Ok. So today, I was having a discussion with our BG supplier at work ( I work at a Chevy dealership), and he mentioned that Mobil 1 is one of the best synthetics there is. We started talking about what we each thought the best NON-synthetic oil was (He kept pushing Supertech BTW, which I just thought was BIZARRE), But then he mentioned to me that I should run Mobil 1 Synthetic in my FC. I told him straight up, "Nah, I can't do that. Rotary engines are designed to burn oil." He says basically, "Right, but Mobil 1 is like the best, so it's ok to use in rotary engines." I pretty much disregarded this as non-knowing bullshit, but in the research I was doing just now on Supertech, I find THIS in the FAQ:

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.

So first of all: HOLY **** WTF??

Second of all: Has anyone here actually used Mobil 1? No adverse effects? Can I start using it in my 172K mile old FC? I frequently race this car on weekends in Autocross events...

 

Ok, heres the low down. Rotory engines cant really use synthetics due to the way they burn... they leave residue and such... Mobil 1 is the best in synthetics, thats well known, and you pay the price for it. But in all honesty, if your not running a BRAND NEW ENGINE, I.E. rebuilt/reconditioned, I personally dont, BUT I only use Mobil 1 conventional in my cars. (i had a vw 1.8t, castrol synthetic I lost HP under boost)

 

I, honestly, have never heard this, and I deal with it multiple times on a daily basis (Corvettes, Camaros and lots of rich bastards with money to blow...)

 

Rotary cannot use Synthetic is a Myth. a stupid one that is.

in fact, Mazda Japan sells Synthetic oil for Rotary engines. Its for Rx-8, but engine internals are 90%+ the same so I really don't see the reason it doesn't work. its a 5w30 PAO based oil(Group IV)

There was an issue with Mobil1 and old Rotary engine. but it was Mazda's fault. not Mobil1. Mazda updated the part and everything is good as new (it cost them a lot of money tho cuz they have to replace all engines effected by this issue)

I use Synthetic all the time, no issues.

if you want best Synthetic, you go Redline or Eneos, both use Ester (Group V) and best in the industry, far/much better than Mobil1. simply because most Mobil1 are not "REAL" Synthetic anymore. Thanks BP for that. (its a long story, google it)

Calling Mobil1 as the best Synthetic means this person don't know **** about oil. Its a brand that's known by most people. It has pretty good additive. but it is far from the best. (Even Royal Purple last longer than Mobil1)


Does it "worth" it to put Synthetic into a high mileage car? only you can answer that question

Did I do it to mine? yes I did. That's just me.

 

going back as much as 15 yrs i can say that i used nothing but castrol gtx in my 80 model with a 12A carbureted and the engine ran flawless all the way up until 120K when i got rear ended and the car totaled,cant go wrong with that brand

 

I'm not sure where I read, but basically unless its a new engine, it's pointless to use synthetic. Theres a rotory shop here, ill swing by there tomorrow and ask the guy. He's been building rotory engines for a LONNNGGG time...

and mobil 1 is the best

 

Another note, Synthetic or not. I will try to find and use older API rating than newer rating.

I try to use SL rated oil whenever possible. I hate the newer SM and the latest SN grade.

 

So first of all, the point of having a FAQ is to avoid answering the same question over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over, and over...

...with the SAME ANSWER that is quite plainly stated in the FAQ.




OK, so secondly, please ask your BG supplier how Mobil 1 can possibly be "one of the best synthetics there is" now that they have downgraded their formula to primarily use inferior Group III base stock, while nearly every other major brand primarily uses the superior Group IV and Group V base stock?

No, I am not impressed with Mobil avoiding the question, either.
http://www.mobiloil.com/USA-English/...Base_Oils.aspx

AFIK Supertech is Group III also.

It is usually not worth the money for a simple street/autocross application. It is more worth the money if the car is driven in a very harsh environment, such as endurance racing, high-rpm drag racing, extreme cold (Canada, Alaska, Montana, etc.), or extreme heat.

 

15w-40 rotella t ^_^

 

Here you go Rotary synthetic: http://www.idemitsu-usa.com/page_207.htm

BTW if I remember correctly Mazdaspeed former MazdaComp USA recommended the use of synthetics.

