Gull has dropped its petrol prices by two cents a litre, citing the strengthening New Zealand dollar.
A litre of regular 91 at Gull dropped to just under $1.70 at most Gull stations on Wednesday.
That is 2 cents less than at Caltex stations, and 3 cents less than at Shell.
A spokesperson for Greenstone Energy, which operates Shell, says it won't adjust its prices on Wednesday, but is monitoring the market.
