The full form of VIOC is Vertically Integrated Oil Company
VIOC stands for Valvoline Instant Oil Change, although there are plenty of other meanings as seen below.

Origin of VIOC
Valvoline as a company was founded in 1886, long before the automobile was invented. By the 21st century there were well over one thousand locations in the United States. As a company Valvoline offers fluid changes along with cleaning of integral parts of a car. They are well known for their quick oil changes, hence the name “Instant Oil Change”. When purchasing their domain name, Valvoline decided to picked “vioc” as their name thus creating the acronym.

Other Meanings
VIOC can also stand for “Vertically Integrated Oil Company” or “Verification of Initial Operating Capability”. Both uses are rarely used among the general public and even in the business sectors.

Conversation Examples
Twitter Post

“Just needed to get my car’s oil changed and the people are Valvoline were not only professional, but super fast as well. Thanks guys! #VIOC #OilChange”

Online Discussion

User 1: “Anyone know where I can go to get some cleaning done on my car?”
User 2: “A car wash?”
User 1: “I mean, not that. Like cleaning out the battery connector and any of that grime that gets up in the hood.”
User 3: “Have you tried VIOC?”
User 1: “VIOC?”
User 3: “Yeah. Valvoline. They’re cheap and efficent.”
User 2: “Oh, yeah, them. Can recommend.”