gymdent

I've got 100 miles to go before my 2,000 mile break-in is over and plan to switch to Royal Purple. This will essentially be an autocross and occasional track car.

At what mileage is it advisable to change from regular to synthetic? Or can you break-in a rotary with synthetic? Many high end cars come right from the factory with synthetic so it's difficult for me to believe all those manufacturers could be wrong.

I've heard the argument both ways on different boards, as to whether or not one can use synthetic for break-in. I don't believe this facet of synthetic oil has been discussed on this forum. Someone has to have some up-to-date knowledge that is backed by reliable research and testing. Hearsay and regurgitation of 30 year old chatter is not a good foundation on which to base one's recommendation.

Steve

04RX8man

synthetic is not to be used in this motor at all.....However quite a few ppl use the royal purple oil and it's ok I would personally wait till 2000 or 2500 b4 switching on any car but in this it say not to use synthetic so i prob wouldn't

kersh4w

iTrader: (3)

congrats you just broke his last rule.

feel free to switch to synthetic whenever you want. also, the manual recommends an oil change every 7500 miles for normal driving, 5000 for spirited driving. feel free to adhere to that. i know i would if i were using synthetics.

lshu

I switched to Royal Purple synthetic at about 3K miles, following the controversial method of run-the-car-hard-from-the-start (engine warmed up of course). Just wanted to make sure the clearances are fully "seated" before I switched over. Right now my '05 MT is at 44K and running strong.

Jasonawojo

iTrader: (2)

Did the same when I got my remanufactured engine, switched to RP synthetic after 3K miles.

gymdent

Yes, that is a philosophy that many follow. However, my point is what is the basis for this thinking with modern synthetics and modern engines which, from day one, have much closer tolerances than years ago?

Why would Mercedes, BMW, Porsche, Corvette, etc. put synthetics in from the factory if it were not optimal?

If I'm not mistaken, isn't there anyone on this board with some firsthand knowledge? Is it Rotary God?

gundarx

Google "break in secrets".. read it for a day with an open mind.. modern engines surely have much better tolerances but in no way are they made perfect enough to match the different parts' surfaces.

The reasoning behind having factory-filled syn. oil is probably to protect rich, ignorant car buyers that probably don't change their oil until 10000000 miles.. syn. oil has better detergents and resists shearing better and stands up to longer oil change intervals (though the oil will def. be dirty). Proper owners in the know will still dump the factory fill syn. for dino oil for break-in.

I did a hard break-in on my '07 which only had 6 miles from the dealer lot.. had it idling about 20 minutes to warm up and redlined it several times upon hitting the highway.. came to the dealer the and did an oil change the next day @ 60 miles (dealer could not believe it).. another change came at 500.. another at 1000.. another at 2000. Some have called me nuts for doing this but I stand by it.. I do know it takes allot of convincing power to persuade others to follow though

I can say that the car has felt faster and faster every time I've pushed it than before, so I think there is still breaking-in left (@ 4000 now). I'm very favored to using synthetic but from what I've read and experienced, I think it's best to hold back on changing to syn. until more miles have built up. I've been premixing since 1,000 to add additional lubrication/protection without resorting to switching the engine to syn. oil.