Get a PowerTap wheel set and apply it to a structured training program. An extra 50 Watts will do far more for your speed than $2000 carbon fiber wheels.

At common apparent wind yaw angles better wheels usually save under 1.5W at 20 MPH and 4W at 30, with the difference increasing to 3.5W and 12W respectively using bad contemporary alloy wheels in atypical crosswinds.

500g lighter wheels save a 70kg rider on a 9kg bicycle just 25 seconds an hour climbing in the mountains - 0.7% faster, which is a 1.75 W savings for that rider producing 250 W.

If that 500 g was where the rubber meets the road it would count double accelerating for up to 1.3% of total kinetic energy. However, accelerating that rotating weight from 0–20 MPH takes only 2 (kinetic energy rotating + in a straight line) * 0.5 kg * (8.9 m/s)^2 / 1000 kj / j = 0.079 kj which is what you spend covering 12 feet at 20 MPH requiring 35 kj / mile.

https://www.quora.com/Are-wheels-the.../Drew-Eckhardt

Stress relieve your wheels, insure they have adequate uniform tension, and you'll be fine until you bend the rims on a road obstacle or crash them.