In the aftermath of victory by Ray Harroun in the single-seat Marmon "Wasp" in the first 500-Mile Race the year before, new rules make the presence of riding mechanics mandatory; maximum engine size remains 600 cubic inches (9.83 liters) displacement. At $50,000, the race purse is nearly double that of 1911.
Out of 29 original entries, 24 qualify for the race by sustaining a speed faster than a minimum of 75 mph (120.7 km/h) for a full lap, an increase from the quarter-mile qualifying distance of the inaugural year. David L. Bruce-Brown runs fastest at 88.45 mph (142.35 km/h), but starting positions are again determined by entry date. Lining up five cars to the first four rows and four to a fifth, a change from the previous year's starting method is movement of the pace car, a Stutz, from the inside of the first row to out in front of the field.
Upon wave of the then-red starting flag, Teddy Tetzlaff takes the lead in a Fiat from the third starting position in the center of the first row, and leads for the first two laps before being overtaken by the grey # 4 Mercedes of Italian-born Ralph DePalma.
DePalma's domination of most of the event is total, as he builds an eventual five-and-a-half lap, eleven minute advantage over second, and leads uncontested for the next 194 laps...before suffering one of the most confounding mechanical failures in motorsport history at the beginning of lap 197, as his Mercedes begins misfiring, and slowing on the mainstretch at the conclusion of the lap. Nursed on the 198th lap by DePalma at reduced speed, the car finally loses all power at the end of the backstretch on lap 199, as a broken connecting rod rips a hole in the crankcase.
With the car's momentum carrying it around to the fourth turn, DePalma and riding mechanic Rupert Jeffkins then enter themselves into motor racing lore, as well as inspire the cheers of the more than 80,000 in attendance, as they climb from the vehicle and begin pushing it down the five-eighths of a mile mainstretch toward the start-finish line.
Indianapolis driver Joe Dawson, running in the second position for most of the race in his blue and white National Motor Vehicle Company entry, finally passes DePalma midway down the mainstretch to assume the lead for the concluding two laps, the fewest led to date in either a single race or an entire career by a race winner, following DePalma's 196 laps in the lead being the most ever in a race by a non-winner. Finishing more than ten minutes ahead of newly-second place Tetzlaff, Dawson completes another two laps for good measure upon fear of a scoring miscue. Sometime thereafter, DePalma and Jeffkins finally bring their car across the line, but in twofold futile endeavour: Speedway rules, requiring that all entries move under their own power, mark DePalma's final number of circuits at 198, and the push across the line, even if to be counted, bringing them only to the beginning of the final lap.
Dawson's run in the American-manufactured, four-cylinder National, with a winning time of 6:21:06 and averaging 78.719 mph (126.686 km/h), is twenty-one minutes two seconds faster than the previous 1911 record; he garners $20,000 and additional contingency awards.
Throughout the remainder of the field, only the top ten finishers earn prize money, rules stipulating all entries complete the 500 miles to collect. Ralph Mulford, involved in the controversial finish the year before, and being forced to stop numerous times due to clutch problems in his Knox, finds irritation with the requirement and proceeds to drive on, long after all others are presented the chequered flag...and even after Speedway president Carl Fisher and starter Fred Wagner leave the grounds (the latter after getting into an argument over whether to flag Mulford off before he had completed the distance, Wagner in favor and Fisher against).
Through numerous accounts of the run, including his reportedly changing shock absorbers for a gentler ride, as well as stopping for a dinner-on-the-go of fried chicken and ice-cream with his riding mechanic, Mulford's finish finally arrives, amid deserted grandstands and a setting sun over the mainstraightaway, 8:53:00 after the start, and with an average speed of 56.285 mph (90.582 km/h), which remains a record: the slowest finishing speed to date in 500 history.
