In this paper, a design methodology of Voltage-Controlled Oscillator (VCO) for long-range automotive RAdio Detection And Ranging (RADAR) is proposed and simulation analysis is carried out over Virtuoso SpectreRF software on Cadence tool. The frequency ranges of the mm-wave CMOS current-starved ring and LC VCOs for 45-nm CMOS technology are 24 and 76 GHz, respectively. The ring VCO at 25 GHz oscillation frequency demonstrates 2.06% tuning range, phase noise -71.61 dBc/Hz at 1-MHz offset, 3.43 mW power dissipation and layout area of 20 x 20 mm² whereas cross-coupled LC VCO achieves an oscillationfrequency of 76.25 GHz for frequency tuning range of 0.65%, a phase noise of -92.44 dBc/Hz at 1-MHz offset, 8.59 mW power dissipation and 320 x 320 mm² layout area. The proposed design of efficient VCOs shows an excellent performance for long-range automotive RADAR.