I switched to motul 300v racing oil ( I don't have a OMP ), and after I did, I saw multiple people saying not to use the oil on a car that doesn't go on the track, because its not what the oil was made for ( Something about it leaving carbon... and race engines being opened and cleaned regularly...blah blah blah..) I drive my car sportly, wait for it to warm up, etc... Is there such a thing regarding this oil? Or is it just what people say just cause they can?

 

A very simple search:

https://www.rx7club.com/search.php?d...y=Motul%20300V

 

Oils have different additive packages depending on use cases and manufacturers. I don't remember the types of additives between street and race but you can probably google for that if you want to learn. Racing oils generally aren't designed to be run as many miles as street oils are for example or in cars with catalytic converters.

Considering most of us have short oil change intervals, it might not be an issue but ymmv. Ultimately, oil is oil. So long as it's oily and clean, it will do the job.

 

Thanks for your reply. I want to change the oil every 1000 - 2000 km. I don't have a cat, and can't stop myself from punching it constantly. I was also looking at valvoline vr1 synthetic. I want to get a synth oil since I don't have a OMP, so I don't care about mineral. I had idemitsu, but wanted to try something new. Seen people say that after 500km s 300v isn't protecting as much as it should. Should I just switch to idemitsu again instead of a fancy oil ( IK idemitsu is sorta fancy as well )

 

Wow, 1-2k km?! That is an obsessively short oil change interval

Which brand and syn vs conventional is up to you. Do your research and use whatever you are comfortable with. Suggest you have a look at https://bobistheoilguy.com/forums/ as there is some good info on there. Ultimately, unless anyone is having their oil tested, they are just making educated (or uneducated) guesses about how well an oil is doing in their car.

 

+1 gracer7-rx7 explanation

Longtime (approaching 10 years) 300v user for track prepped street car. Motorsports cat, moderate-heavy pre-mix ratio, regular oil changes (dependent on DE's per year), etc. Other than being expensive I've got no complaints. I personally really appreciate how Motul reformulated their product in an effort to be more environmentally conscious and also worth mentioning that it's ester based just like the old Mazdaspeed Rotary 1.

https://bobistheoilguy.com/forums/th...gine-oil.5158/

A little research will go a long way and there's no shortage of brands to choose from. I hope this was helpful.

 

A minor note, but IIRC the Mazdaspeed/Idemitsu oil was PAO based, not ester based. I haven't read the paper in a while but I think ester formulations were rejected as the deposits left after flashing off of the apex seal flanks were significant, and reducing said buildup was the impetus for developing a rotary specific oil. Zinc based EP additives (ZDDP) were also eschewed for the same reason.

 

Thanks, awesome info. I don't use the OMP, and premix using premix (Although still idemitsu, I've heard and seen that it's great), so I don't really mind about apex seal build up.

 

I have not heard of 300V breaking down and not protecting as well after such low miles. Used Oil Analysis (UOA) would be a definitive answer to prove that, yet I have not seen any UOAs that do.

 

I think it's awesome when there are oil discussions that actually contain information, rather than people just shouting what they use with no information behind the reasoning nor consideration that each usage type would require different considerations. We need to normalize the notion that there is no one-size-fits-all answer to this question. What works for one person, may not work for others. I'm certainly no expert, so take my findings with a grain of salt, but here's my .02

I believe ninesixtwo is correct on the MS/Idemitsu being PAO based. The way I read the post linked above would confirm that:



One thing I do like about the Idemitsu oil is the Moly additive. I don't know if this is more beneficial in rotary engines vs other additives, but we use Moly a ton in my industry, so I'm familiar with its benefits as a whole.

The TDS on Motul's website is a bit sparce on information, but one thing that gives me pause when considering it would be the flashpoint. It is a bit lower than flashpoints of other commonly recommended rotary oils (particularly Idemitsu/Renewable Lubricants, but it should be noted that it is very similar to Amsoil, and noted that VR-1 does not include flashpoint in their TDS).

Another thing I would be interested in seeing is the Sulfide Ash %. My research into the topic has lead me to believe that having a low ash oil is one of the more important things to consider when looking at oil for rotaries. Even more so than Zinc (ZDDP), because rotaries don't have valves and other things that really like the zinc additives. But again, the TDS of oils are all over the place with what they include. I think only Renewable Lubricants and VR-1 are the only two I've run into which list the Sulfide Ash % (coincidentally, both those oils are listed as having <1%).

