Triumph Stag: the V8 grand tourer that lived down its reputation (1970-1977) The Triumph Stag was a glamorous Michelotti-styled 2+2 convertible with a bespoke 3.0-litre V8, conceived to rival the Mercedes SL but undone by a notorious cooling problem. A guide to the engine saga and why it overheated, what a properly sorted car is like, what to look for when buying, and what they are worth now the reputation has been rehabilitated.