Measure all ingredients by eye.
Add tequila and lime juice (fresh squeezed, preferably) to a highball glass.
Add rocks and top with Topo Chico.
Garnish with a lime wheel.
Alternative preparation:
Open Topo Chico and take a swig or two
Top with tequila and squeeze of lime
Garnish with lime wedge
The official cocktail of West Texas, and the perfect end to a day in the sun.