300V being ester based is also an interesting topic to discuss. It sounds like a good think in theory, but I'm reminded of some issues people had brought up about ester based premixes in the past. There were many instances of those premixes leaving a white residue on engine intake/housings/rotors. Now, truth be told, no one could ever come up with an actual reason that residue was 'bad'. But most agreed they just didn't like it, and would stay away from those premixes. I'd be curious if the Motul left a similar residue on the internals of the engine. Again, I have no evidence to suggest you should stay away from it, even if it does leave the film, but it would be something to consider.

Speaking of premix, I know that Idemitsu is a very commonly recommended premix for our cars, but I would suggest looking into some of the independent test some have conducted on how well it stays suspended in fuels. I have seen a couple that would indicate that it can begin to separate in as little as a day or so. Based on those results I have switched away from it for one that looks to stay suspended for longer intervals (my car is not a daily driver, so I feel this is an important factor in my choice of premix). Also, even though I'm not on E85, we (here in the states) can have up to 10% ethanol in regular pump gas. So, drilling down into the premix choices, I've chosen on that the manufacturer says is compatible with both fuels. [Though, if you are in an area where there is no ethanol added to regular gas, this MAY not be an issue. I suspect that this may be a contributing factor in Idemitsu not staying suspended in American fuels]

All this to say, I think you may be wasting a bit of money on the Motul and such short oil change intervals....but I don't think Motul or short change intervals will be harmful to your engine.

 

@REnaissance_Sle7in

At the risk of taking this thread a little off topic....
I also have some concerns about the separation as well as observed in an RX8 race car I have. It tends to sit for long periods. What premix did you switch to?
And some research / testing from another forum member on the topic (albeit) with e85:
https://www.rx7club.com/build-thread.../#post12452250

 

I was hesitant to add that part for fear of derailing as well, but the OP had mentioned premix and no OMP, so I figured it can't hurt to include that bit.

Personally, I chose to switch to Renewable Lubricants premix. The main attraction to it is the manufactures statement that it is able to be used with both regular gas and ethanol fuel. Since we have a percentage of ethanol in all of our regular gas, I figured this was a beneficial property of this lube. Plus, while I'm strictly pump gas at the moment, I do have a flex fuel sensor on the car, and eventually will tune for E85 as well. With that, I don't want to be agonizing over premix and worrying about them playing well with each other in the tank when I mix fuel or there is no E85 available. I also saw a teardown of an engine that strictly used RL from rebuild to teardown, and the results looked good [RadPotential youtube]. Now, would I recommend it? Not necessarily. It is still a very new product in the grand scheme of things, and the case study I saw on it was very brief (only about a season of driving), so IMO long-term testing has not been done to say definitively that I would personally endorse it to others. But, it was enough for me to switch on my own car (plus, it smells real nice).

As with the "which oil should I use" question, I really think we also need to better explain to new people that there is no single answer to the premix question either. It is a hugely nuanced subject, and we need to stop parroting the old Racing Beat ratio recommendations from like 30 years ago. SOOO much has changed since then. That particular post from Carlos illustrates one of the most underdiscussed factors in choosing premix and ratios (IMO): apex seal manufacturer ratio recommendations. But, I'm digressing. That's a subject for another thread.

 

Thanks for the info. I will continue using 300v, and will also look into renewable lubricants premix since I want to use meth injection in the future.

 

I have used the 300V for years and i never had a single issue but at the same time i have also used different oils that served me very well. I dont see the need for this expensive “exotic” oil . I believe that keeping the oil temps low will benefit you no matter which oil you decide to to with.



I used a variety of premixes and the 300V with good success . Seeing from your location, i am assuming you are in Romania and the available options are not the same as you would find in the states.


as i am also from Europe i have the same issue. Ii have however found a two stroke oil that has served me very well for a very long time and it is available pretty much everywhere in europe. mobil1 racing 2t is a great option that you can find anywhere and it is not expensive

 

Jim Mederer, explained this at one of the open houses Racing Beat used to have. He says Delta T, which is basically the temperature difference. if the oil INTO the engine is cool, it can pull more heat OUT.
the oil has two jobs in a rotary, cooling the rotor, and the seals in the rotor are just as important as lubricating the bearings.

so i agree, at full power oil temps want to be relatively low into the engine.