  Experiments are presented that demonstrate how liquid-infused surfaces can
reduce turbulent drag significantly in Taylor-Couette flow. The test liquid was
water, and the test surface was composed of square microscopic grooves
measuring 100 $\mu$m to 800 $\mu$m, filled with alkane liquids with viscosities
from 0.3 to 1.4 times that of water. We achieve drag reduction exceeding 35\%,
four times higher than previously reported for liquid-infused surfaces in
turbulent flow. The level of drag reduction increased with viscosity ratio,
groove width, fluid area fraction, and Reynolds number. The optimum groove
width was given by $w^+ \approx 35$.
