Left a bunch of milky residue all inside my filler neck. It also suffered horrible fuel dillution and was thin as water within 2k miles. I switched and within 2 oil changes the milky residue was gone (took some time to get it out of the oil cooler I guess).

 

My old man and I have experienced residue in Mercedes vehicles. However, the ones we have used have not had a pcv valve, but a pcv orfice (it's strange and German, don't ask). Upon switching to a synthetic the residue problem went away. It was almost like a condensation building up on the oil.

 

I think you are wasting far too much time and effort on this topic. Honestly, I can't think of anyone who's experienced oil-related damage in over 4 years here. Any synthetic will do the job just fine.

As far as the "milky residue" goes, that is due to condensation and has NOTHING to do with the type/brand of oil in the car. I've had that residue with different weights, brands, dino and synthetic. And as oil breaks down and/or becomes contaminated, it will get sludgier, not "like water". By that reasoning, the Castrol held up the best!

 

Confirming what rynberg said. That just sounds like water condensation and not related to brand or type of oil. Likewise the fuel dilution, due to leaking injectors or running too rich for whatever reason.

Larz, I'm still not exactly sure what type of info your looking for, but FWIW:


http://www.realclassic.co.uk/techfiles/oil030319.html
http://www.mobiloil.com/USA-English/...rade_Oils.aspx
http://www.bobistheoilguy.com/

 

I use amsoil in the engine tranny and rearend with very good result over previous oils used.(Valvoline, redline, royal purple and Mobil 1) I would say that mobil 1 would be my 2nd choice for motor oils and redline for gear boxes.

 

Waste of time? Maybe. But if everything was exactly the same, it would not matter what we bought. I have gathered a bit of information about filters and ascertained which of them is worth the money and why. I was hoping that somebody was an engineer or had some other technical background and would be able to give an answer backed up by facts. While it is interesting to see the man that built the 787 say Mobil 1 is bad, there was no reason behind it. That is what I seek.

 

How do you know if the viscosity was degraded? Unfortunately, no oil is going to look as thick as it did when you poured it out of the bottle into your engine (short of running it until the sludge deposits are high enough that it does "appear" like viscosity hasn't changed, and by that time you've got plenty of other potential problems).

 

Well then, I guess what I should have said was this oil looked noticably thinner at 2k than any of the other oil Ive used.

 

Even if he did state the "reason behind it", that information will more than likely have no bearing on what makes a good performance motor oil for a gasoline-powered automobile. The oils that are used in turbofan jet engines are not the same as those used in gasoline engines, and their requirements are totally different. The aircraft engineer who may have said this will have his own reasons for not liking Mobil 1, but that has absolutely no bearing on the company's auto oils.

Each particular oil may eke out a small advantage over another in one particular area of performance, but unless you've had a blend made specifically for your application by a manufacturer (and I mean truthfully, not marketing adspeak...), you will always be making compromises in one area or another. There's only so much additives you can put into a base stock; motor oil is like a barrel, you only have room enough for the base stock and a certain amount of additives.

The question "What is the best synthetic motor oil?"-- even for rotaries-- is much too general within the vast scope of motor oil performance to have any type of answer.

 

Sorry, no offense, but you're not going to be able to gauge an oil's viscosity by how it "looks".

 

Especially when you consider that very few - if any - so-called synthetic oils on the market today are truly synthetic. Kento, I'm sure you remember this thread: https://www.rx7club.com/3rd-generation-specific-1993-2002-16/well-its-been-while-since-weve-had-good-dino-vs-synthetic-thread-218255/ Others, I'd def. take a quick look at it. The first post alone will show you how deep - end essentially pointless this discussion really is. Why? Because as Rynberg said, we have yet to hear of an oil-related failure. Heck, Wargasm drove his car for 54,000 miles w/o changing the oil ONCE! https://www.rx7club.com/showthread.php?t=309812 And I'm sure a bunch of us have parents with cars that never get the oil changed until we get around to doing it for 'em every 10K - 15K miles And those cars are in the 100+ (if not 200+) thousand mile range...still alive and kickin. So why all the fuss??

~Ramy

PS: I must say, advertising is really effective. I've been a hardcore Castrol fan ever since that commercial where they left the motors running after draining the oil And now Mobil-1 has this commercial about extended drain interval oil they came out with. Ironically, Amsoil has recommended 25,000 mile/one year drain intervals since 1972... (Mobil dropped that recommendation back in 1974, but it seems they're finally coming full circle...)

