DOHCTR

Hi Everyone, As I was searching through google, i cannot believe i was reading this post. In the least harsh and blunt way possible i will try and explain in detail all the things incorrect about your statement. I am not "having a go at you" i am simply trying to educate you and prevent other people from misinformation. Don't get me wrong i can understand why you thought the way you did. For a start.....oil viscosities......If a ROYAL PURPLE oil is rated at 5w30 and a MOTUL oil is rated at 5w30 guess what? at the API and standards testing temperatures they are the same viscoscity, one is NOT thinner than the other..... NOW, for the statement about Royal Purple being "thinner" causing "more engine wear" couldn't be more incorrect.... matter of fact it is the COMPLETE opposite. A thinner oil will decrease wear and decrease friction (within boundaries of manufacturers specifications)... here is a better suited analogy...If you were to run hard cheap tires they have little traction however they last longer (LESS FRICTION), if you used soft compound racing tires you have more traction but they wear quicker (MORE TRACTION). Now in order to create more power in a combustion engine you need to increase volumetric efficiency (fuel/air mixture compared to total volumetric capacity) or decrease opposing forces, a thicker oil will not pass through clearances well and cause greater friction causing greater wear (similar situation as soft compound tires), however the thinner the oil the greater the lubrication and less friction, they claim more power as the engine is being lubricated BETTER creating less internal friction (which is an "OPPOSING FORCE"). A thicker oil should ONLY be used in a situation were your engine has been rebuilt to something other than manufactures specifications or your engine is suffering from extreme wear (even then ask your mechanic). HOWEVER, there is a downside to an oil that creates a thinner film, although it lubricates better the film strength is weaker, so under prolonged extreme temperatures it is prone to dispersion of the film promoting engine wear (This is why usually the use of thinner oils employ synthetic esters and oils, that are developed to combat these issues compared to thinner petroleum based oils), however even race cars use a similar film strength, for spirited driving or even occasional track, there is absolutely nothing wrong with royal purple oils. Testing has proved them to be very good. In conclusion, if you're running a streetcar and running the manufactures standards, you would be lucky to prove a difference between most half-decent oils. A base mineral oil that the local dealer supplies would be more than sufficient. Only in these extreme conditions are these oils needed, or the age-old issue of "having peace of mind" knowing you're using "the best" or something that by far exceeds those standards of what your manufacturer recommends. About your camshafts, thats bad luck. However I highly doubt it was due to the brand or base of the oil you were using. An oil of the same viscocity regardless of brand (something half decent, Motul, Fuchs, Mobil1 etc) will not cause this much wear. Wether it was Nissan Basic Mineral oil, or the very best Motul 300V (if they were the same viscocity, unless it was under very high amounts of stress or in unusual temperatures, you would be lucky to prove a differance). If it were true it would be due to the viscocity used. Also if it were to be the oil, it would of affected other parts of the engine alot worse before it affected the camshafts. Also an interesting fact considering everyone here is a Nissan fan (so am i even though i have a Honda) the Volumetric Efficiency i am talking about is in relation to fuel/air mixture compared to total volumetric capacity. A Forced induction engine is technically the only way to push Volumetric efficiency over 100%, all in all a naturally aspirated engine will only be able to run at best 100% volumetric efficiency which is almost impossible without air induction intakes like on the sides of Ferrari's. Thus, where the saying "There is no replacement for displacement" originates. Sorry about the spelling and grammar, not the best, but I was in a rush and ended up writing a lot more than expected. Hope this helps. Regards, Andrew.