New Delhi, May 15: Petrol and diesel prices were increased on Friday by Rs 3 per litre after state-owned oil firms ended a four-year record hiatus in rate revision. Petrol price was hiked to Rs 97.77 per litre from Rs 94.77 in the national capital. Diesel now costs Rs 90.67 as against Rs 89.67 per litre previously, according to industry sources.