With the BMW M3 Sport Evolution gaining notoriety with DTM racing homologation, Mercedes Benz responded on March 1989 with the 190 E 2.5-16 Evolution, debuted at the Geneva Auto Show to enthusiastic acclaim. Only 502 units of the Evolution model were produced for homologation in compliance with DTM rules of a minimum of 500 units of production. By the beginning of June 1989, all cars had not only been produced but pre-sold, each one in blue-black (199 U) metallic. Because these were only built for homologation, at great cost to Mercedes they were only ever supplied in LHD. The vast majority were sold by MB directly to eager owners in Germany. The Evo I, as it came to be called had a new larger spoiler and a widened track with resulting a wider body, deeper front air-dam and a larger rear spoiler including a wedge section, which helped increase downforce, Body modification rules to comply were minimal and meant the road cars produced had to look just like the racing versions but changes were certainly not only skin deep on the Evolution 1. The already excellent multi-link MB rear suspension was enhanced with 23% stiffer spring rates & matched shock absorbers compared to the standard 2.5-16's & included SLS suspension to each wheel, providing improved ride & control. This adjustable hydro-pneumatic suspension allowed a height variation of 3 positions through a range of 30mm via a 3 position dash-mounted switch. The Evo I's output was similar to the 202 bhp of the "regular" 2.5-16 but was equipped with a re-designed engine of similar capacity but with a squarer bore & stroke (97.3 / 82.8) to allow for higher rev limits & power in racing applications. On these production models, the rev limit was set at 7250 rpm compared to the 7000 rpm of the "cooking" 16V's. Additional changes to engine design included: " lightened rotating masses, improved lubrication and altered camshaft timing ". Cosworth also listed a project code "WAC" for the development of the short-stroke Evolution engine.