Originally Posted by badpinoy

you think if i go on a road trip during the break in period will be bad for the car?

Originally Posted by nabbun

The thing about Conventional Motor Oil is that is has gotten better now.

They have less impurities in them and can run to 5,000 miles instead of 3,000.

But, the additives in the oil will only last about 3,000 miles.

So, it'd be better to just stick with 3,000 miles until they find additives that last longer =P

If you're going to go synthetic for the long term benefits, switch to synthetic at about 15,000 miles and use it from then on.

Older engines has carbon deposits built up so switching right away would loosen up the deposits and could be harmful to your engine.

Use an engine cleaner for high mileage vehicles right before you fill up your tank (or however the directions say) and then switch.

Synthetic oils will last a lot longer because they pretty much don't have any impurities left.

But the additives in them don't last as long as the oil itself will either.

If you are going to run Synthetic, and drive aggressively or in the city, then change them at or around 7,500 miles.

I'm not saying this is how it's done or it is the final word.

Only if you want the best out of your oil and engine =P

Originally Posted by nabbun

engines are made with such tight tolerances these days that break ins aren't really required as much and you can run lighter viscosity motor oils. hence, toyota/lexus now recommends 5w-20 instead of 5w-30. there many makes and models that come out of factory with synthetic oil such as all porsche models, chevorlet corvette C6, etc. It wouldn't hurt to put synthetic oil in your newer cars. Just becareful with cars with high mileage (due to carbon deposits that might have built up that will be freed by switching to synthetic and possibly harm your engine) and older engines (such as cars from the 70's and before. they might have sealing/leak issues when making the switch to synthetic. have a qualified/experienced/reputable mechanic perform a seal check and confirm it is in good working condition b4 making the switch. also try researching about your older make and model to see if that engine is prone to motor oil leaks when making the switch. i'm pretty sure people have already tried what you are about to do)

Originally Posted by Dj_AmtraX

Correct me if I am wrong.

The factory runs the car through a track for testing (about 5 miles) before it goes on the ship to the dealership.

Originally Posted by LexusTexas

But face it, if someone test drives your car at the dealership they aren't too concerned about a break in period, only how fast it will go. Mine had 20 miles on it and still had the wrapping when I bought it, how did they get there?

Originally Posted by lobuxracer

OEM pistons are cast not forged. Also, yes, pistons are in a plastic state at full load. Look at my avatar. See the orange glow? What do you suppose the top of the piston looks like at this load? This is also why when I was building bike engines we saw more power from Cosworth pistons than anything else. They chose their alloy based on strength at temperature and nothing else. We typically saw 4% better power with Cosworth.

Pistons are not evenly heated. Their grain structure, even when forged, will undergo significant change as they are initially heated and cooled. This is precisely why I advocate a break-in process that gradually increases load while allowing a 5 minute cooldown period between load sessions. This way the pistons are not thermally shocked in a way that will cause them to lose the shape the manufacturer spent so much time and effort to achieve.

Used pistons require NO break-in, and rings can be broken in with a few short full throttle runs terminated by rapidly closing the throttle to pull oil up past the rings and help remove the metal shavings from initial ring wear.