Poll regarding oil changes / filter replacement

[able2ski]

My 04 F350 deisel work truck (the one that pays for my 2000 Cab.) suggests a regular oil change service interval of 5K miles. I pull some significant weight, so I do oil changes much more frequently. My practice has been to change the oil (Rotella) every 2500 miles, but only change the filter every other time. The monster Ford filters arent cheap (nor is 15-17 quarts of Rotella!), but since I'm still doing better than a straight oil / filter change every 5K, I have always felt good about my maintenance practices.

But I wonder........Ford or Porsche........if one were inclined to do better on one aspect of the service interval and "skimp" on the other, which would it be? Oil or filter?

Although I've never measured (or even tried the practice) on either vehicle, simply changing the filter will result in some oil loss which would have to be replaced anyways.......hardly anything in the Porsche, but a full 2 quarts in the Ford! In comparison, just the oil change leaves behind an equal quantity of nasty oil in the filter system, but far less a percentage in the Porsche than the Ford.

[msindi]

Not sure there - I change both oil and filters at every 3000-3500 miles...

[able2ski]

While working on our vehicles at home today, I realized I mispoke regarding my '04 Ford F350. It has the oil filter at the very top of the engine, an oil drain gets everything.

My previous truck, an '01 F350 with the older 7.3 liter deisel had the bottom filter arrangement which held a whopping 2 quarts.

Anyways, I'm still curious what practices others follow.

[KarlS]

I always change oil and filter in all my vehicles at the same time. My tow vehicle has a gas engine but it gets new oil and filter every 3K miles. I change the oil and filter in the Porsche once a year, which means it goes about 6-7K miles. I use Mobil 1 in the Porsche and whatever non-synth oil is on sale in the truck.

Karl