No person shall operate any motor vehicle upon any street or alley in such manner as to permit to escape therefrom any unnecessary smoke, gas, steam, or offensive odor, or in such manner as to discharge any embers, oils, or residue from the fuel used in the operation thereof. Proof of the escape from such motor vehicle of any steam, smoke, gas, or offensive odors shall be prima facie proof that the same is unnecessary.
(Ord. 1116, passed 2-25-1957)