What Oil Do You Use for Diesel Engines?

[mudski]

Switched to Delo 400, Can get at the Traralgon Caltex Truck stop on princess highway (20L drums), have noticed a bit more blow by in the catch can since using it, seems quiter than when I had the penrite 10-40w semi synthetic but want to change to penrite 5-40w as then it would be all penrite oils in the vehicle or really considering the Castrol RX Super, still not sure which way to go..

I used to sell Castrol a few moons ago now. I still keep in contact with the rep who's been there for donky's. RX Super is not recommended for the ZD30's but the rep was confident that I could use it. But I wasn't. So I have kept on with Magnatec Diesel 15w40. Been using that since day dot and start ups are really quiet and I catch around 150ml of oil in the catch can every 5k service. I did switch to Delo 400 a while back after reading all the hype. After using it for 3 services the motor, used a little oil, had more in the catch can and was noisy on start up. So I switched back and haven't looked back. SCA have the Magnatec on special at nearly half price every now and then on the 10L so I stock up when I can.
One thing you need to remember though is, if you do switch oils, stick at it for atleast two changes, minimum. As different oils use different additives and your motor will react differently maybe to not what you like. But it may settle down, give it a go...

But I wouldn't be using RX super in a ZD30. TD42? Hell yes!