Isn't that a diesel? We don't have them here in the US. Mobil 1 0w40 is fantastic oil but it is not diesel rated as far as I know. IMO you need to stick with diesel oil. There are some Jeep guys from the UK on here hopefully they will chime in.
K&N air filters let a lot of contamination in, not a good idea for a diesel either IMO they run dirty enough as it is. Actually the Mopar air filter is great if you can find it, otherwise a good aftermarket would be a better choice.