracks are racing surfaces made of packed soil or clay, which can change grip as cars throw up ruts and debris. Tire choice is especially important because traction can vary lap to lap.

An enduro is a long-duration race where the focus is often on endurance, consistency, and strategy rather than just outright speed. In motorsports, it commonly involves running for hours and managing tires, fuel, and driver stints.

A two-stroke engine completes its power cycle in two strokes of the piston, so it tends to make power differently than a four-stroke. In racing contexts, it’s often associated with simpler mechanics and a strong, immediate throttle response—plus it typically requires oil mixing or separate oiling systems depending on the design.

“High speed” here refers to the high-speed fuel/air setting on a small racing carburetor (or carb-style fuel system). Adjusting it changes how the engine runs at wide-open throttle, affecting power, throttle response, and whether the engine runs lean or rich at speed.

A “T handle needle” is the adjustment knob connected to the needle valve in a carburetor-style fuel system. Turning it changes fuel delivery across part of the throttle range, letting the rider tune mixture and engine behavior.

Yamaha is the engine brand being referenced, and the speaker is describing how they tune it. In small racing engines (like go-karts/enduro-style setups), Yamaha powerplants are commonly carbureted and tuned with needle/mixture adjustments.

Tire prep is the set of practices used to condition race tires before (and sometimes during) a session to improve grip and consistency. It can include how tires are cleaned, warmed, and treated so the rubber reaches the right temperature and surface state for the track.

This segment contrasts older racing practices—where tires were not treated—with later approaches that used more deliberate tire conditioning. It’s essentially a discussion of how tire prep evolved and who adopted it first.

Treaded tires are tires with visible grooves and patterns designed to manage water and debris and to provide mechanical grip. In racing discussions, mentioning treaded tires usually signals a setup where traction and tire behavior are strongly influenced by tire compound and surface texture, not just slick-like grip.

The hosts reference Talladega, specifically the infield area, tying the conversation to Tony Stewart’s racing experiences at the track. This functions as a narrative anchor for the episode’s NASCAR-related reminiscing.

The Dodge Ram is a full-size pickup truck line known for towing and hauling capability, along with available high-performance powertrains. In the podcast context, it’s being promoted as a truck with very high horsepower, which is notable because it shifts the conversation from work duty to outright performance. That’s why it comes up alongside a commercial and a specific power figure.

The Ford F-150 Shelby refers to a high-performance version of the F-150 pickup developed under the Shelby performance brand. The key point here is that it’s a street-legal truck you can buy with very high advertised horsepower, which the host contrasts with what NASCAR used to run.

Horsepower is a measure of an engine’s power output—how much work it can do over time. In racing talk, higher horsepower usually means more potential acceleration and top speed, but it also changes how the car must be driven and set up.

In racing context, “Indy car” specifically means the open-wheel cars competing in IndyCar events, not just any car that happens to be in Indianapolis. These cars are engineered for high-speed stability and frequent setup changes across different track types.

The Indy 500 is a marquee American open-wheel race held at Indianapolis Motor Speedway, and it’s one of the most important events on the IndyCar calendar. Qualifying performance there is especially critical because it determines starting position for a long, high-speed race.

The USAC triple crown refers to winning three major USAC championships/series events in a single season. It’s a notable accomplishment because it requires adapting to different car types and racing formats rather than mastering just one discipline.

USAC Silver Crown refers to a championship for larger, heavier open-wheel cars that race longer distances than typical midget events. It tests endurance, strategy, and setup consistency, not just outright speed.

USAC “midget” racing uses small, lightweight open-wheel cars that emphasize quick acceleration, traction, and driver skill in tight, high-cornering-speed conditions. Winning a midget sprint championship means consistently performing at the front across a full season of short-race events.

A dirt modified is a type of race car used in dirt-track racing, typically built for durability and traction on loose surfaces. Compared with pavement racing, dirt modifieds demand different driving technique and car setup to manage slide and grip changes.

A dirt late model is a dirt-track stock-car style class known for high horsepower and close racing. “Late model” refers to the modern-era body/format rules, and competing in it usually requires mastering traction management on evolving dirt conditions.

Banking is the angled shape of a racetrack corner, where the outside edge is higher than the inside. More banking helps cars generate lateral grip and stay stable at speed, but it can also change how the car loads up as you transition through the corner.

The Toyota Supra is a performance sports coupe known for its strong acceleration and driver-focused handling. In a racing or track discussion, it often comes up because its balance of power and stability helps it stay composed through complex corners like long sweepers and elevation changes. That’s why it’s a natural reference when describing how a car behaves from turn-in to the start/finish straight.

