On some occasions, Peloursin and Syrah vines may be called Petite Sirah, usually because the varieties are extremely difficult to distinguish in old age.

In the 1860s the French botanist François Durif kept a nursery of several grape varieties at his home in the commune of Tullins where he most likely had plantings of both Peloursin and Syrah.

[2] As a conclusion of DNA fingerprinting at the University of California, Davis in 1997, Syrah was identified as the source of the pollen that originally crossed with Peloursin flowers.

[6] Confirmed as recently as 2024, old plantings of Durif continued to be used to produce popular wine in the Rutherglen, Victoria region of Australia.

[5] In years when heavy rain or the excess sun has weakened the quality or yield of Cabernet Sauvignon or Pinot noir plantings, Petite Sirah may also be used as a blending partner to strengthen the wine.

The UC Davis-trained winemaker and Ph.D. chemist Ya'ir Margalit, familiar with the grape from his time in California, showed that Petite Sirah need not be consigned to jug wine when he blended small portions into his reserve Cabernet Sauvignon.

[16] In the 20th century, ampelographers Louis Levadoux and (decades later) Linda Bisson categorized Durif as a member of the Pelorsien eco-geogroup along with Bia blanc, Béclan, Dureza, Exbrayat, Jacquère, Joubertin, Mondeuse blanche, Peloursin, Servanin and Verdesse.

[14] Petite Sirah can sometimes be rather "short", that is, the flavor does not linger in the mouth, hence the benefit of blending with another grape which may lack mid-palate depth, but adds length and elegance.