Toe

Toe is the angle the front tires point in or out relative to the car's centerline, viewed from above. Toe-in means the leading edges point toward each other; toe-out means they point apart.

Also called:

toe-in, toe-out

In practice

Circle-track racers usually talk about toe in fractions of an inch — the difference between the front and rear of the two tires, measured at hub height with a toe plate or tape. Common adjustments land around 1/16 to 1/8 inch. Direction depends on the car and the racetrack: iRacing’s circle-track guide puts toe-in on “lightweight cars that don’t have a lot of shifting weight” and tight corners, and toe-out on “heavier cars that have a lot of load transfer” and long sweeping tracks. Toe-in adds straight-line calm at the cost of scrub; toe-out sharpens turn-in and gets darty. RC cars use the same idea, set with turnbuckles and usually stated in degrees.

Why it matters

Toe is the cheapest alignment change you can make and one of the easiest to leave wrong after contact, because a tweaked tie rod hides in plain sight.

Go deeper

Read the full post:

Camber, Caster & Toe Explained for RC Racers

Sources

Circle-Track Setup: What Is Toe, And Why Should You Use It? — iRacing — circle-track setup article on toe-in vs. toe-out and which cars and corner shapes want each.
Better Performance with Proper Front End Alignment — Circle Track Warehouse — racing distributor’s alignment guide defining toe from above and expressing it in inches.