Elgin-based Gleaner, which operates the UK's most northerly 24-hour filling station 14 miles north of Inverness, has reported pre-tax profits of £889,351 for the year ended December 31.
Earnings were more than four times higher than the £214,891 booked in 2011, as turnover surged to £126.6m from £122.5m.
The company, whose interests include a boiler maintenance division, benefited from 2012 being 7.8% colder than 2011, with the lower temperatures bringing increased sales in the heating market for both oil and gas products.
Gleaner, whose shareholders have announced plans to sell the business to retire, also said increased production in the whisky industry had brought a spin-off to fuel oil sales.
However, the directors, writing in accounts newly available at Companies House, said its forecourts, based largely in rural areas, had performed less well as supermarkets continue to move into smaller communities, towns and villages.
The directors added: "There are still filling stations closing and this is a concern. What was pleasing to our company was that almost 50% of our rural sites had modest increases."
Gleaner called for financial help to allow rural filling stations to upgrade or replace ageing pumps, tanks and other equipment, and for regulations to be eased.