Trex101

No, RP is mostly group IV couple with mineral additives carrier fluid (possibly group I for total additives solubility). Alot of ppl in BITOG has criticize RP for it's lack of shear stability but UOA results always prove very well under high load and stress situation. It's good oil but not 100x better than the rest i tell you.

Oh yah, that will be interesting.

Ok, not race but hard condition, this is 2 example where i did a quick search. There's more UOA in BITOG i'm sure though. S2000 My Webpage Accord 2.4 My Webpage

UOA is pretty avg for normal day to day use but it is under race and track condition that RL excelled.

The fact is all engine oil be it synthetic or mineral (other then ester base fluid) will drain down to the sump after a period of time. That's why Motul 300V or Redline oil cost so much as they use ester base fluid which is polar in nature and "cling" to the wall without ever draining dry. I would go with Redline if budget permits as they use polyol ester as it's base stock (there's alot of different ester). polyol ester is the only lubricants which can withstand the tremendous heat of modern jet engines. Polyol Ester

Any reason why one of the rim crack?

If it's an unknown maintenance history, i would just change all the fluid. Including engine oil, gearbox oil, diff oil, brake oil, power steering fluid or whatever fluid you can find. IMO, its cheap insurance for your beloved ride. Type of fluid will depends on your budget but i will not go cheap on gearbox & diff as they are normally 40-60k OCI.

For the above available choice, i suggest you go for RP 10w40 and run 10k. The HTHS for RP 10w40 is pretty strong at 4.02

I would say choose a good synthetic and go 10k OCI, it's cheaper and protects better than the "avg synthetic". Cost per mileage will be cheaper. Everyone know that Amsoil website is pure propaganda and can't be taken too seriously. Take it with a pinch of salt.

Generally not true, it's the condition of your engine that determine the viscosity needed, not numbers of years. In fact if you have taken care of your engine using quality synthetic, you shouldn't be seeing much engine wear. FYI, I'm using 5w20 oil for my 130k puny honda engine and it doesn't consume a single drop of oil. The engine pull even stronger than when i first get it at 16k mileage.

Both M1 0w40 & Castrol 0w40 are group IV PAO base but M1 reputation is better with track/race proven and the oil is $20 cheaper. It's a no brainer... Go with M1 0w40.

Got no idea about the engine oil but the engine oil additives looks dodgy. How can PTFE is used in the engine oil? Sound like a "Slick 50" type of advertising to me. More information on PTFE in engine oil. PTFE

I would say, go for the Mobil 1 0w40. Best deal then the rest propose above.

Redline 75w90 GL-5 That's for the diff only while the gearbox can use Redline either MT-90 (75w90 GL-4) or Lightweight Shockproof (75w140). I go for the later if under heavy load or increase boost.

Any 75w90 GL-5 fluid will do.

No, he is previously using Denso IK16 with no problem which is on the same heat range as the NGK 5 series. Most likely it's the gapping problem.

The bigger the "number" for NGK, mean the more heat it will cool the combustion chamber. Try gapping your plug down to 0.8mm. The gapping tool will look something like this.

Now i know what wrong, you are using the wrong gap. Try gapping your NGK to what your iridium is running and you will be fine.

You should get BKR6EGP instead and gap to spec, btw the difference between number 5 plug and 6 plug are 70-100'c. You could be running too hot in your turbo engine. What gap are you running on your iridium?

PP got pretty good review over in BITOG, it make up of mostly group V (not ester but EOP) base stocks. If it's cheap just use it.

You can actually rate Redline lightweight shockproof as 75w140 but it is build very differently. One of the must have if you are generating big power. Clink link below for more technical details: RL lightweight shockproof

The flash point for RP 10w40 are only 204'c (HTHS 4.02), the RP 15w40 flash point do look better with 224'c but (HTHS 3.6) only. IMO both not really ideal for hot running turbo engine. The RP 10w30 do look better with flash point at 235'c and HTHS of 3.3, i would say go for the 10w30 for faster turbo spool and better thermal stability.

Oh, these are Nissan japanese part number. I got those from my Nippon catalog.

The actual Nissan part number for R32, R33 (RB25DET, RB26DETT) should be AY100-NS007 (15208-H8911) but has been supersede by AY100-NS005 which is used by R34 so both can be used.

Redline Water wetter is not recommended for winter used, only suitable for summer or track use. If you must use RL WW, pls mix at least 15% coolant and the rest distilled water. Power steering fluid or ATF in radiator is a major no no. The viscosity of the fluid usually 7cSt or more will decrease the heat transfer rate of the medium (fluid) by hell of alot. General guide PSF or ATF ~ -50 to -70% decrease heat transfer 50/50 coolant/water ~ normal heat transfer RL WW/100% water ~ 50% better heat transfer