|Driver||Far Inside||Inside Center||Center||Outside Center||Far Outside|
|Row 1||Gil Andersen||Len Zengel||Teddy Tetzlaff||† Ralph DePalma||Eddie Hearne|
|Row 2||Spencer Wishart||Joe Dawson||Howdy Wilcox||Harry Knight||Bert Dingley|
|Row 3|| Johnny Jenkins|| Bob Burman|| Eddie Rickenbacker|
Qualified by Lee Frayer
| Billy Liesaw|| Bill Endicott|
|Row 4||Ralph Mulford||Hughie Hughes||Joe Horan||Mel Marquette||Len Ormsby|
|Row 5||Joe Matson||Charlie Merz||David L. Bruce-Brown||Louis Disbrow|
|1||8||Joe Dawson*||National||National Motor Vehicle Company||National||National||4||491|
|blue / white||86.13|
|2||3||Teddy Tetzlaff||Fiat||E. E. Hewlett||Fiat||Fiat||4||589|
|3||21||Hughie Hughes||Mercer||Mercer Motors Company||Mercer||Mercer||4||301|
|4||28||Charlie Merz||Stutz||Ideal Motor Car Company||Stutz||Wisconsin||4||390|
|5||18||Bill Endicott||Schacht||Schacht Motor Car Company||Schacht||Wisconsin||4||390|
|6||2||Len Zengel||Stutz||Ideal Motor Car Company||Stutz||Wisconsin||4||390|
|7||14||Johnny Jenkins||White||White Indianapolis Company||White||White||6||490|
|8||22||Joe Horan||Lozier||Dr. W. H. Chambers||Lozier||Lozier||4||545|
|white / red||80.48|
|9||9||Howdy Wilcox||National||National Motor Vehicle Company||National||National||4||590|
|blue / white||87.20|
|10||19||Ralph Mulford||Knox||Ralph Mulford||Knox||Knox||6||597|
|white / red||87.88|
|11||4||† Ralph DePalma||Mercedes||E. J. Schroeder||Mercedes||Mercedes||4||583|
|5||4||196||198||did not finish||connecting rod||0|
|12||15||Bob Burman||Cutting||Clark-Carter Auto Company||Cutting||Cutting||4||598|
|white / red||84.11|
|7||12||0||157||did not finish||accident,|
|13||12||Bert Dingley||Simplex||Bert Dingley||Simplex||Simplex||4||597|
|red / white||80.77|
|14||10||0||116||did not finish||connecting rod||0|
|14||25||Joe Matson||Lozier||O. Applegate||Lozier||Lozier||4||545|
|white / red||79.90|
|17||21||0||110||did not finish||crackshaft||0|
|15||7||Spencer Wishart||Mercedes||Spencer Wishart||Mercedes||Mercedes||4||583|
|gray / black / red||83.95|
|9||6||0||82||did not finish||water connection||0|
|16||3||Gil Andersen||Stutz||Ideal Motor Car Company||Stutz||Wisconsin||4||390|
|gray / white||80.93|
|12||1||0||80||did not finish||accident,|
|17||17||Billy Liesaw||Marquette-Buick||Will Thomson||Marquette||Buick||4||594|
|tan / red||77.51|
|21||14||0||72||did not finish||caught fire||0|
|18||46||Louis Disbrow||Case||J. I. Case T. M. Company||Case||Case||6||450|
|white / red||76.54|
|23||24||0||67||did not finish||differential pin||0|
|19||23||Mel Marquette||McFarlan||Speed Motors Company||McFarlan||McFarlan||6||425|
|20||19||0||63||did not finish||broken wheels||0|
|20||6||Eddie Hearne||Case||J. I. Case T. M. Company||Case||Case||6||450|
|white / red||81.85|
|10||5||0||55||did not finish||burned bearing||0|
|21||16||Eddie Rickenbacker||Firestone-Columbus||Columbus Buggy Company||Fiat||Firestone-Columbus||4||345|
|crimson / black||77.30|
|22||13||0||43||did not finish||intake valve||0|
|22||29||David L. Bruce-Brown||National||National Motor Vehicle Company||National||National||4||590|
|blue / white||88.45|
|1||23||0||25||did not finish||valve trouble||0|
|23||10||Harry Knight||Lexington||Lexington Motor Car Company||Lexington||Lexington||6||422|
|brown / white||75.92|
|24||9||0||6||did not finish||engine trouble||0|
|24||26||Len Ormsby||Opel||I. C. Stern & B. C. Noble||Opel||Opel||4||450|
|gray / red||84.09|
|8||20||0||5||did not finish||connecting rod||0|
Race field average qualifying speed:
Finishing entries average time and finishing speed: