slidetaker

300V Power should have a closer viscosity range to OEM than Chrono. However, as stated in Motul website, I do not know why Power cannot be mixed with other oil whereas Chrono can.

That is the reason why it is important to go through all 40ish pages of this thread. I am sure that OEM viscosity rating has been mentioned multiple times. Applying the logic, one would think that 15W-40 is fairly outside the OEM spec especially at room temperature. From a 7.5W to 15W. While the some of the recent posts have mentioned 5W30 and a lot of people have been happy with this viscosity. 5W30 also spreads over the 7.5W30 quite perfectly. Read, use common sense and make your own judgement.

I am more interested in who recommended you these oils with these viscosity rating? As I remember RB is using OEM 7.5W30...so I will recommend looking at Castrol Edge Sport or Mobil1 in 5W30 viscosity rating. These have no problem lasting 5000km OCI.

There is sludge and vanish build up in the valvetrain area and then there is sludge like material clogging the oil filter. I believe they are different, just think about the temperature different between these two areas..... Then there should not be a relation between burning (oil consumption) and sludging.. Burning will likely leave carbon deposit in and around components of the chamber... Sludging are more due to high heat and baked-dry up oil.... Don't know may be someone who have more experience can chip in.....

If it is just a drop every week, I would not worry about it. You could try to trace it so you know exactly where it is leaking from. Probably just some bolts and nuts not tight enough.

I am just exaggerating, I am sure you understand what I am trying to say. In terms of oil consumption, that's a perfect example. If you find out that with the conditions of your engine and your driving style, Edge Sport did seem to be burnt off more than X-cess. That X-cess is perfect for you. P.S. personally, I think oil consumption have more to do with viscosity VS oil pressure and add packs than based stock oil.

Technically, for 5W30, Motul X-max(5W30) has a closer viscosity than X-cess(5W40). There are also Mobil1 5W30 silver bottle silver cap that I have seen around. So there are heaps of choices. Not just Castrol.... I see no advantage in using higher quality based stock oil if a person is doing 3 summer months, 5000km OCI driving in grandma style.... So there is no good or bad oil, just depends on your application, OCI, driving style, weather conditions....

yeah....apart from the "far from reality" issue with the test.... is it just me or is the "covered oil" having a different viscosity than the Royal Purple? For all we know, that "covered oil" could be coconut oil.....

I think Redline and Motul are quite specific of which Group base oil they use in their range of oils. You can go to their website and also the hardcopy Motul Brochure in the auto-retailers store have these informations. Most brands will not disclose these base oil information to the exact as it is highly related to the formulation of an oil. But from their MSDS, specs (HTHS, VII) and general descriptions, after viewing a few of these, you can start to tell what largely an oil is made up of. Most brands also give general indication like mineral, conventional, semisyn, syn blend, syn, fully syn.....Oh...not to mention the pricing too...at the end of the day, you get what you pay for.

Which brand make 0W50? The 1st post is saying 40wt has a viscosity around 9cSt at 120C which is the same viscosity of a 20wt......BUT AT 100C..... At 120C, a 20wt will lessen its viscosity less than 9cST, if you have to ask, I am guessing around a 6cSt. A matter of fact is the viscosity gap between SAE oil weight reduces as it is reaching extreme heat. In your case if your engine is constantly in extreme heat, 50wt will give you better protection, beside, a 0W50 is going to be on the light slide of 50wt unlike a 20W50. Fix your cooling system before an oil cooler. If your coolant, radiator, water pump and thermostat are working fine, there is rarely a case which requires an oil cooler.

How hot is hot? Generally, HTHS of a 40wt oil is around 3.7 to 4 cP. That's is more than enough for RB engine on track, especially, if performance oil like 300V promoting 0% shear with good proportion of Grp IV, V base oil. In terms of thinning, a 40wt and a 50wt thin down to a very similar viscosity in extreme heat temperature. However, a 50wt will have a thicker film thickness particularly in mixed boundary lubrication. Don't see 60wt be used with any application in a Skyline. A bit extreme.

I missed, there is actually a question there. On street, Mobil 1 5w30 silver bottle silver cap would be a good choice, not sure whether it will last 10KOCI, should be fine if you clock 10K within 6 months. Motul X-max 5w30 is another one that looks very good in paper. Ester based with quite recent manufacters' approvals. On track, as mentioned, any Redline or 300V 40wt will return good results. The cooling system does not give any specific numerical indication of engine temp. So it does really tell how hot the engine is running. Even the engine itself has some parts that runs hotter than another. Hands up for all the effort of putting up the specs and information from Penrite on their website. It is the most comprehensive I have ever seen. However, their products does not look that impressive comparing to Mobil, Shell, Castrol, especially in HTHS, cts and TBS attributees.

In this case, pretty sure is the Shell then, quite disappointed. Probably some small proportion of Group III not holding up. To have 350ml over 5000km is not good. Have you tried Mobil or Castrol products? Any feedback?

First of all, 90C and 105C is not that hot for racing. Most oil operating temperature are designed at 100C. Oil goes thinner when hotter, so it flows faster to bring away the heat. This is what I understand. You just had a standard rebuilt, OEM oil spec for Skyline called for 7.5W30, it is not a problem to go to a 40 weight on track. Viscosity between the 30 and 40 are closed if the temp goes to above 105C. I am sure you will have no problem with a Redline or 300V 40wt on track just as so many other people had done. As for pressure on idle and through the rpm, other people here should be able to give you some numbers.

Very interesting test. Basically, Shell sludge, Motul no sludge, Shell sludge. Just a couple of question to clarify the test. 1. Have you noticed any sludge or vanish inside the engine before the test? 2. I assumed same type of filter throughout the test? 3. Did Shell consume more oil than Motul? It really is rare that there is any sludgeing with a full syn oil doing 5000km. Logically, I think that what might happen could be that Shell actually was cleaning the engine better than Motul. The sludge that was trapped by the filter, was not resulted from burnt Shell but existing dirt from the engine. Helix Ultra could actually be dissolving the minor deposits built-ups. Nevertheless, it would be good to do the test again now that you have done a few consecutive Motul. Also, Helix Ultra just recently got SM rated. If that means anything to you.