PPS: Rich, I'm prob. gonna be rocking Idemitsu when my car's finally finished. It just "feels" right LOL

 

mobile one,walmart is real close to my house.

 

Im about to purchase idemitsu oil but they recommend 10w-30 for all motor and 20w-50 for turbo apps, it wouldnt be a problem to just use 10w-30 anyway right? I mean it is approaching summer, i want to be problem free.

 

http://www.royalpurple.com/techrp/ncsu021112.pdf

 

That paper only compares Royal Purple against Havoline and Kendall (dino oils). It doesn't compare a synthetic to a synthetic.

Dave

 

Actually, the three oils compared were Shell Rotella, Amsoil, and Royal Purple (all synthetics, if I'm not mistaken), in 15W-40 viscosity.

However, that test isn't really that conclusive, because even though the test engines (a diesel and gasoline engine) were spec'ed out and built with "as new" bearings and other components, you still have production tolerances that continue to wear in and affect frictional losses as the engine is run. Also, there was no info on how the oil was changed between brands, and there were just two tests run at 1200 and 1600 rpm.

 

Learn more than you ever want to know here:

http://theoildrop.server101.com/ubb/...?ubb=forum;f=1

:-) neil

PS: IMHO, due to how rich our engines run (esp. if NOT stock), our oil gets contaminated very quickly, hence the cycle of 3000-4000K miles changes, irregardless of synthetic or not.

BTW: I think I'm going to move to a diesel-rated synthetic (e.g., Mobil Delvac 1) since it holds so many things in suspension

 

All gasoline engine motor oils have dispersant additives to keep particulates in suspension. Choosing diesel motor oil simply because of that aspect is not seeing the forest through the trees. Keep in mind that diesel engines don't reach the internal engine temps and rpms that a typical small-displacement (much less a turbocharged Wankel rotary) gasoline engine will. The combustion by-products are totally different as well, so the additive packages differ greatly. A diesel and gasoline engine have different needs from their motor oil.

 

I would not recommend diesel synth oil ...not the same formula.....

Also, the thing about filters is: how do they stand up to the gas in the oil?....especially in a rich running rotary? I have not searched, but after reading this thread it was the first question I thought of. I have used Mazda OEM filters a lot, but in a pinch have used the FRAM tough guard 3593's....

Royal Purple or Idemitsu are the best synths IMHO...but I like Castrol GTX regular oil when changing a lot since it is SO much cheaper to use. IF racing though....Synth all the way....

My last TII went 170k on ORIGINAL ENGINE before I traded on an FD and it was still over 100psi per chamber...and high steady oil pressure...
I used Castrol GTX 10w30 for winter and 20/50 summer. Stock OMP system....and Mazda or FRAM 3593TG oil filters....

NOT sure how scientific this is...but I suggest this tip: Clean the oil dipstick really good and when checking the oil level LOOK to see if the oil is sticking to it evenly (making a good oil film....check at every gas fill up)...IF it is not sticking to the METAL dip-stick, then it is not likely to be sticking to the bearings with a good film of oil either...also check for gas smell....IF so...CHANGE your oil and filter.

Also, IF you smell gas in the oil (most likely after boosting heavily for extended periods )....change it....

 

idemitsu

 

I will never change oil. It will always be Mobil 1.

 

Wow...you must have $$$! You're the second one I know that uses it. And I thought my Royal Purple was expensive.

 

Please, someone show me something that says"my oil destroyed my engine", and prove it. I'm not proud of it but I just changed the oil on my John Deere lawn tractor, 7 years after I bought it. It was lumpy lookin **** but the tractor does'nt use any oil and still has good compression. Just never got around to it cause I was busy with other stuff.

 

I use the Idemitsu 10w30 synthetic oil supposedly designed for a rotary engine. Supposedly it burns clean, what the call ashless. On top of that I also use the Idemitsu fuel lube. 1 gallon of fuel to 1/2 ounce of fuel lube oil

http://www.mazdatrix.com/q-supply.htm

 

I use Idemitsu also. A little bit more expensive but anything that helps keep my engine running is cheap insurance. Quite a few other oils seem to be good but idemitsu is used by Jesus Padilla (Kilo Racing), Ari Yallon(RX7.com), etc. and that is good testimony for me.