What is an advantage of a 5/8-wavelength whip antenna for VHF or UHF mobile service compared to a 1/4-wave antenna?

A 5/8-wavelength antenna physically concentrates more of its radiated signal toward the horizon compared to a standard 1/4-wavelength whip. By focusing the radio frequency energy outward where it is most useful for terrestrial VHF and UHF communications, the antenna effectively increases the signal strength in that direction. This directional concentration of energy is known as antenna gain. While a 1/4-wave antenna radiates effectively, a 5/8-wave antenna provides more gain, making your signal sound stronger to distant stations. It is incorrect to say it radiates at a higher angle, as a higher angle would actually send your signal uselessly up into space rather than out to other terrestrial stations.