Turbo lag is the delay between when you press the throttle and when a turbocharger can deliver boost. On track, it can make corner exits feel “dead” right when you need immediate acceleration, especially if you’re transitioning from a slow corner to a faster section.

A turbocharger uses exhaust gas to spin a turbine, which compresses incoming air to increase engine power. In racing, turbochargers let smaller engines make big power, but they introduce boost-control behavior like turbo lag and can affect how power comes on after corner exit.

“Cresting” is when the car goes over the top of a rise in the track surface. That change in elevation can alter traction and weight transfer, which affects when the driver feels grip and when the engine’s power delivery (like turbo boost) becomes noticeable.

“G’s” are a way to describe acceleration forces, measured relative to gravity (1G ≈ the force of gravity). When the speaker says “G’s in inertia,” they’re describing the lateral/turning forces you feel in a corner and how those forces affect grip and vehicle behavior.

“Cup cars” refers to the NASCAR Cup Series stock cars—purpose-built race cars based on production models. In NASCAR, the Cup rulebook and homologation shape how teams can tune aerodynamics and suspension to make the car fast and consistent.

Spring rate tuning is a core part of race-car suspension setup. Using stiffer front springs and softer rear springs changes how the car transfers load during braking and cornering, which affects grip and balance (how eager it is to turn vs. how stable it feels).

Downforce is the aerodynamic force that pushes a car downward toward the track, increasing tire grip. More downforce—especially when balanced front-to-rear—lets a race car brake harder and corner faster without losing traction.

“Nose down” describes aerodynamic and/or suspension behavior that pitches the car’s front end downward. In race setups, controlling pitch affects how the front tires load up under braking and how the car transitions into cornering.

Spring rate is how resistant a spring is to compression, and it directly influences ride height and suspension pitch under load. In a race car, the spring rate works with tires and aerodynamics to determine how the nose rises or settles after braking and during transitions.

Tire pressure sensors (often part of a tire monitoring system) alert the team when a tire’s pressure drops, which can indicate a puncture or slow leak. In racing, earlier detection helps teams decide whether to pit before the tire fails or causes instability.

A loose wheel is a serious safety issue where the wheel isn’t properly secured to the hub. It can cause vibrations, uneven tire wear, and potentially a wheel coming off, so teams treat it as urgent—especially with only a few laps remaining.

Lug nuts are the threaded fasteners that clamp a wheel to the vehicle’s hub. If they loosen, the wheel can shift or separate, which can lead to a wheel failure and loss of control.

A top fuel car is a drag-racing class that uses a purpose-built, supercharged engine and runs extremely high speeds over a very short distance. Because the car is so fast, any mechanical issue can escalate almost instantly, leaving little time to correct.

The quarter mile (1,320 feet / 402 meters) is the classic drag-racing distance. It’s short enough that cars accelerate from near standstill to extreme speeds before the driver has much time to react to problems.

Throttle refers to the driver’s control of engine power by regulating how much air/fuel the engine gets. In racing, throttle changes can sometimes help stabilize a car, but at extreme speeds the window to correct is tiny.

This segment contrasts how different racing disciplines judge driving quality. “Open wheel drivers” refers to racers in series where the wheels are exposed (not covered by a full body), such as Indy-style cars and sprint cars.

A sprint car driver competes in sprint car racing, typically short oval races with high power-to-weight cars. The episode uses this as an example of how “good driving” can mean different things across disciplines.

In drag racing, the “tree” is the signal light at the start line. Reaction time on the tree measures how quickly the driver responds to the lights, and it’s a major factor in getting off the line efficiently.

The contact patch is the portion of the tire that’s actually touching the road. If the tire spins and the contact patch is “gone,” the tire can’t generate the grip needed for acceleration, so the car loses traction.

A nitro motor refers to an engine running on nitromethane-based fuel, common in top-level drag racing. Nitro engines typically need careful throttle control because they rely on fuel flow and engine load to stay in the right operating regime.

“Short shift” means shifting gears earlier than you normally would to keep the engine in a favorable RPM/load range. In nitro drag racing, it can help maintain the engine’s required load and avoid bogging or instability when traction is poor.

“Lugging” is when an engine is forced to operate at too low an RPM for the load, so it can’t produce smooth, effective torque. The speaker notes that the situation feels like lugging, but the key is that the nitro engine still needs enough load to behave correctly.

“Free the car up” is drag-racing/track slang for reducing how tightly the car is constrained—often by changing setup or driving inputs so it can move and accelerate more freely. The speaker contrasts this with drag racing, where traction and throttle timing are more unforgiving.

