Well im a newbie here as can be seen.....so naturally i have a simple question. I have been looking for a decent 3rd gen to buy and think i have found one but the owner has claimed to have run synthetic oil through the motor. The motor only has 30 k miles on it should i be worried?

 

Nah. Is that 30k original?

 

This is a debate that has gone on in countless threads on this forum. My brother runs synthetic in his car and so far no problems. Nearly 60K miles on it. I have run dino oil and no problems,11K miles on the engine. Most shops (Tri Point, M2, etc.) sell synthetic oil, mainly Red Line.

Some people will tell you it will kill youe engine and some say it is the only thing to run. Both groups make good arguments. I don't know what is best. Be prepared for a lot of opposing opinions.

Sorry I couldn't actually help answer your question.

 

It's better for your engine and more harmful to your wallet. If you aren't planning on rebuilding your own engine, then go with fossil oil.

 

I had no clue synthetic oil could be bad....? I thought it was good for high performance engines....

 

My friend and I just rebuilt a 13b for a second gen owner who has used nothing but synthetic oil. When we opened the motor up, we noticed two very distinct detrimental effects of synthetic oil. First, the rotors had synthetic deposits built on them. As you know, synthetic oil doesn't burn, so it leaves a goo like substance behind. This is the same substance on the rotor. Second thing the synthetic oil did to the motor, it literally destroyed the o-rings. When we took it apart, the o-ring was so brittle that it nearly fell apart when we tried taking it off.

Now of course there are also pros to using synthetic oil. Main reason, I run it is because it keeps the oil temperatures lower than dino oil, but at the same time I do not daily drive my car nor expect the motor to last 100,000 miles. If you go to Japan, everyone there is running full synthetic oil in their FD's, but then again, they don't expect the motor to last more than 30,000-40,000 miles. If you are using yoru car for commuting, maybe you should consider just going to mineral oil, if you are into heavy racing, you should switch to synthetic oil.

 

its is good damnit!!!!!!!!!! that turbocharger on your fd NEEEEEEEEEEEEEEEEEEEEEEEEEDS it!!!!!!!!!!! use a high quality synthetic. . . period. youll never turn back. it runs so much cleaner. it makes a difference. . . trust me. . . and about 8 bagillion other rotary engine powered vehicle owners.

paul

 

I think this makes a lot of sense. We can all speculate and guess about this topic until kingdom come, but there is no substitute for getting inside the engine and physically examing it. I would like to know how many miles were on the engine and what the wear is compared to spec - have you measured it at all?
I would especially be interested in the rotor bearings.

On a side note, Mazda used a special synthetic oil made just for them in the 91 LeMans Racer which of course won big time. After teardown the Mazda engineers were amazed how little wear took place. It was about $25.00 a QUART, and you can still buy it! Me? - straight 30W dino, but I live in a warm climate and change it about every 1500 miles or so.

 

thanks for the quick replies.........still kind of torn though i think i will persue the car anyways.

 

In general, synthetics burn just like mineral (conventional, dyno, whatever) oils do. But certainly there are some that burn cleaner than others in both categories. What kind of synthetic was the owner of the dirty engine running?

There may also be other causes of the apparent problems with that engine. Overheating is likely to harden the o-rings, for instance. It wasn't necessarily the oil that led to the problems you witnessed, though it does seem likely with the deposits. Oil additives, crappy fuel, or an overly rich mixture might contribute to deposits as well.

Lots of people have used synthetic in rotaries for a long time. I wouldn't steer away from buying the car because of sythetic oil. It may even be indicative of a higher-than-normal attention to caring for the car.

-Max

 

Screw it .........if you live in Boca you can afford a rebuild even if it DOES blow.......

David

 

Just get good synthetic, I run redline, its some good ****!!!

 

search.

 

what is dino oil? Also, why do people change to say 15-50 then to maybe a 10-30? whats the reason for that?

 

Dino is latin for "terrible". When referring to oil it means that it was refined from fossil oil that was pumped from the ground.

 

yeah.. which is better for my 20K engine, 10-30 is better right?

 

If I remember correctly, the 15 is for cold starts and the 50 is for extended high temperature periods. 10W-30 is like a med/all purpose comprimise, so to speak.

I was using 10W-30 dyno and mixed 1qt race 50 Royal Purple every 1k. Then I researched the oils and Penzoil is dirtier than Royal Purple, Red Line and Mobil 1.

Now I have decided on 10w-30 & 1qt race 50 RP for summer and 5W-30 & 1qt Race50 for winter. Oh and I spend the extra money on Mobil 1 filter and sometimes substitue Mobil 1 from Costco.

Click below for Mazdatrix's explenation:
http://www.mazdatrix.com/faq/synthetc.htm

 

I agree with both sides and see how synthetic can be better, however in the owners manual that came with the car (written by mazda, the people that designed the car) it specificly says not to use synthetics. So until Mazda releases a statement saying the new sythetics are okay, I am going to stick with fossil.

Just my .02 cents

-Charlie

 

Mobil 1 15w-50, Redline, or Amsoil....only way to fly....period

the critics of synthetics don't have a leg to stand on, and I believe Mazda recently debunked the whole synthetics in rotaries myth anyway....I'd be very surprised if the RX-8 has any warnings against using it, if anything, synthetics burn cleaner (very low ash)

like max said, regarding the guy who tore down his engine and found "deposits", that could have happened for any number of reasons, including using crap oil in the past, not changing the air/fuel filter, crap gas, etc, etc, etc

synthetic oil rocks, the skeptics are wrong....in a high revving, extremely high temperature turbo engine like the 13B, not using a synthetic is pretty dumb if you ask me, I'll never go back to dino juice

 

Synths have evolved considerably since Mazda "banned' them in their rotary engine. One of Royal Purple's head techs races rotaries and uses RP in his own engines. I've used synth in my car since I've owned it (purchased at 9600 miles) and I'm now at 55K running 13psi daily, stock engine stock turbos, producing about 330-340rwhp (for about 1.5 years now). I'm pretty sure synth has done more to help it stay together than tear it to pieces :-)
Michel

 

Oh yeah, here's a link to some Royal Purple info

https://www.rx7club.com/forum/showth...t=royal+purple

 

just drop this damn discussion. there will never be an end to it. i recommend that the moderators delete any thread that opens up another conversation like this. the key is that everyone has THEIR own reasons. so LET them HAVE their own decisions. LEAVE IT ALONE!!!!!!! this is the most disgusting topic i have come across on the forum.

paul

 

Mazda did release a statement....

 

I checked with both amsoil and mobile 1 and they both said that while mazda doesn't recommend sunthetic, they have done extensive testing with the rotary engine and have had great results.

 

quote:
--------------------------------------------------------------------------------
Originally posted by charliegt
I agree with both sides and see how synthetic can be better, however in the owners manual that came with the car (written by mazda, the people that designed the car) it specificly says not to use synthetics. So until Mazda releases a statement saying the new sythetics are okay, I am going to stick with fossil.

Just my .02 cents

-Charlie


...which was published, where....?