I have seen recommendations for waiting until the manufacturer's first
scheduled oil change or a minimum of 2,000 miles in new gasoline
engines before using synthetic oil.
(My personal inclination is to get synthetic oil in there as soon as
possible when an engine is new, but would not do so if I now see it as
actually bad for the engine)
The only explanation I can think of is that conventional oil is more
abrasive and will wear down the microscopic metal imperfections in the
cylinder walls and rings, whereas synthetic is too slippery to permit
the needed abrasiveness of conventional oil.
Does this explanation make sense ?
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
Yeah, what he said. You need a little friction during the break in
period to properly seat the rings, UNLESS the manufacturer specifically
states that this is not necessary. Some synthetics can be so slick
that they don't allow this to happen, and you end up with glazed
cylinder walls an an oil burning engine.
GTP Dad wrote:
So, is it that "glazing" , and slickness of the cylinder walls, which
is something that one would seem to want,(at least later in the life
of an engine) is desirable only after the small (possibly) existing
metal particles on the cylinder walls and rings have been rubbed off
by the dino oil non glazing period at the start of the new engine use?
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.
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
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
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
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
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
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.
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