The speaker is describing how, in drag racing, staying in the throttle too long can lead to a delayed fuel/combustion event. Air is compressible, so the system can “store” and then release energy/pressure differently than liquids, affecting when the engine actually gets the right mixture.

“Fuel catches up” describes a timing mismatch where the engine’s airflow/pressure and the fuel delivery don’t line up immediately. If the driver holds it too long while traction is lost, fuel can accumulate and then reach the cylinders later, leading to a delayed combustion event (“pop”).

A “drag race school” is a training program focused on learning how to run a drag car safely and consistently—things like staging, launch technique, and track procedures. The point is that drag racing isn’t only about speed; it’s also about repeating the right steps every run.

An “alcohol dragster” is a drag racing car that uses alcohol-based fuel (commonly methanol) instead of gasoline. Alcohol fuels are popular in certain drag classes because they can support high power and strong cooling effects, which helps the engine survive repeated hard runs.

A “three-speed automatic” is a transmission with three forward gears that shifts automatically rather than requiring a driver to manually select gears. In drag racing, the shift strategy matters because the car needs to stay in the engine’s power band while launching and accelerating down the track.

A burnout is when a drag racer spins the drive wheels while the car is held in place to heat the tires and improve traction. In this segment, it’s part of a pre-run routine that happens before the car goes back in to stage.

De-ice is removing frost/ice from critical surfaces so the car can run correctly. Here, the speaker describes using an alcohol spray after a burnout to dissolve frost that forms on the car’s components in cold conditions.

“Super Comp” refers to a drag racing class/ruleset where cars run specific performance and setup constraints. The speaker contrasts it with a dragster routine, implying different pre-run procedures and systems to manage.

A blower is a forced-induction supercharger that compresses air before it enters the engine, helping it make more power. In drag racing, the blower is a key system the driver/crew must manage and keep operating correctly, which is why the speaker says it was the main thing he had to “take care of.”

In racing, “doing it instinctively” means the driver has built muscle memory and learned the sequence so deeply that actions become automatic. That reduces mental load during high-stakes moments like staging, burnout, and launch.

A “nitro car” refers to a drag-racing car that uses nitromethane fuel. Nitro changes how the engine makes power and how the car is tuned, so the driving feel and setup can be very different from gasoline or alcohol-fueled cars.

An “alcohol car” is a drag-racing car that runs on alcohol-based fuel (commonly methanol). Alcohol-fueled engines have different combustion characteristics than nitro or gasoline, which affects power delivery, tuning, and how quickly a driver adapts.

A “learning curve” here means the period of repeated runs needed to adapt your driving inputs to a new car and fuel setup. Even experienced drivers often need many passes to build consistent timing, throttle control, and confidence at speed.

“80 runs” is a practical benchmark for how many drag-racing passes it can take before a driver feels truly comfortable. In high-speed racing, consistency comes from repetition—each run provides data and feedback to refine technique and car setup.

In this context, “test” refers to track sessions where drivers make multiple runs to evaluate changes and build familiarity. The speaker contrasts test-day workload (four runs) with the longer practice/competition cadence needed to get fully comfortable.

A “water box” is the staging area at a drag strip where cars are positioned over a wet section of track before making a run. The water helps cool and condition the tires so they can generate grip consistently for the first part of the pass.

“Rebuilding the motor” means taking the engine apart and replacing worn components so it can survive repeated hard runs. In motorsports testing, frequent rebuilds are common because high heat and high loads accelerate wear.

In racing, “warm up” is the process of bringing the engine, drivetrain, and tires up to operating temperature before a run. Proper warm-up improves throttle response, reduces the chance of mechanical issues, and helps tires reach the grip range they need.

Steering input is the driver’s commanded steering angle and how quickly it changes. On a “perfect run,” steering input is minimized and precisely timed to keep the car tracking straight and stable under acceleration.

“Hooked up” describes when the car has enough traction to transfer engine power to the track effectively. If the car is hooked up, the driver can apply throttle confidently; if it isn’t, the tires may spin or the car may shake, forcing the driver to adjust.

“Spins or shakes” refers to traction and stability problems during a run. Spinning usually means the tires lose grip, while shaking can indicate instability (like wheel hop or drivetrain oscillation) that ruins repeatability and can risk damage.

In racing, the “groove” is the preferred racing line/track area where tires generate the most grip. If you drift out of that line, traction drops and the car can become harder to control, especially when only one tire loses grip.

A nose wing is an aerodynamic device mounted at the front of a race car to manage airflow and generate downforce. On top fuel cars, it’s used to help keep the front end loaded so the car can respond more consistently to steering/throttle inputs.

