Achieving Euro5 certification is a major milestone for Ural, but what exactly has changed?The two main challenges for Ural were emissions and noise and this became the main technical focus.The change to Keihin EFI in 2019 paved the way for the development of the necessary upgrades to meet the very stringent demands of Euro5.The exhaust system had to be completely redesigned and now consists of a custom built, stainless-steel, 2 into 1 system with a high-level, large single rear silencer. This significantly reduces noise and increases ground clearance as well – a welcome bonus for those venturing off-road.The exhaust system now contains two pre-catalysts and two large diameter main catalysts. An inbuilt “vacuum valve” is actuated by engine vacuum, controlled by the ECU via a vacuum relay, giving rapid warm-up of the catalysts at low R.P.M. and full unrestricted power at higher R.P.M. The Keihin throttle bodies had to be adapted to provide vacuum take-offs to support this functionality.The pistons were recently redesigned to increase compression ratio by 20%. They are still gravity cast from NASA388 aluminium/silica alloy – with a hard-anodised crown and top ring-groove. Various applications of high-tech coatings on the piston skirts, ring grooves and rings, as well as a phosphate coated gudgeon pin, all reduce internal friction. Precision machining and reduced tolerances all contribute to longer service life.The centre stand has been completely redesigned to make it easier to lift and lower the bike safely – whether you’re in the workshop or out on an adventure.All of these features will be delivered as standard on 2021 model year Euro5 Urals and new Ural owners will undoubtedly benefit from this comprehensive range of mandatory technical improvements.