Jaguar SS100 3.5 Litre
The SS100, produced from 1936 to 1940, is the car that put SS Cars Ltd — the company that would become Jaguar after World War II — on the sporting map. Its name derived from its ability to reach the magic 100 mph mark, a genuinely exceptional achievement for a production sports car in the late 1930s, and one that placed it in elite company alongside far more expensive machinery from Alfa Romeo, BMW, and Bentley.
The story of SS Cars begins with William Lyons, who started the Swallow Sidecar Company in 1922 before moving into coachbuilding and eventually complete car manufacture. The SS1 and SS90 preceded the SS100, but it was the SS100 that truly combined Lyons' talent for beautiful design with genuine high performance. The flowing front fenders, swept-back windscreen, long louvered hood, and exposed spare tire created one of the most handsome pre-war sports cars ever built.
The SS100 was initially offered with a 2.5-litre overhead-valve inline-six producing 104 hp, but the definitive version arrived in 1938 with a 3.5-litre engine developing 125 hp. The engine was a Standard Motor Company block extensively modified by Jaguar's brilliant engineer William Heynes, featuring a new overhead-valve cylinder head designed by Harry Weslake. This combination of the Weslake head and Heynes' engineering genius would form the foundation of Jaguar's post-war engine program.
The 3.5-litre SS100 could genuinely achieve 100 mph, with the fastest examples recorded at over 104 mph. In period road tests, it was praised for its acceleration, handling, and above all its remarkable value — it offered performance comparable to a 2.5-litre Alfa Romeo 8C at a fraction of the price. This formula of offering exceptional performance and style at competitive prices would become the Jaguar hallmark for decades to come.
The SS100 achieved notable competition success, winning the 1937 RAC Rally outright and performing well in Alpine Trials and other events. Tommy Wisdom and other privateer racers campaigned SS100s with distinction throughout the late 1930s.
Production was halted by World War II after just 314 examples had been built — 190 of the 2.5-litre and 116 of the 3.5-litre variant (plus 8 prototype and competition cars). After the war, William Lyons renamed his company Jaguar, distancing it from unfortunate SS connotations. The SS100's spiritual successor was the legendary XK120, which continued the tradition of stunning beauty and remarkable performance at accessible prices.
Today, the SS100 is one of the most prized pre-war sports cars. Its rarity, beauty, historical significance as the foundation of the Jaguar legend, and eligibility for prestigious events like the Mille Miglia make it highly sought after by collectors worldwide.
Provenance is everything with pre-war cars — verify chassis numbers and history through the Jaguar Daimler Heritage Trust. Many replicas exist, including Proteus and Suffolk reproductions. Original 3.5-litre cars are more valuable than 2.5-litre versions. Mechanical spares are limited but the pre-war Jaguar community is supportive. Check for corrosion in the ash-framed body structure. Originality is paramount for value.
Total production approximately 314 units: 190 with 2.5-litre engine (1936-40) and 116 with 3.5-litre engine (1938-40), plus 8 prototypes/competition cars. Production ceased in 1940 due to World War II. The company was renamed from SS Cars to Jaguar Cars in 1945.