1½ ounces tequila
1 ounce lime juice
1 2-serving packet (about 1 teaspoon) sugar-free lemonade powdered drink mix
6 ounces diet lemon-lime soda
½ teaspoon Kosher salt
Combine tequila, lime juice, and powdered drink mix in a cocktail shaker. Shake to dissolve drink mix. Add soda and stir.
Rub the flesh of the lime wedge around rim of a margarita glass to moisten, and adhere the salt to the rim of the glass. Fill the glass with ice, and pour in drink. Garnish with the lime wedge.
Makes 1 serving.