This project aimed to assess the effect of tap diameter reduction (19/64 in. vs. 1/4 in.) and lateral tubing diameter reduction (5/16 in. vs. 3/16 in.) on the volume of sap collected under high vacuum (28 po Hg) in 2 Centre ACER sugar bushes during the 2015 season. The results obtained showed a decrease in collected sap volume for systems having 1/4 in. diameter taps compared to those with 19/64 in. diameter taps in both sugar bushes studied. The mean decrease is 11.5% for the 2 sugar bushes, which is inferior in proportion to the reduction of the tap’s dimension (16% for diameter and 29% for volume). The use of a reduced-diameter sap spile may thus apply to deficient sugar bushes in terms of vigor and radial tree growth and for which a reduction of the internal compartmentalization of the tree associated with tapping would be desirable without penalizing the volume of collected sap too much. Results furthermore show that the smaller-diameter tubing (3/16 in.) also offered a decrease in sap collected compared to the 5/16 in. diameter tubing. On the other hand, this decrease (11%) was only observed in one of the two sugar bushes having a weak grade and a high sap run rate. According to the results, there is no advantage in using an inferior-diameter lateral tubing operated under high vacuum in a sugar bush having a high sap run rate and a low grade. In these conditions, the lower-diameter tubing appears unable to adequately evacuate the sap, thus resulting in a loss of volume at season’s end (in French only).