i just need an answer because i went out and brought 5.5 litres of castrol gtx oil 15/40 is this the right oil
Any quality 15/40 oil of a suitable rating will be fine, do not buy into the "must be synthetic" bs. GTX is pefectly ok.
I use full synthetic Nulon 15/40 in mine always been fine. The full synthetic thing is just what ive read here time and time again.
Nothing wrong with synthetic, but just because it is not a synthetic oil does not mean it is inferior.
Too thin. Cold tolerances on the VG aren't tight enough for 0 weight. Mine was rebuilt about 20,000 ago, with all the forged goodies and new bearings, etc. After run in, I've used Penrite SIN 15 ever since, changed after every track day, so basically ever 1000km at this stage. If you run it too thin you have cold oil pressure problems, and cold lubrications problems.
Given that engine "tolerances" are by and large engineering standards and little to do with individual engines, sorry M8 but that comment is more or less bollocks. 0-40 is a 0 weight oil that behaves same as a 40 weight oil when hot at 100 degrees C. THAT is how it works with multigrades due to the funky additives that have vastly improved over the years resulting in some pretty wild (apparently) viscosity extremes! years ago a 30-40 was pretty speccie! No magical changing of oil weights at some predetermined temp or time...! Its very simple. Id much prefer light sewing machine oil running around my engine when dead cold than treacle. In my view, 0-40 perfect if you feel like paying for the priveledge. Necessary tho..........? Nup. Not in a million years! L8r E
well I got it free off a castrol rep and was a little worried it was too thin, but as you said it all seems a little bit of marketing here and there to woo the buyers. that said, is it worth the risk? or honestly, not that much of a difference? between say a 0/40w and a 15/40w ?
Dunno the manual states you shouldn't be running it that low unless you are in freezing temps http://www.300zx-twinturbo.com/cgi-...=0&cycle=off&slide=11&design=default&total=33 I'd probably be following the manual more than anyone else on here, I've also been told 0-40 is too thin also read it somewhere, long time ago but oils that have huge Viscosity ranges are inferior also, I dunno how true that is or care just follow the manual and you cant go wrong in my opinion. Some other guys might be more knowledgeable like a2zed said, a lot of Synthetic oils are inferior to semi Synthetic....and you pay out the ass for them for the privilege lol
TBH I've been told by a Penrite rep that 0W-40 is not too good in our climate, especially for a car as old as the zed. As a guideline I use Castrol Edge 10W-60. Planning to use Penrite Sin10 10W-70 during summer. Adam
Fark dunno if I'd go that high, wouldn't go any higher than a 50 grade and that's for our summer lol I use either 10 or 15-40 for anything but summer and a 10 or 15 - 50 for summer, works perfect
I'd be a bit weary about oil "reps" as it's quite likely they don't know dick about cars... It's akin to asking a petrol station attended about race fuel types. When in doubt refer to the factory service manual!
Finally the reference to the manual - I think your on track so far. Thats just about right - japan is colder on average so in the manual it is 5-10 degrees on average hotter in oz. You need to first calculate the highest temperature and lowest temperature of your local area as Australia has many climates W is for winter rating - not weight? Engineers generally say that the thinner oils below 5w run through the turbos easier and cause excessive carbon deposits and greater wear, however if its constantly below minus (you live in Canberra) You may have no choice. After the invention of multigrade oils, Oil Engineers say that the best oil is the grade with the minimal difference at any season, so that the molecules are as even in size as possible but they must be able to penetrate the bearings even in the cold. I run 10W - 30 in winter and 10W - 40 in summer, but that's because my temperature averages that. The manual averages 10W - 30 by default but it is also based on japan (canberra weather - subtract 10 degrees C on average) and I also have sticker from nissan in my car that indicated not to use an oil less than 5W - thats from the factory! The manual however does list lower oils (you might live with penguins and have no choice) You will know the best oil in the end by trying different mixtures (you shouldnt mix oils) after several changes and watching your oil pressure - finding the oil that produces high flow on idle and lowest flow whilst revving is normally a superior oil provided it can penetrate the bearings when the motor is cold. It means that when its cold its lubricating and when its working hard the oil doesnt suck up Horsepower by pushing a heavy oil around and you get better economy. Nothing wrong with Synthetics, they often have additives like suspenders and detergents whereas non-synthetics may not, but they are more expensive and you still have to change your oil at 5,000 not 25,000 as some people would have you think. AMSOL is the best but bloody hard to get and expensive, GTX is also a good oil. Valvoline is a recycled oil (the molecules are more malleable but it does not produce the high results like AMSOL or GTX. They both have good results in knock/shear tests. Royal Purple is reportedly good but I havent seen the results in the same tests suffice to say it is used in Racing Circles. Regardless you need to work out your temperatures first when selecting oil as people live in different climates
For information I am going to test the Redline Synthetic (at $150 for 3lts ), in the E-Vade. This is more due to emissions, but I will let you know the results as we will have it on the dyno and will be sending an oil sample off for testing along with the previous oil (Penrite sin15). So I will be able to supply a technical analysis of the two, and a comparison between the them, in regards to power (friction), emissions (evaporations and bore washing), and chemical properties (cabon suspension, detergents, TPN, viscoustiy, etc). Just have to fix the E-Vade first, the gear selction cable melted. The cats got a bit hot, so I am changing them out too.
