Is wudu valid if only its obligatory acts are performed?

It is sufficient for a Muslim to fulfill the obligatory (fard) and necessary (wajib) acts of any act of worship in order to be absolved of their religious responsibility. Therefore, performing the obligatory acts of wudu is enough for its validity. However, the sunnah acts complete any deficiencies that may occur in the obligatory acts and also increase the reward gained. For this reason, deliberately omitting the sunnah acts while performing wudu is considered disliked (makruh). (Ibn Abidin, Radd al-Muhtar, 1/103-104)

Source: T.C. Diyanet İşleri Başkanlığı, Din İşleri Yüksek Kurulu