What size engine is in a 1966 Dodge Coronet?
In 1966, the Dodge Coronet offered multiple engine sizes, from a 3.7-liter slant-6 up to a 7.0-liter 426 Hemi, with several V8 options in between (273, 318 and 383).
Engine options for the 1966 Coronet
The following powerplants were available to buyers depending on trim level and options in the 1966 Coronet lineup.
- 225 cu in (3.7 L) Slant-6
- 273 cu in (4.5 L) V8
- 318 cu in (5.2 L) V8
- 383 cu in (6.3 L) V8
- 426 cu in (7.0 L) Hemi — optional on high-performance models such as the R/T
Note: Engine availability varied by trim and production date; not every engine was offered on every Coronet body style or option package.
Performance snapshot by engine
Here is a general sense of the power associated with those engines, acknowledging that output varied with carburetion, compression, and tuning.
- 225 Slant-6: around 145 hp (SAE gross)
- 273 V8: around 180 hp
- 318 V8: around 230 hp
- 383 V8: roughly 280–330 hp depending on configuration
- 426 Hemi: about 425 hp (SAE gross) in 1966
Factory ratings from the era varied by test conditions and options, so real-world output could differ by car.
Trim and model alignment
Within the Coronet line, the high-performance R/T (Road/Track) usually carried the top engine options — most notably the 426 Hemi — while other trims could be paired with the smaller V8s or the slant-6.
Summary
The 1966 Dodge Coronet could be equipped with a range of engines from a modest slant-6 to a legendary 426 Hemi, reflecting Mopar’s approach to offer both economical and high-performance configurations within the same model line. Buyers could choose from several V8 options (273, 318, 383) in addition to the base slant-6, with the 426 Hemi reserved for the sportier R/T and related packages.
