The popular Triumph Dolomite small car was produced by the British Leyland Corporation's Triumph Motor Company division in Canley, Coventry, between October 1972 and August 1980.

Dolomite was the final addition to the Triumph range of small cars (codenamed "Project Ajax"), which started in 1965 with the Triumph 1300. Designed to be a replacement for the rear-wheel drive Triumph Herald,  the 1300 was originally equipped with a 1,296 cc (79 in) engine and front wheel drive. The later model, introduced in September 1970 as the Triumph 1500, featured a remodeled front and rear, styled by Michelotti, and a larger 1,493 cc (91 cubic foot) engine.

Triumph was, however, dissatisfied with the performance of the 1300 market; although it was moderately successful, the higher price and greater complexity meant that sales never reached the levels of the simplest and cheapest Herald that preceded it. In an attempt to improve things, the car was extensively redesigned. Launched in September 1970, the Triumph Toledo was a cheaper and basic version of the 1300, but with conventional rear-wheel drive. This new model was assembled alongside the front-wheel drive version now of larger engines (the Triumph 1500) which was launched at the same time as the Toledo.

Although Dolomite was refined and fast, competitors like BMW 2002 had a performance advantage that cost Triumph dearly, both in terms of sales and prestige. To remedy this, Triumph launched the Dolomite Sprint in June 1973, although the launch was delayed for a year; should be on sale in 1972.

A team of engineers led by Spen King developed a 16-valve cylinder head with all valves being driven using a single camshaft instead of the more conventional DOHC arrangement. Capacity has also been increased to 1,998 cc (122 cubic feet) and, combined with larger carburetors, production has been increased to 165 Nm (4.5 lbf) and 127hp (95 kW) at 5,700 rpm. This represented a significant increase in power over the smaller 1850cc variant, however, it fell short of the original goal of 135 hp (101 kW).



Although BL engineers were able to extract a reliable 150 bhp (112 kW) from the test engines, the production line was unable to build the engines to the same level of quality, producing 125 bhp (93 kW) at 130 cv (97 kW). This led to the designation of the original model, the Dolomite 135, to be replaced in the short term by the name of Sprint.

As a result of using this engine, the Dolomite Sprint was claimed to be "the first mass-produced multivalve car". While other multivalve engines (especially the Lotus 907) were produced in volume, they were not used in mass production vehicles until after the introduction of the Dolomite Sprint. The cylinder head design won a British Design Council award in 1974. Performance was excellent, with 0–60 mph taking about 8.4 seconds, with a top speed of 119 mph (192 km / h). Trim was similar to that of 1850, with the addition of standard alloy wheels (another first for a British production car), a vinyl roof, front spoiler, twin exhaust and lowered suspension. The seats were now made of cloth in 1850, and these were also adjusted to the Sprint.

Due to the increased power brought about by the new engine, the rest of the drive line has been upgraded to withstand the extra torque. The gearbox and differential have been replaced by a version of those fitted to the TR and 2000 cars, albeit with a gear ratio close to the gearbox. The brakes have been updated with new padding materials at the front and the installation of larger drums and a load sensing valve at the rear. Other changes to the Dolomite standard included the option of a limited slip differential. The optional overdrive and automatic transmissions for the 1850 model were also offered as options on the Sprint. Initial models were offered only in "mimosa yellow", although other colors were available from 1974.

At its launch, the Sprint cost 1,740 pounds, which compares extremely well to similar cars from other manufacturers. The press gave Dolomite Sprint an enthusiastic welcome. Motor summed up his road test (subtitled "Britain is leading the way") with brilliant praise:

... the Sprint must be the answer to many people's prayers. It is well equipped, compact, but deceptively spacious. Performance is there in abundance, but the economy is good and the model's manners are impeccable ... Most importantly, it is a tremendously satisfying car to drive.

A press release dated May 1973, from the Public Relations department of BL, states: "To recognize performance