FuelFacts

Does the 1984 Mercury Marquis need premium gas?

Every trim takes regular — no premium needed.

Trim (engine / transmission)FuelMPGFuel/yr
2.3L 4-cyl, Automatic 3-spdREGULAR20$3,100
3.8L 6-cyl, Automatic 4-spdREGULAR19$3,300
2.3L 4-cyl, Automatic 3-spdREGULAR19$3,300
3.8L 6-cyl, Automatic 4-spdREGULAR19$3,300
3.8L 6-cyl, Automatic 3-spdREGULAR18$3,450
3.8L 6-cyl, Automatic 3-spdREGULAR18$3,450
3.8L 6-cyl, Automatic 3-spdREGULAR17$3,650
5.0L 8-cyl, Automatic 4-spdREGULAR17$3,650
5.0L 8-cyl, Automatic 4-spdREGULAR16$3,900
The EPA records the fuel each version was tested on. Whether premium is strictly required or just recommended is an owner's-manual detail the EPA dataset doesn't include — so we don't guess it.

9 trim(s) · EPA FuelEconomy.gov · retrieved 2026-06-14.