The year '71 saw the hefty performance numbers of the Road Runner begin to wane due to strict new government regulations that reined in its horsepower. The car was still available with a choice of a 383, 440 or the Hemi, but only the Hemi boasted its original horsepower. This was the last year the Hemi was available and both the 2-door pillared coupe and convertible body styles were dropped, leaving the 2-door hardtop as the only survivor. The Road Runner rightfully earned its place as one of the greatest muscle cars of the era.
1971 saw the beginning of the end of the era of muscle cars. In just its fourth year, the Road Runner saw its performance engines fall victim to tightening government regulations on emissions, fuel prices and insurance costs. The standard 383cid power plant dropped 35 hp while the 440 engines both lost 5 hp. he wheelbase of the vehicle decreased from 116 inches to 115. The 426 Hemi stayed fast at 425 hp. This would be the last year for the Hemi as it too would fall victim to the increased standards. Both the 2 Door Pillared Coupe and the Convertible body styles were dropped, leaving only the 2 Door Hardtop as the sole offering. A little over 14,000 Roadrunners were sold in 1971.