If you want the oil to come out like new or only a light tan is to run straight non detergent oil but then without detergents scrubbing and eating away sludge, varnish and combustion acids, it's a failure oil.
Black or dirty dark oil drains has me thinking the engine for one is running way too rich like the problem D1's had with over fueling on cold starts a big issue with LR that took an aftermarket perforfance chip to correct, must add a big kick in the butt performance increase also including better fuel mileage.
Dark oil with these so called "high tech roller OHC" engines, (a 1906 fishing boat engine manufacture came out with a roller rocker OHC engine so not a new design) running high detergent quality oil say from day one there shouldn't be sludge and varnish buildup beside the small normal amount after 50K miles.
Carbon particles from combustion an excessive amount causing dark to almost black oil (running quality detergent oil) leads me to believe bad, tired or a bad designed compression rings with possibly the wrong type of cylinder bore finish before assembly. I'm not leaving out the wrong material cylinders and rings combinations. Made in India or China LR's, go figure.
A well sealed engine, rings to cylinder bores even at high mileage will still have dark tan oil at worst not this almost to black oil mentioned above.
Anyone ever run a differential compression check on their dark brown to black oil producing engines? Tight efficiently sealing rings to bore reduces the amount of carbon wearing particles blown past the rings into the oil now increasing internal engine wear.
Hell my "antique push rod engine", built up with 64, 66 & 69 parts of 379K miles the oil drains out light to medium tan highway vs in town driving at 4,500 miles oil changes. This 454 cu/in holds 13 1/2 quarts oil. Total Seal gapless rings. A Ford engine not a POS chubbie 454.....~~=o&o>.....