I do 6000km or 6 months with Delo 400 on all my vehicles, my engine internals are quite clean, I have no consumption issues even on my high mileage vehicles, would be a pity to throw away oils like Delvac or Delo down the drain at 3000km.

I attended a lubrication seminar in the past where a guest speaker discussed this subject. The basics of his speech were that the oil was tested at pre-determined intervals, mostly every 3-3500 miles to start with and then 5000 mile intervals after the first three analysis. The FILTER was changed around every 5000 miles. After running the same oil in the vehicle for 25,000 miles, the owner got nervous and had the oil changed. The test results did not indicate the oil needed to be changed. The vehicle was one of a vehicle in the owners fleet, subject to both on road and off road conditions. My question is this, why do we set different standards for industrial equipment and vehicles? If I have a piece of equipment that uses a hydraulic oil, I will change the filters on some frequency and have the oil tested on some frequency. The engines in our vehicles are not asked to operate in harsher conditions than we ask our industrial equipment. Instead of changing the oil more often, why not have your oil tested? At a predetermined parameter, decided by testing, the oil or filter would be changed. This would keep us from changing, and wasting, oil. Any thoughts on that?

Back to the orinal question, someone touched on this.

3,000 miles is the dealers number.

What does the owners manual require?

I received a coupon book for oil changes with my 2006 Dodge Ram Hemi. Dodge printed the coupons for every 6,000 miles. My owner smanual says 7,500, I think.

Dealer puts a sticker in the window reminding me to come back in 3,000 miles.

Go by the owners manula if you have a warranty. After that, go for a longer interval.