I suggest some lite reading from http://www.sae.org "Title: Extended Oil Drain Intervals - Conservation of Resources Or Reduction of Engine Life (Part Ii)"
After reading that you may never change your oil again at even 10,000 miles!

There are millions of miles of oil analysis that not only prove short duration changes increase wear but also result in a lack of additive activation in the motor. If you own a Jiffy Lube then I would expect you to subscribe to the "3,000 mile Mentality" myth.

Oil addiitives are activated by heat and pressure. Due to the additives having to hold up over time ie longer than 10,000 miles the formulations take a certain period of time to become active in protecting the motor. Draining the oil at lets say 3,000 miles simply means the additives have just become active at the point you are draining your oil! In other words you are increasing wear by about 500% doing 3,000 mile drain intervals!

Oils that carry the extended drain ratings such as 506.01, 507.00 etc mean that the additives are formulated to remain active for periods up to 2 years, 40,000kms or 640 hours of usage. Oils like Mobil 1 0w40 are formulated to withstand 400F sump temps WITHOUT breaking down and losing viscosity. Furthermore the oils cannot break down due to the PAO makeup of the oil. These oils do not rely on elastomers like the conventional oils do. This means that the oil can fully protect your motor at any temperature without the conern of thermal break-down and thinning out of grade.

If you doubt the 10K oil change intervals perform an oil sample at 1,000 miles. Most cars with a fresh sump of oil will peak out at the 1,000 mile mark. After that the wear metals may increase by only 5-10% over the course of 10,000 miles! Nearly 90% of the engine wear occurs in the first 1,000 miles on an oil change! Increasing oil change frequency increases the duration your engine spends in the activation period of the additives and greatly increases the damage in your motor from failing to follow the guidlelines of the manufacturer.

Just looking at iron in a VW motor typical readings are around 20-35ppm after 15,000 miles of use maximum on a motor that has more than 60,000 miles. The oil filter is not capable of filtering this much metal simply because the wear metals are so small they can't be filtered from the oil. Also because there is so little wear metal you do not get wear as a result of the metal being suspended in the oil.

Dispersants require time to bond to the wear metals and byproducts in your engine oil. As byproducts such as soot (gasoline or diesel make soot just different sizes which discolor the oil) are created additives coat them and prevent them from clumping and becoming larger. Typical soot particles in diesel oil are in the nanometer range in terms of size 10 times smaller than what any bypass filter can even capture which is rated at 2 microns absolute. Your oil filter in your motor is rated at capturing particles in the 7 micron range with only a 75% first pass rating...Bottom line is your car would last forever if you change the oil every 20,000 miles and NEVER replace the oil filter simply because your motor is not making enough metal or by-products to ever get captured! Oils especially those for diesels can handle upwards of 8% soot, that my friend is a LOT of soot! to put that in perspective a typical motor after 25,000 miles without an oil change or filter change will only have 1% soot in the oil. This oil will appear tar black yet the oil still has 80% of its rated levels of protection remaining!

Most oils are limited by time in the sump rather than miles due to sulfur in the fuel. Most gasoline motors can safely go 2 years between changes when using quality oils formulated for extended drains such as Mobil 1 0w40 and Truck and SUV 5w40. These oils along with those sold as VW 506.01 have very high TBN ratings that neutralize acid formation for upwards of two years (1 year in diesels due to higher sulfur content wich causes the acids).

Heres the deal, forget the myths about frequent oil changes and basing your perceptions on how the oil looks. The best advice is use a quality oil and drain it at the specified interval. The worst thing you can do to a modern car is overmaintain it, yes this is possible due to the very specific regimine that VW engineers figured out to keep your car running at peak performance with maximum durability.