Oil change interval

[dansk]

Anyone know specifically why DC calls for an oil change every 3000 miles? All of the technical studies I've read where oil is sampled and changes noted SHOW that it really only needs changing every 7500 miles for regular oil and at about 12,000 at a minimum for synthetic. Even my diesel truck is a 5000 mi. interval because it uses the oil at very high pressure to fire the injectors so they don't want the viscosity to breakdown at all. For warranty issues, I'll stick with 3000 miles for now, but Ithink it's very conservative. A second question is, does everyone that buys a car FROM DC get an oil change card that guarantees the price you pay at the dealer for life, or is this something specific to my dealer? It lists cars at $19.95, trucks at $25.95, and diesels at $35.95.

[EMB]

The DOD, Displacement On Demand, uses oil/oil pressure to lock the lifters on the cylinders, via a "pin" that holds the valves closed...it is oil activated.
If you let the oil get dirty, or thicken up, it will not function as smoothly as is does now.

Besides, 3000 miles has been then standard for cars a long time...and changing the oil and filter on a regular is one of the best things you can do for any engine...it carries a lot of heat away besides providing lubrication.

Shoot, if your getting 7 quarts and a filter change for $20.00...pretty cheap insurance, dont you think?

Ed

[Fred]

3000 miles is for severe duty use, like police and taxi... The standard schedule calls for changing it at 6000 miles

[dansk]

That's the first time I've heard of a 6000 mile option, I'll have to go back and read my owners manual again. Also, I have to pay the 26.95 for the oil changes, remember, the magnum is classified as a truck by DC.

[linuxkidd]

It's actually listed in the service book.. ( the one w/ the tear outs that the mechanic is supposed to fill out so you have a record of all your maintenance )...

Flip it to one side, ( Schedule A ) it's every 6000 miles... Flip the book over ( Schedule B: for heavy use ) it's every 3000 miles..

[jtkirk]

I was told that Schedule A doesn't apply for cold climate driving (like here in Boston). It might be different in the South or Southwest...

I also asked the service manager about signing my service book each time - he said it was unnecessary, because the service computer at the dealer is linked to a central DC database. They have the complete record of my car's maintenance as long as I get work done through them.

[Darth Hemi]

Who can you trust for good information regarding oil change intervals? The people that know have an interest in maximizing the number of oil changes you do. The dealership gets twice as much $$ if you change every 3k miles vs every 6k, same for the oil companies. I know that when I picked up my RT-AWD on Monday the salesman went through his 'Here's your owner's manual spiel' specifically so he could try to convince me that "living in Columbus OH means that I have to follow the heavy use maintenance schedule". It was obvoius that he was trained to make that point to maintain the dealerships revenue stream.

The auto manufacturer could tell you the truth, and I think they try by listing heavy/normal use in their service books. It could be a good marketing point for a vehicle to have a lower cost of ownership due to lower service requirements. I know that my wife's MB C230K has a 10k mile oil change schedule.

My advice, and my plan, is to read the owners manual and judge for yourself whether you fit the 'heavy use' or the 'normal use' case and act accordingly.

[SCMagnum]

I drive quite a bit and don't have the time to change my oil every 3 weeks (every 3k). I have found that changing my oil every 5,000 miles works great for me. Not to mention pretty easy to figure out when I'm due for a change. This has worked on my last 5 or 6 vehicles just fine. I have moved my 99 Dakota to semi-retirement now with over 180,000, and I got rid of a Mazda with 215,000 a few years back. All following the 5,000 oil chage