Wait on Synthetic in new engine... WHY?

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Sep 10, 2002
Most seem to think that the rings of an engine in a new vehicle (US made) break in pretty quick, so why run on dino for 3k or more before switching to synthetic. What would still be breaking in?

Thanks, Scott
In the first 5k-10k miles, you will generally see higher lead and iron #s on a UOA from bearings and other parts. Since most people run synthetics for a longer period, it makes sense to do a few 3k mile changes to get out the wear metals.
GC is Factory-Fill in Audis, 1st change 5,000-10,000 miles
I don't think there is a reason to wait with synthetic until after a certain "break in" period. Most of the high powered sports cars and performance sedans come with synthetic right from the factory.
The only reason I could see using dino first is the fact that in the first 3000 miles I like to do three oil changes to clean out the engine from initial break in contamination. Dino is cheaper to do this. I like to change first at 500 - 7500 miles, then again at 1500 to 2000 miles and again at 3000 to 4000 miles before going to regular OCI's

If you have ever seen how contaminated, dark and dirty the factory oil fill is after 500 to 800 miles, you's do the same .....
Something to consider is some higher end stuff is runin at the factory before it is put in the car, this could be done with different oil then the synthetic put in. Plus some vehicles do suffer from oil usage is switched too soon and switching back to dino for awhile cures it, maybe the engines that get synthetic right off the bat have a different crosshatch and ring package meant to work with that.
I changed mine at 500 and used the supertech for another 500. Went with synthetic after 1K. Went with 2 5K intervals until I went with extended OCI with synthetic...but it depends on your driving conditions, test your oil and use common sense on how long your synthetic can handle the type of conditions your engine must endure.
In discussions with a GM engineer, synthetic oil has shown no difference in break in time on new engines put on the dynomometer for testing.
Auto engines are made different today with tech.. engines will break in a lot sooner and synthetic is no problem. It's just natural break in period where the most wear will occur and I think why most will say to use short dino intervals until most breakin wear will occur and then go with synthetic why it would make more sense. Dino or synthetic new engines go into a break in period and who WANTS metal particals in a new engine. I changed my first at 500 and went cheap with Supertech for another 500. Went with 2 straight 5K with synthetic and then extended OCI with synthetic. Engine is clean and a cleaner engine with synthetic will perform to it's potential.
I went to synthetic (M1) at 500 miles, and burn very little oil (about 1/4 quart every 7500 miles). 50k on the car now.
This is one of the myths that persist with synthetic oils.

Go to Mobil1.com and under link Why Synthetic see Myths about synthetics.

About the only logic to putting it in a new car that did not come with it is to not want to spend the money till an oil change is necessary.

[ June 03, 2004, 08:51 AM: Message edited by: Mike ]
I agree it is just a myth probably stemming from the whole thinking that synthetics are the godsend of lubricants (egs. you can go 1 mil. miles with no engine wear, 25k OCI's, etc.).

Now that we know these myths are untrue, you can safely use synth's from day 1. However, why waste perfectly good oil. Keep what's in the car for 3,4-5k mi. and then start with the next interval...
"In discussions with a GM engineer, synthetic oil has shown no difference in break in time on new engines put on the dynomometer for testing."

I'm not surprised, JohnnyG. I've believed this for a few years, now ... just like I believe synthetic offers no additional wear protection over mineral-based lubes in the short run.

My main reason most people should not use synthetic oil in most new cars is because you are well advised to change the oil in a new car frequently to flush out the break-in debris ... even if it is not as bad as in decades past. Wear metal contaminants can still be a source of abrasion.

Only when manufacturers use some sort of break-in oil and explicitly state that the oil is not to be changed before a certain number of miles have accumulated would I deviate from this practice.

And even then, I have a hard time going more than 3,000 miles on the factory fill.

--- Bror Jace
My recommendation with Amsoil is to do a couple of low mileage oil changes with conventional oil, then switch to Amsoil @ the 5000- 6000 mile point. Change out the first batch of Amsoil after 8000-9000 miles, then go to an extended drain program if you're comfortable with the idea. In other words, you should really have 12,000-15,000 miles on the engine before STARTING an extended drain program.

It can take quite a while on some engines - particularly diesels - to get the optimum ring seal and shed the bulk of the break in wear metals ....That's not the time to run long drain intervals.

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