Have a 2004 disco II with Bosch engine. Had oil changed at 52,150 and dealer service done as per manual. No problems noted from service. Checked oil after service to be sure topped off at 6.8 qrts, it was. Checked oil at 58,322 was low by 3.5 qrts. (i was following dealer service intervals on oil, but that will now change to every 3000 ) Having oil changed today (58,420) and replaced with 15/40 for summer heat. Dealer suggested this too. I plan on monitoring every day for 1 week and then every 500 miles to see what consumption rate is. no visislbe oil leaks on engine or underneath, except for slight oil residue on top of left valve cover near PCV valve tube. There is also no visible blue smoke or burnt oil odor. Do these engines use oil? The dealer told me it was not uncommon to see 1+ qrt usage between oil changes.