I use Mobil 1 oil, every 5000 miles,
5W
40
Turbodiesel Truck
fully synthetic engine oil and very satisfied with it.
Many years ago, it wasn`t always easy to find on the shelves but by now I always see it at Autozone, gas stations, Walmart etc, Advance Auto Parts etc.
The cost of our oil change (without the filter) is gonna be around 50 dollars because you need to buy 2 gallons... and, you`ll still have approximately 1 quart of new oil left, good for top-ups on the road, if needed. That`s about 1usd `spent` on oil for every 100miles.
https://www.walmart.com/ip/Mobil-1-5...RoCKAUQAvD_BwE
Be careful, the Walmart link is misleading, the oil is 5W40 but it looks as if it was 15w40
I bet this Mobil 1 is good enough to use for even up to 8000miles but I guess this oil isnt too expensive to even make experimenting worth it. And you love your d24 and you want it to collect a huge amount of miles, right?
Also, in case your car `eats` some oil (some cars do use oil up to a quart/1liter per circa 1000miles), then by the end of your 5000 miles you actually have
will have refreshed your oil substantially, just by regularly adding oil as car consumed it... (by topping up at each check-up at the dipstick) ...so... in 5000miles you actually replaced up to 5quarts of the total capacity of your engine which is 7 quarts...
something to consider and add in, for some unlucky owners LOL.
((So in my opinion, for those who have their cars consuming motor oil, oil changes don`t have to be religiously 5000miles. The `older, used part` of your motor oil regularly gets diluted/mixed into something healthier as you go, every time you top up the system with some fresh oil. REGULAR CHECKUPS are still a must! Actually it is only the level checkup that is able to tell you what is going on inside, oil quantity-wise,
so... I would say: pop that hood before your trips
or at least once every 500miles at the most. Most of the existing running d24 d24t engines are well over 25-30years old today. ))
PS
it seems these engines can lose a lot of oil at and around the valve cover, especially if the gasket is too old, or a wrong kind (2-piece cork gasket is really bad) or in case the top cover got installed incorrectly, too loose too tight or misaligned/bent etc by wrong&uneven torque values, wrong tightening sequence etc. Everything counts
I have successfully reused the Goetze valve cover gaskets before so it is definitely worth the extra bucks! About triple the price of the cork junk 2-piece ones BUT IT`S TONS BETTER and seals really really well.