Gearclash Posted October 30, 2022 Share Posted October 30, 2022 3 hours ago, Farmall 1466 said: Do SCR systems not have a DPF? Than sooth emissions would be way too high to pass emissions tests right? And EGR/DPF systems do make use of SCR too right? Virtually all new tractors consume AdBlue I think and otherwise NOx emissions would be too high? So what is the difference? SCR (Selective Catalytic Reduction) is to reduce the emissions of NOx. DEF (or AdBlue to you) is used to this end. EGR ([cooled] Exhaust Gas Recirculation) accomplishes the same thing, but I see EGR as being a much poorer choice overall due the negative effects on the engine. DPF (Diesel Particulate Filter) is there to remove the particulate emissions (soot) from the exhaust. The nature of diesel combustion is such that if the engine is tuned to reduce particulates, NOx goes up and vice versa. CNH apparently has chosen to go the route of tuning their diesels for a minimum of particulate emission, which means they hardly need a DPF, but have a relatively high use of DEF. It is perfectly possible for a diesel to have both a DPF, and use SCR. Each is intended to control a different pollutant. 1 Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.