I agree with the manufacturer's recommendation.  The 2000 miles on dino
oil will allow the rings to seat properly in the cylinders and prevent
oil consumption.  Putting synthetic in right away will prevent proper
break in and can cause issues later.  Some of the more high performance
cars like the Corvette comes with Mobil 1.  However, these engines are
individually run before shipment and are already broken in at the
factory.

Running the factory fill conventional oil for the first 3,000-5,000
miles won't hurt at all, especially with today's SM-rated oils, but the
recommendation against using synthetic from day one seems to have been
obsolete since the mid-1980s, at the latest.

Below is a synthetic oil FAQ put out by Mobil about 10 years ago.
Dial 1-800-ASK-MOBIL for more information.

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Q:  HOW OFTEN SHOULD I CHANGE OIL WHEN USING MOBIL 1?

A:  A number of factors influence oil change frequency, including
   your driving habits, typical road conditions and environmental
   conditions. We recommend that you follow the oil and filter
   change frequencies shown in your owner's manual, especially
   during the warranty period. The excellent protection you get from
   Mobil 1 gives you the confidence to go the full length of the
   mileage or time frame recommended for changes by the
   manufacturer.

Q:  WHY DOESN'T MOBIL CLAIM 25,000 MILE DRAIN INTERVALS ANY MORE?

A:  Each auto manufacturer develops and specifies oil and filter
   requirements for their vehicles.  Mobil respects their oil drain
   recommendations and does not want to put the consumer in a
   position that is in conflict with the auto manufacturer
   recommendations.  While Mobil 1 has given excellent results in
   extended oil drain tests, we prefer to remain conservative with
   our oil drain recommendations.  We recommend that you can go all
   the way to the maximum mileage or time shown in your owner's
   manual for oil changes when using Mobil 1.

   This allows the reserve protection capabilities of Mobil 1 to
   cover unusual or unexpected driving conditions.

Q:  WHAT VISCOSITY GRADE SHOULD I USE?  WILL A HIGHER VISCOSITY GRADE
   (15W-50) PROVIDE BETTER PROTECTION?

A:  Mobil recommends that you follow your engine manufacturer's
   recommendations as indicated in the owner's manual.  For maximum
   wear protection and maximum fuel economy, use the lightest oil
   viscosity that is recommended by the engine manufacturer for the
   temperature range expected.  Heavier oils lower fuel economy and
   rob horsepower.  For normal driving conditions, 5W-30 and 10W-30
   are the primary current recommendations of automotive
   manufacturers.

Q:  DO I NEED TO FLUSH MY ENGINE BEFORE CONVERTING TO MOBIL 1?

A:  No.  There is no special preparation necessary when converting
   from conventional oil to Mobil 1.  In fact, Mobil 1 is compatible
   with conventional oil should it be necessary to mix the two.
   However, the superior performance characteristics of Mobil 1 will
   be reduced by diluting it with conventional oil.

   Mixing different types of synthetic oils is not recommended since
   different oils may be composed of different types of synthetic
   stocks.  Change the oil and filter before changing from another
   synthetic oil to Mobil 1.

Q:  WHEN CAN I START USING MOBIL 1?  CAN MOBIL 1 BE USED IN AN OLDER
   VEHICLE?

A:  You can start using Mobil 1 in new vehicles at any time.  In
   fact, Mobil 1 is the factory fill for the Corvette LT-1 and LT-5
   engines. One of the myths that persists about Mobil 1 is that new
   engines require a break-in period with conventional oil.  Current
   engine manufacturing technology does not require this break-in
   period. As the decision by the engineers who design the Corvette
   engine indicates, Mobil 1 can be used in an engine from the day
   you drive the car off the showroom floor.

   Mobil 1 can be used in older vehicles with high mileage on them.
   However, in older vehicles, if there is a problem with oil
   consumption or leakage, it may not be economically wise to
   convert it to Mobil 1 until such mechanical problems have been
   corrected.

Q:  WILL THE USE OF MOBIL 1 VOID MY NEW CAR WARRANTY?

A:  Absolutely not.  Mobil 1 exceeds the API engine oil service
   requirements of all new car manufacturers.  This includes both
   American and foreign-made autos.  The only exception to this is
   the Mazda RX-7 rotary engine which recommends against using any
   synthetic oil.

Q:  CAN I OR SHOULD I USE ADDITIVE SUPPLEMENTS AND/OR ENGINE
   TREATMENTS WITH MOBIL 1?

A:  We DO NOT recommend the use of any additive supplements or engine
   treatments with Mobil 1.  Mobil 1 has been formulated to greatly
   exceed the most severe industry and engine manufacturers'
   requirements.  Using additive supplements will not improve the
   long-term performance of Mobil 1, and our tests indicated that
   use may actually degrade product performance.  The American
   Petroleum Institute (API) and American Automobile Manufacturers
   Association (AAMA) have stated that "certified oils eliminate the
   need for supplemental engine oil additives."

   Tests have shown that some additive supplements may significantly
   alter the performance and properties of any lubricant.  In
   several cases, additive supplements have been detrimental to
   viscosity, storage stability and reduced protection against the
   formation of deposits.