Chewbaccsw5

Hey everyone, I have my 1990 TII turbo FCS5 and I am getting ready to drop the engine in. I've read and heard that its good to use mineral based oils in order to break the engine in faster, but is this true? It makes sense to me and I purchased some 20W-50 Royal Purple synthetic for after it's broken, but I was curious, that if I do need to break in with different oil, what brand/type do you all recommend?

misterstyx69

iTrader: (142)

Use a decent oil,but not a cheapie..Castrol GTX is good.
You see the reason that the DINO oil is used is that the Oil will get into everything,so to speak,Lube it all up and get the Crud out.,Anyways you are gonna dump the oil after a small period of running so it saves money too!..lol!
After your 500-1000 mile break-in you can use a Synthetic.

J5sense

iTrader: (3)

My mazda reman came with a huge note saying use of synthetic voids warrenty. they probibly have a good reason for it.

Evil Aviator

Mazda Motorsports recommends mineral oil for engine break-in. See page TT-22:
http://www.mazdamotorsports.com/pdfs.../97CatComp.pdf

The same goes for breaking-in a transmission or differential. Synthetic oil unnecessarily extends the break-in period, so it is better to use mineral oil.

That's because it was standard Mazda policy not to warranty the engines in our cars against damage caused by poorly-engineered synthetic oil. I don't think any of that crummy synthetic oil exists on the market anymore, but Mazda never changed their policy.

Chewbaccsw5

Thanks a ton guys, so with the Castrol GTX, which thickness do I need to use? W50?

Evil Aviator

If you like Royal Purple, they sell special mineral-based break-in oil. Just keep in mind that high ZDDP and phosphorus is great for break-in but it is really hard on catalytic converters.
http://www.royalpurple.com/breakin-oil-rh.html

If you just want something cheap that you can pick up at your local store, then use an SAE 30 oil like Castrol HD 30, or some other similar brand.

I think that 10W-40 is a better year-round oil for our area, although 20W-50 would be good if you are racing your car. I also think that synthetic engine oil is a waste of money for a street car, but to each his own.

ericgrau

iTrader: (1)

Even on a piston you shouldn't break in with synthetic. You need a little friction to seat the seals and establish good compression and power. Any API certified dino oil should be fine. SAE scares me, especially for cold starts, but maybe it's ok if you baby it until it warms up. I mean 30 is 30 cold or hot; so if I understand right that SAE 30 is thicker than 20w50 when cold. It would also void the warranty on a new car because it's not API. You need to do the first oil change at 1500 miles as well IIRC from all that debris from the seals wearing in. 10w30 or 20w50 tend to be more pure than other weights; the wider temperature ranges come at the expense of more additives which means less actual oil.

Only in America do people still change their oil every 3k miles since 50 years ago. Even the Mazda owner's manual says 7.5k for dino oil. I figured out assuming the 2% mpg improvement various sites tested on Royal Purple and a reasonable oil change interval (not even double or triple as claimed for synthetics) that you break even on cost. So you might as well get it.

rarson

I seriously doubt you're going to see a significant difference in the wear during the break-in period between a quality conventional oil and a quality synthetic.

PvillKnight7

iTrader: (16)

Why do you want to spend money on oil that wont see hard use and will be thrown out after 500 miles?

J5sense

iTrader: (3)

anyone not worried about synthetic oil burning. when it is injected. its not designed for that, if mazda says it voids warrenty if you use it im sure its for a good reason. who knows what left over crap is on the rotors after it is burned.

86rx786

Yes and no. Mazda officially does not recommend the use of synthetic oils in rotary engines, however, long term and racing use has shown that the better synthetics (Redline, Amsoil, Neo, Royal Purple, Mobil1) are perfectly fine to use in a rotary engine, and will generally result in a 1 to 2% horsepower gain. However use of poor quality synthetics (like Valvoline, Castrol Syntec, Havoline, Etc) will result in build up due to high ash content left from these oils when they are burned. It is believed that is why Mazda did not recommend synthetics, because the couldn't pick favorites.

Chewbaccsw5

The Royal Purple is for later, its not for break-in. Im just saying I don't wanna use it yet until break in because it would be a waste. Im just asking what was recommended by you guys as a break-in product

Don49

iTrader: (3)

Valvoline Racing VR1 20w50. That is what was reccomended by my engine builder (Jesse Prather Motorsports ). You always want to use a conventional oil for break in. This is not new information. Anyone who tells you differently is uninformed. By the way, I have been building engines ( non-rotary) for more than 30 years and speak regularly with some of the top engine builders in the country.

dennis blackstone

synthetics will eat your oil seals....use the cheapest oil they oil come from the same refinary

i tore down an s4 t2 with 237,000miles bone stock and all i could find was rust in the water passages
other than that the seals was in spec

all the guy did was change his oil every 5000miles advance autoparts brand oil


all i put new was springs and side seals

86rx786

Icemark said that synthetics are ok for an engine as long as they are HIGH quality ones. Mazda doesn't recommend synthetics because they don't want to "pick favorites"