I switched to the top level Amsoil Diesel 5W-40 in my Duramax truck when it had 2,000 miles on it and, with 98,000 miles on it now, it's never had measurable oil consumption between changes. I've never bothered to get the oil analyzed because I use the highest quality oil available (price is not a consideration) and change it every 7500 miles. Oil analysis is primarily for those who economize on oil quality or who maximize oil change intervals.

I had always used Land Rover spec Castrol 5W-30 in my Td6 (also bought new) and changed it every 7500 miles. I switched to Amsoil Signature Diesel 5W-40 at 60,000 miles after watching the previously cited YouTube video and immediately noticed smoother engine performance. I've only driven 3,000 miles since switching oil and haven't decided if I'll get it analyzed at the 67,500 mile oil change.

 

Given the Td6 engine's history and reputation (if I'd known when I bought it that it was a Ford engine I would have passed) my highest priority is preventing the engine from grenading. Ergo, I want the best available lubrication and protection against wear/scuffing. IMHO, from the data I've seen, nothing is better than Amsoil Signature Series Diesel oil. Replacing a DPF is financially feasible. Replacing a blown engine is not.

 

FYI combustion engines do use oil. Modern technology made it minimal, but they still do.
The only way you have no measurable consumption is when you have fuel diluting the oil.
but you choose not to test it....

 

OK, oil consumption is minimal, i.e., slightly below the F on a Duramax cable dip stick between changes (I call that negligible). I could measure that amount by adding enough new oil to bring it back up to the F, but doing that just before draining the oil to change it would be dumber than a Democrat. The truck is pre-DPF and if it belched black smoke (never does) or had poor fuel economy (it doesn't) then having the oil analyzed would be an appropriate trouble shooting step.

 

I do my oil test for confirmation, that the intervals I am using (I use what is recommended to max) are right and also to have quiet minds.
Lot of luxury car owner replace oil and filters much, much earlier, or without measuring their wear for quiet mind.
Meaning they drop hudred$$$, if not thousand$$$ for unnecessary maintenance, yet skip $30 or $40 on oil testing, what can be very crucial in some moments.
And I do install Filter Minders on my air filters.

 

My hat is off to you for managing oil changes the smart way. Being lazy, I've always figured that if I'm paying ~$100 every ~400 miles for fuel, I can afford to pay ~$100 every 7500 miles for oil and filter. I do bottom drains after raising the vehicle and dropping the skid plate. There's nothing wrong with extracting the old oil through the tube for that purpose but I recommend doing at least one bottom drain and replacing the drain plug with Gold Plug Magnetic Drain Plug, Part # MP-02T ( ). The neodymium magnet will reduce engine wear by capturing ferrous particles.

 

I am new to Land Rover, but coming from Mercedes Benz community, some fellow owners were quoted $2000 for ServiceB, so there is more to it.
For me cars were always a hobby and I have mechanical degree in non-automotive fields, what helps a lot.
Than, even I reached the age, when crawling under vehicles is getting harder and harder, reading lot of horror stories, how mechanics can put filter orings in wrong place, or strips the bolts makes me DIY regardless how cheap I could find mechanic.
There is Canadian member on benzworld, who has to be about 10 years older, than I am and yet he is still pretty active in maintaining his vehicles and writing about it.

 

At the last oil change (60,000 miles), while the Disco was raised I also changed the front and rear differential fluids and transfer case fluid (also changed fuel filter, engine air filter, and cabin air filter). Planning to have the transmission fluid changed at 80,000 miles.

 

I've run the following & all seem to perform well. There are UOA reports from blackstone on the forum as well

• Shell Rotella T6 0w-40
• Liqui Moly 4600 5w-30
• Motul 8100 X-CLEAN GEN2 5W-40

Ford's oil spec sheet attached for reference.

 

Which one are you currently running since I've heard good about the motul 5w40