According the to Automotive Aftermarket Industry Association (AAIA), the Do-it-Yourself (DIY) segment of the automotive aftermarket is not shrinking. In fact, the percentage of DIYer households in the United States has remained constant for the past six years.

"The Aftermarket Consumer: Do-it-Yourself or Do-it-For-Me" study reveals that since the last study in 1994, the percentage of U.S. households performing light, medium or heavy-duty DIY maintenance has not changed. Nearly half of all U.S. households contain at least one automotive DIYer despite a sharp decline in the 25 to 44-year-old "prime" DIY age group.

"Although the portion of DIYers has not changed since we did this study in 1994, the frequency with which DIYers work on the vehicles has declined," said Alfred L. Gaspar, AAIA president and CEO. "Our research shows that a higher percentage of DIYers have gone from doing maintenance monthly or once every two to three months to less than once every two to three months."

A significant drop of 26.6 percent in DIY oil changes occurred in the past six years. For example, 75 percent of DIYers changed their own oil in 1994. In 2000, the percentage dropped to 55 percent.

The AAIA study provides a number of DIY and DIFM profiles by age, gender and light, medium and heavy DIY level. The typical light DIYer is 49 years old, male or female (male 51%, female 49%), married, with a college education, $57,700 household income, with two vehicles, who works on his/her vehicle an average of 12 times a year primarily to save money. Whereas, the typical medium and heavy duty DIYer is a married male who works on his vehicle 16 and 20 times a year, respectively.

The DIFM section of the study shows that two-thirds of DIFMers choose aftermarket service facilities over new car dealerships, listing trust, convenience, guarantee and cost as the rationale.