Upon starting operations at his new factory in Molsheim, Bugatti refined his light shaft-driven car into the Type 13 racer. This included boring the engine out to 65 mm for a total of 1.4 L (1368 cc/83 in3). A major advance was the four-valve head Bugatti designed — one of the first of its type ever conceived. Power output with dual Zenith carburetters reached 30 hp (22 kW) at 4500 rpm, more than adequate for the 660-lb (300-kg) car. Leaf springs were now fitted all around, and the car rode on a roughly 2-m (79-in) wheelbase.

Although having the appearance of a toy, the Bugatti Type 13 was successfully raced. It was seen at hillclimbs as early as 1910 looking rather out of place compared to the bulky and brutish competition. What the Type 13 lacked in power, it made up in handling, steering, and braking. These important elements were retained throughout all future Bugatti designs. Top speed was at 125 km/h.

The new company produced five examples in 1910, and entered the French Grand Prix at Le Mans in 1911. The tiny Bugatti looked out of place at the race, but calmly took second place after seven hours of racing.

World War I caused production to halt. Ettore took two completed Type 13 cars with him to Milan, Italy for the duration of the war, leaving the parts for three more buried near the factory. After the war, Bugatti returned, unearthed the parts, and prepared five Type 13s for racing.

A Grand Prix for Voiturettes at Le Mans was the only French event of 1920, and Bugatti entered the two completed cars from Milan and one more from the remaining parts. Ettore’s illegal act of placing a hand on the radiator cap to tighten it on De Vizcaya’s car during a brief stop near the end of the race when he was running in second place brought disqualification to the leading car.  According to the rules of the race, no one but the driver was allowed to touch the car.  The crowds were highly displeased with this decision but Ettore accepted the harsh blow without comment.  Ernest Friedrich, another Bugatti driver, who was running in third place at the time of the disqualification, was able to catch and pass Braccoli, the leader, near the races end and take first place. 

1921 would be the year that really launched Bugatti onto the world stage and limelight.  Five Model 13’s were entered by Bugatti into the Italian Brescia Grand Prix that year.  The diminutive Type 13 proved unbeatable compared to their much larger competitors. A theory generally accepted at the time was that the heavier the weight, the better the car would hold the road at speed.  Ettore Bugatti believed that the exact opposite was true whereby light cars with high power and a properly designed chassis and suspension would be superior.  The Model 13 would prove him resoundingly right when Bugatti’s cars finished in the top four places giving them the attention of race car fans and drivers across the world. 

Capitalizing on this victory, all subsequent four-valve Bugatti models bore the Brescia moniker in remembrance of the sweeping victory at the Brescia Grand Prix.  Orders began pouring in from around the world, and Bugatti would become one of the most recognized and distinguished car manufacturers in the world.