Drag racing simulators attempt to recreate the timing, traction events, and vehicle dynamics of a straight-line run. The host suggests current simulators can’t fully reproduce the real-world physical loads (like G forces), limiting how well practice transfers.

G forces are a measure of acceleration felt by the driver, expressed in multiples of Earth’s gravity (1G). Drag racing can generate very high G loads during launch and rapid speed changes, which are difficult to replicate in simulators.

In high-speed racing, drivers sometimes have only a moment to react when the car starts to destabilize. The idea here is that if the car begins to shake or spin, you must decide immediately whether to recover or abort the run.

“Abort the run” means stopping the attempt rather than continuing when the car is unstable or the situation is unsafe. In racing, continuing through a developing spin or severe shake can damage the car or create a dangerous incident, so drivers choose to end the run early.

This describes a rapid throttle input used to regain traction and settle the car after it starts to slide. The goal is to reduce wheelspin and bring the car back to a controllable balance so the driver can get back on the throttle smoothly.

When a tire is vibrating, the vibration can show up as a certain “frequency” (how fast the tire oscillates). Changing that frequency—often by adjusting tire setup or balancing—can reduce the shaking and help the tire behave more consistently. In racing, that can matter because vibration can affect grip and tire wear.

“Cup racing” refers to NASCAR’s top-level series, where teams race for wins and points using tightly regulated stock cars. Tony Stewart’s point is that tire behavior and management are different at the Cup level than in casual go-kart racing—tires can degrade so quickly that you can’t just drive flat-out for long.

“Budget your tires” means planning how long the tires will last and how aggressively you can drive before they overheat or wear out. NASCAR teams use this to decide when to push, when to back off, and how to manage stint length so the car stays fast enough late in the run.

A restart is the restart of the race after a caution period (like after a crash or debris). Restarts are high-stakes moments because drivers and teams try to regain track position while also protecting tire condition—tires can be sensitive to how hard you accelerate and how you load them right after the field is bunched up.

The apron is the paved area next to the main racing surface (the part where cars normally run). In modern NASCAR-style racing, drivers sometimes use the apron to gain position, which changes how wide the field can run through corners and down straights.

A kick track is a rougher, often textured or lower-grip surface near the racing line designed to discourage cars from drifting off the ideal groove. If a car hits it, the reduced grip can scrub speed and help keep drivers on the intended racing surface.

A dogleg is a track section where the direction changes in a way that forces cars to turn more sharply or differently than a simple straight. On the front stretch, that kind of layout can compress the field and make lane choice more critical, increasing the chance of contact during restarts.

Tire management is how a driver controls tire wear and temperature over a stint so the tires keep producing grip lap after lap. In NASCAR, changes to tire compounds or construction can force teams to rethink driving style and car setup to keep performance consistent.

Bump stops are suspension limiters that compress when the suspension reaches the end of its travel. When a car is “riding on bump stops,” it’s effectively no longer using the spring’s normal suspension behavior—ride height and compliance are controlled by the bump stop contact, which can drastically change handling.

“Blowing tires” means a tire fails catastrophically, usually from overheating, excessive deformation, or damage, leading to sudden loss of grip. In motorsports, it’s often tied to how the tire is loaded and managed—pressure, compound, and construction all matter.

Goodyear is a tire manufacturer that supplies racing tires and can change tire construction to address issues like overheating and blowouts. In this segment, Stewart describes how Goodyear adjusted the tires’ stiffness to stop failures.

The sidewall is the flexible part of a tire between the tread and the bead. In racing, making the sidewalls stiffer changes how the tire deforms under load, which can reduce overheating and help prevent blowouts.

Stiffer sidewalls are a tire construction change that reduces tire flex. Less flex can improve stability and durability under heavy cornering loads, and it can reduce the conditions that lead to tire overheating and blowouts.

The Tesla Semi is an electric heavy-duty truck designed for long-haul freight with an emphasis on reducing emissions and operating costs. The podcast context focuses on tire choices and how tire types affect running costs, which is especially relevant for large trucks where tire wear can be a major expense. That’s why it’s discussed in terms of how fleets manage costs.

“Arrow game” is almost certainly referring to an aerodynamic “airflow” advantage—how much downforce and stability a car gains from its shape and how it interacts with the air. In stock-car racing, this often means the lead car’s clean air lets it generate more effective grip than the cars behind.

Mechanical grip is the traction a tire gets from contact with the road surface—things like tire compound, tire temperature, suspension setup, and how the car loads the tires. If rules or conditions reduce mechanical grip, drivers become more dependent on aerodynamic grip (downforce) instead.