After the generally unpopular HD Holden (1965 - 1966) the HR Holden (1966 - 1968) was designed by General Motors U.S. to be more popular with the Australian public, this was well accepted with the sales of the HR being at 252,352 compated to the HD at 178,927, which bought sales of the HR Holden back to the level that Holden received from then popular EH Holden which had sold 256,959 vehicles.
Changes to the HR over the HD appeared superficial but included: Vertical split tail lights (altered from the HD wrap around tail lights), Sharper nose, less pinched panels (which has resulted in a general consensus that they have weathered the years better against rust), the raised ends on the front bumper were removed, the indicator lights were removed from below the front bumper and integrated into the grille, slightly widened track. Optional extras included front wheel disc brakes, power steering and a limited slip differential.
Engine capacity was also increased over the HD motors, the 149 which was used in both the EH and HD was enlarged to become the 161. The 179 was also enlarged to become the very popular 186. The performance motor or X2 that was popular on the HD (recogniseable by its twin carburettors and X2 badging) became more powerful in the HR with increased size and now had around 145 horsepower. Six months into production the HR was given a safety upgrade which included front seat belts, windscreen washers, reversing lights, sunvisors, and shatterproof interior rear-vision mirror.
In June 1967 the X2 was finally replaced by the hugely popular 186S which continued through into the later model monaros as a viable alternative to the V8 engines. The 186S had the same power as the X2 but used a single (double barrel) carburettor compared to the twin carburettor X2, this allowed for easier more reliable tuning and running, it also included Holdens first automatic choke.
Another new addition for the HR was the option of a 4-speed floor shift manual (as opposed to the still available 3-speed column manual and 2-speed powerglide automatic). The 4-speed was found however to be unreliable and too weak for the 6 cylinder Holden motors (it was an Opel box designed for smaller motors) and was refined in later models.
The HR Holden was released in the now standard types of Standard, Special, Premier and Commercial (Ute and Panel Van).
Standard - The Standard HR was easily recogniseable by it's single body colour and lack of exterior trim and badges.
Special - The Special was the most common type of HR, it included more exterior colours, an optional white roof, extra stainless steel decorative strips and exterior badging ("Special")
Premier - The Premier was the top of the line. It included wood trimming (artificial) in a panel along the top of the door trims, console, dash and horn button. It included a vinyl roof as an option and Premier trim included stainless steel around the wheel arches (no side strips), along the boot between the tail lights, longer dog leg stone guards (below the rear wheel arch chrome trim). The circular park/indicator lights in the grille (parkers went off as the headlights went on, a Holden trait until the HT) had white painted accents around their rims.
The HR Holden was the last of Holden's range to not have an option of a V8 motor, having said that though it was also a very important model due to improvements in safety, braking, handling and steering over its predecessors.