 

Use high quality synthetic oil. Last time, I read somewhere that Mobil 1 doesn't work to well in a Rotary engines. Too lazy to search. But I do know that Idemitsu, Mazda Japan Synthetic, Redline, and Royal Purple work very well. Its been proven long term. I personally use Royal Purple because its easy to get and is cheaper than the other ones I listed. I've used royal purple for 8 years, none of my rotary engines have lost compression or blow an apex seal. If you want to have the best setup or if you are scared, then do premix.

 

damn i just made myfirst oil change in my car with mobil 1....guess i'l have to try some of these other brands

 

Mazda Usa sends us Castrol GTX 5-w20 conventional at our shop ( I work as a Mazda Tech) My only speculation to this whole discussion is in racing applications where combustion temps are high enough to burn off residual oil from a synthetic based oil. But in a daily driver joe-blow driven car I wouldn't think it'd be a good idea.

Honestly to each their own, and do as you like. Warranty or customer pay, i'm still making good money from doing Rx8 engines hahah.

 

wrong, they're doing it because that's what they "recommend" in their manual. and stop spreading that "oh compbustion temps are not high enough yada yada" bs.

if Synthetic is really "all that bad", then explain to me why they're selling synthetic oil in Japan?

and their recommendation is not even always right, 5w20, last I know they recommend 5w30 for FE for the rest of the world, and for older rotary engine they recommend all kinds of oil, even has a graph to show you. but I guess people are too freaking dumb these days to think on their own, perfect ! so Mazda(any other company) just recommend 5w20, at least its easier to meet CAFE rating with it.

ohhh one more thing, to make 5w20 possible you have to have to synthetic stock in it. so how is Synthetic bad for rotary ?

 

Mobil1 won't kill you, their 15w50, 0w30, and 0w40 are actually ok.

if I want Synthetic (real and that's worth the money), then I will only get Eneos, Amsoil, Redline, or Royal Purple.

 

Yeah, I know, I've referred to the FAQ on several occasions and read through it twice myself. How I've missed this so far is completely beyond me.

The reason he said it was the best was because their sulfer content has always been between 250 and 270 PPM, and they test and verify that on EVERY batch.

So what would be the best oil to run in this car that is mainly a cruiser with occasional races (maybe 1-2 a month)?

 

regular conventional mineral oil, 10w30 or higher preferably 20w-50
I personally use valvoline vr1 sae 50 in the summer, and 10-30 when it gets below 40F
This is on all my rotaries, turbo and n/a

 

If you go to the BG website (if they still have it on there) they show anti-friction tests with several different brands of oils and Mobile 1 being one of them fails at a low torque rating vs. other synthetics. I saw a BG supplier perform (at the delearship where i work) the test with the which resulted in Mobile failing at a lower rating then pennzoil conventional.

 

Oil temps will be lower using Mobil One. Been there done that test. Same day, same car. Just changed the oil to Mobil One and looked at the oil temp gauge to compare.

Add that to your faq. ha

 

How does that matter?

I think Castrol GTX is the best bang for the buck for rotary engines. If you like synthetic oil, then I would recommend one made with Group IV and/or Group V base stock, such as Red Line, Amsoil, Idemitsu, etc.

Was this test done with the old Mobil 1 that was primarily Group IV, or the new Mobil 1 that is primarily Group III? If it was the new Group III, then did you test the temperatures with any actual synthetic oil?

It will work just fine, and Group III does have better shear and wear properties than Group II. It's just not really worth the money in my opinion. Nearly every car owner on this forum would be just fine with regular petroleum oil, but if there is some reason why you would want synthetic then actual synthetic oil would be better. Just DO NOT put Mobil 1 gear oil in your RX-7's transmission, as it will eat the synchros.

 

I did not put mobil 1 in. i put in royal purple.

Do you guys buy your oil online or local? I dont think I can get any of those group 4 oils from pepboys...its mostly cheaper stuff with mobil 1 and royal purple being the high end stuff.

 

castrol ftw

 

Royal Purple is mostly Group IV, so it is considered a true synthetic oil.

Since I do not race professionally, I consider synthetic engine oil a waste of money. However, I do like synthetic oil in the transmission and differential because I can feel and hear the difference, and the extra cost isn't so bad because the gear oil has a 30,000 mile change interval. I buy Red Line MT-90 and 75W90 online, usually from Summit Racing, Jeg's, Pegasus, or Racer Parts Wholesale, depending on who has it for the lowest price.

 

Thank you for the insight. This car is my DD so for a few extra bucks and peace of mind is enough for me to put in synthetic. Now that I know mobil 1 isn't one of the better brands I will definitely be getting a higher grade oil.

 

Agreed!!!!