Well I guess you can choose your oil in one of two ways...

You can have "feelings" about your oil or you can go by the numbers.

 

You are mistaken, the graph shows great differences in oil cST at 0 deg. Look again, graphs can visually seem to show one thing, when in reality they do not show that at all.. at 40, there are still differences, but it's not possible to see the differences on this graph..

 

^^What he said, anyone who looks at that graph and can't see the huge difference even from 0* upwards wants to learn how to a) read a graph, and b) scale a graph so appropriate data is shown.

 

The simple method of choosing an oil comes down to two major aspects:

Choosing the operational weight of your oil is going to depend on how you use your RX8. Track use is going to require a different weight than daily driving. Regardless of what operational weight you choose, get the oil which provides the lowest viscosity at 40 degrees to ensure the best protection from statup to operational temperatures. A 10w-40 and a 0w-40 both provide the same viscosity at operational temperature so why not use an oil that is the thinnest in that range when cold?

The second aspect is the type or group base oil that you use. If you tend to change your oil in frequent intervals then you can easily use a mineral oil as the additive packages and viscosity index improvers won't have totally worn out. If you tend to go longer intervals (past 3,000 miles) or simply are looking for added protection then use a true synthetic oil which is a Group IV or Group V base stock. The costs are higher but the oil will provide protection longer.

Oil continues to remain a personal choice. Some people choose their oil based on how it makes the car feel, how the label looks or even by the fact that expensive oils make people feel like they are driving a race car...who knows. Every brand claims to be the best.

Other ways to choose your oil are to be objective about your use, understand that while the manufacturer suggestions are motivated by warranty concerns, political and environmental regulations, that engine designers plan ahead for what oil weight and type will be used in their engine. If designing an engine was easy we would all be making our own.

Educate yourself on the various aspects of oils you believe are good and if you have doubts spend the $20 or $40 on a couple of oil tests to determine if the oil is good for your motor.

 

Dr Hass in his article stressed that Racing Only Oils are not recommended for street use because those Racing oils do not have detergents.

Also event 0W-30 is very thick for our engines at cold start up WHY makings thinks worse with 10W-30 ?

If you think that 0W-30 and 10W-30 have the same characteristics and they cause the same wear, why people bother by making two products? If the difference is very small what is the reason of making 0W-30 or 5W-30 or 10W-30?

I do not think that the reason is finland and icy conditions

 

Most really cold countries use pre-heaters on the oil pans anyway...

 

+10000

THIS IS MY POINT , This is what I am trying to stress to people here BUT their only argument is that 0W-30 and 10W-30 ARE SIMILAR. WRONG THEY ARE NOT SIMILAR.


0W-30 will have less wearing at cold start up and will protect the same at operational temp as 10W-30 WHY NOT TO CHOOSE ????? I guess I will hear again about Idemitsu which is rotary specific and was used in Le mans (well the streets are no Le mans)

 

One thing to keep in mind is that race teams do not use the same formulations that are used for street oils. While a specific race team might use Mobile 1 oil, the additive packages and formulations are specific to that race team. You cannot get the same oil that F1 teams use in their cars and honestly you wouldn't want it.

Oil companies will sometimes use a "Race" label as a means of attracting sports car owners because the thinking is that if it's good enough for a race car then it's good enough for my car.

True race oils are not meant for street use. They don't contain detergents and are designed for engines which are torn down and rebuilt on a frequent basis.

The other mistake that is made is thinking you need a winter and summer oil. The truth is you don't need to change oils with the seasons. Your winter oil will work fine for the summer. Using a thinner oil in winter doesn't make any sense because your engine still runs at the same operational temperatures. Unless you are seeing major differences in your oil temperatures during the summer there's no reason to change.

However, if you see major differences then you have a cooling problem and not an oiling problem.

 

^ So Flashwing you are saying that Idemitsu is not RACING ONLY OIL. It is also for street use. Correct?

If Idemitsu was Racing Only Oil we would have problems or difficulties to get it or would not be commercially sold at the stores etc

 

The rates and the cst numbers are wrong in that graph. Even in Celsius but mainly if the temps are in Fahrenheit as it's shown.

 

mobil1 0w20? they have 3 versions, synthetic, advance fuel economy, and race version.

http://www.amazon.com/Mobil-Syntheti...0002350&sr=1-1

https://www.mobiloil.com/USA-English...l_1_0W-20.aspx

https://www.mobiloil.com/USA-English...ing_0W-20.aspx

for some reason i couldnt find the regular 0w20 synthetic on their website...maybe the advanced fuel economy replaced it?

 

Well, I figured the best way to get the straight up answers on IDEMITSU RACING OIL is to ask the company itself. Scott Shiotsu is the representative I contacted at Idemitsu USA and I asked him for clarification about the two oils that they make for rotary engines, a 10W-30 and a 20W-50. So to lay to rest all the speculation that's been going on in this thread he gave me permission to publish what is below. I made up the questions, he supplied the answers....

 

Spin, first thanks for taking the time to contact Idemitsu regarding these issues. This certainly is more information than they publish in other areas but some of it is still a little vague. Not saying that's a bad thing but I'm always in favor of having more information instead of less.

