As has already been noted, "what type of oil" questions generally spark
Having said that, let's look at the oil change interval. When you get
your new car, read the manual, and do what it says! Whether dino or
synthetic, you're gonna need to change at the manufacturer's recommended
interval in order to preserve warranty coverage.
Once the warranty's up, you're on your own. Many suggest longer
intervals w/ synthetics. Some suggest oil analysis to determine the
intervals. My VERY limited experience w/ oil analysis is I can do an oil
change for not much more money, and KNOW I've got clean oil for x more
miles. But that's a matter of opinion.
Much has been said about when to switch to synthetics, when not to.
Several cars come from the factory w/ Mobil 1 already installed. Mobil
claims there's no need to go thru the "break-in" regimens often
suggested. While I don't agree with all this guy has to say, you'll find
an interesting read at http://www.boss302.com/oil.htm which you may or
may not find to be in agreement with what others have said over the
As has also been reported, synthetics have a very good reputation for
cleaning. This is one of the reasons it's sometimes suggested a high
mileage engine not be switched over: oil leaks can occur where old crud
is cleaned out, old crud that was actually doing the sealing! A
gentleman who posted here for some years referred to this as "the
laxative effect." As good a term as any!
Some claims have been made of great increases in fuel economy when
switching to synthetics. I won't argue that some cars MAY get better
mileage, but my experience, carefully documented, indicates no more than
a tiny increase (like around 1% or less over 10s of 1000s of miles) in
economy. Claims have also been made that the engine runs 10s of degrees
cooler. In street use, with a properly functioning cooling system, the
t-stat will regulate the temp far more tightly than that, so while I'm
not saying it can't happen, I'm just skeptical.
There are also many claims that wear is greatly decreased using
synthetics. I haven't seen a side by side test yet to prove that beyond
doubt. But the big 3 US diesel oils, Delo 400 (Chevron), Delvac (Mobil)
and Rotella (Shell) have all passed MILLION mile tests on big diesel
engines (keep in mind the warranty on many of them is 600k miles or
so!), and they're dino-based. So a dino oil isn't going to "wear out"
your engine if you follow regular change intervals w/ good filters! My
gut level feeling is synthetics probably DO cut wear IF you use extended
change intervals, but with 3-4k mile change intervals, I doubt the
average person will see any significant difference. I could be wrong.
As for my personal experience turned into opinion, Wal-Mart's cheapest
dino oil, with a good filter, changed at 3000 mile intervals, will
probably keep your engine going as long and with as little wear as an
expensive synthetic run out to 7500 miles or so. I don't know how long
you plan on keeping your car, but my '90 Loyale, which was terribly
cared for by its first owner, lived its life on dino oil. It died at
360k miles of a non-oil related "disease" (serious pinging finally took
its toll.) There's also a Camry in the driveway that has 234k miles and
runs "like new." Changed religiously at 3500-3750 mile intervals using
that oft-maligned Pennzoil. No oil related problems or excess
consumption, etc. One of these days maybe I'll start a thread to compare
high mileage engines as to dino or synthetic and change intervals...
So you pays your money and you takes your choice, as they say!
Hope you like your new car when it gets here!