Depends on the Region You Live In...
...I use 10w30, got just over 41k on the ODO, my VX is pushing 5 years of trouble free miles using mostly FRAM filters BTW :)
K & N was a marked improvement in air filtration. As for oil, and others, fuel, PCV, etc... keeping everything new every 3000 miles, and using major manufacturers products that meet or exceed the owners manual (ISUZU) specifications should be enough to keep any vehicle in good shape for many years perhaps decades:yes:
If you have a '99 oil pumper
with the old style oil control rings try 3 liters of 5W 30 and 2 liters of marvel Mystery oil, also put 2 ounces of MMO in tank per 10 gallons of fuel.