By how I read these answers, the Idemitsu oil isn't a "Race only" oil which some manufacturers do provide. Valvoline provides a Race Only version of their VR1 oil which contains little to no detergents but also has a change interval of 500 miles.

In this case it sounds like the "Race" title has more to do with marketing than it does with the specific formulation. While some elements of the oil (perhaps the base stock) is the same as the oil used in the 787B the true additive package and what not are going to be based for a street/race application.

I'm glad to see that they provided a bit more information about why the oil is considered good for the rotary engine. Royal Purple advertises itself as rotary engine safe but doesn't say WHY it's safe for rotary engines.

Now, the question becomes on whether or not you need Idemitsu's oil or if it provides any benefits beyond a good synthetic for an individual's driving needs. Idemitsu's oil could be a good choice for those people who use their car for both daily/street driving and some track use like autocross or even some moderate road racing without having to switch oils.

 

You're welcome Flashwing...always go to the source Well, concepts like "an individual's needs" and "beyond a good synthetic" may be key here, but I think Itemitsu has made the oil as rotary friendly as possible, which can't be a bad thing. Who else has bothered to actually put the word "Rotary" on their oil can and sell it in the USA? The market is not that big, so it shows a serious dedication to the rotary community, if nothing else, and certainly doesn't make big profit leader for a company as huge as Idemitsu

Anyway, it might be interesting, but I'll leave writing to competing synthetic oil companies to ask how rotary friendly they are to others. I'd guess none of the others, with the possible exception of RP, will have anything to say on the needs of rotary engine and their oil formulations. To reiterate what Idemitsu says

Performance is hard to quantify, but I can give you one clear benefit I've discovered. I have no tailpipe soot - simply no thick black sooty coating to take off with metal pollish, no grunge to wipe off back there at all. Normal daily driving would quickly turn the tailpipes black black, and now there's virtually none - that alone is totally amazing to me after 5 years of having to use strong metal polish on my tailpipes constantly!

To show what I mean, I've driven around for a couple weeks since the last car wash exercise, so just now I took a paper towel and wiped both tailpipes all the way around with it. Before using dino oil, this would be so black it was nasty....now this is the result. They'll stay this way, and next wash time I'll simply rinse them w/a bit of soap and water and they'll shine!

 

i think Idemitsu provides the OEM oils for Mazda in Japan, and for other japanese car companies. Im not sure if that goes for other countries, like the US.

 

In my experience with oils and the rotary, the only synthetic oil I would ever use is Idemitsu. I cannot stress enough why it is the only synthetic you should ever use in a rotary. in other words, dont use a synthetic unless it is Idemitsu.

Collectively, myself and a few others have tested this out. snythetic oils tend to ruin the side and apex seals. also on the 4 different race cars, Idemitsu is the only synthetic that a bearing did not seize on the crank.

Now having said that, the 4 different race cars were not "renesis" 13b's, the were the rx7 13b's. in all different forms too. 2 rotor, 3 rotor, bridge port, etc.....
12,000 rpm drag race engines to be more specific.

 

I wish for a 0W-30 Idemitsu oil !!!! too bad there is only 10W-30

 

Idemitsu have a lot of oil grades in Japan.

oh well

 

I know I will get Flamed here but,,,,,

IDEMITSU is just another Oil and Petroleum (gas/petrol) company in Japan, like Shell, Mobil/Exxon, BP (British Petroleum, CASTROL), etc, etc.

Yes they market oils too, and YES Idemitsu oils were used in the Winning Mazda 787B in Le-Manns..so what!..

There are equally just as many Engine Oils, Brake Fluid, 2 Stroke Oils made by other Petroleum Companies that are just as good and much cheaper..

Don't let the "romance" of this brand get to you...

 

The problem is that a street driven car has much different oil needs than a race car. The amount of abuse a street car is going to take might not be as severe as a race motor but the abuse is done over 100k miles as opposed to the couple thousand a race motor would see before a rebuild.

Ash I completely agree with you here. What still bothers me is Idemitsu claims that their oil is developed for the rotary engine but doesn't say why it's superior over other motor oils. I don't like the "trust us" kind of message that I get from some companies.

I admit I use Idemitsu pre-mix in my RX8 and I have because several people I trust use it so I'm certainly not against their products.

In terms of the oil used in the 787b I can tell you that much of the aspects of that oil are not going to be used in a street application because the needs of the motors are going to be totally different. Race motors are looking for lots of protection for a short period of time and promote efficiency at the expense of longevity.

The race motor doesn't need to last 100,000 miles. It just needs to make it through the race.

 

How very true mate.

 

What other oils did you test? Did you ever use redline oil?

 

Check my used oil analysis thread for the results of different oils. Idemitsu is no better than any other good synthetic. Not to mention it comes in shitty bottles that leak easily.

 

can you point me to the one with idemitsu oil..if it is pao and ester based it should do better than regular syn oil.

can you also tell me what kind of maintenance(oil change) paper work did dealer request of you for your engine changes. so I can be ready if that day arrives :-)

 

No one that I know of has ever done a UOA on idemitsu in an 8. keep in mind though that I am pretty sure Honda 0W oil is idemitsu. So.......................