Editing Triumph TR4 (section)

===Body and chassis===
The TR4's new body, produced in Triumph's Speke factory, does away with the cutaway door design and sloping boot lid of the previous TRs.<ref name="trdc-tr4"/> The taller doors allow room for wind-down windows in place of the previous side-curtains, making the TR4 a true convertible. The taller, more squared-off rear body line encloses a capacious boot for a sports car.

The car's bonnet has a power bulge or "bubble" offset to one side to clear the engine's two carburettors. Early cars have a short bubble, while cars after CT 6429 have a longer bubble.<ref name="bcf-nov2004"/><ref name="te-mar2001"/>

[[File:TR4 with surrey top.jpg|thumb|left|Hardtop with centre panel removed]]
The TR4 offered an optional hard top consisting of a fixed glass backlight with integral rollbar and a detachable centre panel made of aluminium on the first 500 units, and steel on subsequent cars. Featured on one of the ''Zoom'' prototypes, this was the first such roof system on a production car, predating the [[Porsche 911]]/[[Porsche 912|912]] [[Targa top|Targa]] by five years.<ref name="revington-zoom"/>

On the TR4 the rigid roof panel could be replaced with a vinyl insert and supporting frame. While the rigid panel could not be stowed in the car, the vinyl insert and frame could be. The factory offered the rigid top and backlight assembly as the "Hard Top kit", and the vinyl insert and frame separately as the "Surrey top".

[[File:Nottuln, Oldtimermuseum, Triumph TR4 -- 2021 -- 4516.jpg|thumb|Fascia]]
The revised interior introduced adjustable [[fascia (car)|fascia]] ventilation and a collapsible steering column.<ref name="msm-sep1961"/> Features such as these were seen as necessary to keep pace with the competition, particularly in the important US market where the majority of TR4s were sold.

The TR4 uses essentially the same ladder chassis with central cruciform bracing as the TR3. At {{cvt|88.1|in|mm|0}}, the TR4 has the same wheelbase as the earlier car, but its track widths are {{cvt|4|in|mm|0}} wider in front and {{cvt|2.5|in|mm}} wider in back than the earlier model.<ref name="trdc-tr4"/><ref name="rbros-catalogue1"/>