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so what your saying is the feeling under your foot is irrelevant? And any difference you FEEL is imaginery

dont you feel your engine rolls, dont you just start it and feeel it vibrate and listen to it purr and take it all in so much that when the slightest little thing is out of place you know it... go on rolls, go out and be at one with your machine absorb its presence and sense its being..

Then change the oil...lol

Oh, what about the half that dont fall down?

What i was trying to say was he noticed a difference in idle and it was easier to start, I was just trying to find out which one she thought was the better one cause he didnt say, all he sad was he tried 2 oils and they behaved differently but didnt state which was which

What I was trying to say is he probably doesn't actually know which oil was better because there is so little in it and without proper testing equipment there is no way in hell you would know by just sound.

Car manufacturers don't just try a bunch of oils and decide based on feel what they will recommend, they do lots of very expensive extended testing.

Edited by Rolls

yes i know and they nearly always recomend something between 0 and 40, i mean what manufacturer recomends a 60 oil there is just no need for a street car..

Now maybe this edge stuff has gained a reputation from a crowd that thinks burnouts are the eppitimy of performance, but I dont see any car manufacturers recomending it for dailys..

i know what your really saying is I have no solid facts to base my theories on and you are right. But I do notice or FEEL differences in oils and these feelings I believe can be just as important as any factual evidence.

When you get your car tuned do you just trust what the dyno says to determine the cars performance or do you go and drive it and judge performance by the way it feels to drive.

id say its a combination of both

Or , when the golden gate bridge fell down, do you think a bunch of engineers sat around trying to decide if it was going to fall down, while some guy stood on the bridge and said "holy f**k this thing feels like its going to fall down" he didnt need a group of engineers to tell him that he could feel it!

i know what your really saying is I have no solid facts to base my theories on and you are right. But I do notice or FEEL differences in oils and these feelings I believe can be just as important as any factual evidence.

Anecdotal evidence is it just as important as factual evidence? Well if thats what you think then sure, I don't think you'll find many people that agree with you though.

When you get your car tuned do you just trust what the dyno says to determine the cars performance or do you go and drive it and judge performance by the way it feels to drive.

Neither, if I was trying to compare a difference I would do it on the dyno before, then compare it on the dyno after.

Or , when the golden gate bridge fell down, do you think a bunch of engineers sat around trying to decide if it was going to fall down, while some guy stood on the bridge and said "holy f**k this thing feels like its going to fall down" he didnt need a group of engineers to tell him that he could feel it!

That is like an engine getting a big end knock from using a certain oil (lets say water lol), that is something that you certainly can hear the difference, a minute difference between two engines that are both running fine is not going to be something you can tell by ear though.

I'm going to agree to an extent with Arthur here. The shithouse oil I'm using (Nulon 10w40 full synth) makes it feel as though something just isn't right, compared to Motul 8100 5w40...

Not to mention since using it I have a noisy lifter down near no.6 cyl.

I can tell you like Arthur is trying to - it's bloody hard to explain how you "feel" it. It's not entirely about feeling in a physical sense of the word, but more a "gut feeling". Little things, like the way the car free revs, sounds when it free revs, lifter noise, turbo spool....just these little things that you subliminally notice that cause you to feel as though something isn't as it was before or as it should be.

exactly, its almost instinctive. But even if the oil is doing a perfectly good job it can noticably different. When i went from 5.30 to 10.40 in the honda even the wife felt the difference, there is nothing wrong its a perfectly good oil it just feels a little sluggish.j

Now this may appear to some to have no real world affect to the performance of a vehicle . Then againI was talking to a guy at track day a while back who said he had gained close to 30hp from an oil change, now thats a difference I'd imagine you would FEEL

What you are both describing above is exactly the kind of subjective anecdotal evidence that doesn't show up in the lab.

I admit however that there is not an objective test of all impacts an oil has in the engine and sometimes our 5 senses can be quite acute.

My thoughts:

Anyway, I have done some viscosity testing on new and used oils from my engine (RB25DET) after 7500km. I used 2 oils. Shel Helix Ultra 5-40 and Fuchs 5-40 supersyn or something. The viscosity was only slightly less at both 40° and 100° for the used oil so I gathered that my engine must be in decent condition as there was not much thinning of the oil due to fuel. The results was like 3cst less at 40°, which is 1% fuel dilution at most. Obviously viscosity does change dynamically in the engine under shear forces (due to polymer additives) so lab measurements can only mean so much.

Getting the right viscosity, I think 5-40 or 10-40 is a good street viscosity, up to perhaps a 50 weight with synthetic base is the major requirement. A 60 weight oil is really only good for racing, especially endurance racing, or a rebuilt engine designed for it (yes, I know Nismo recommends 60 weight oil)...for racing! Using a 60 weight oil in the city when starting temps are <20°C is increasing bearing wear a hell of a lot.

Lighter weight oils and modern cars. A lot of manufactures are now stating 30 weight oil, or even 20 weight. This is mostly so the cars use slightly (~2%) less fuel and generate less Co2 (for tax in Europe) and pass the oil efficiency standards. Especially in the empirical lab testing this lighter weight oil yields better efficiency but is almost certain to cause higher wear which is only evident once out of the warranty period. Going down each viscosity grade will decrease fuel consumption at light loads around 2 to 3%. So going from 50 down to 30 would be a 6% improvement at best if driven very carefully. If driven hard there would be less benefit.

Edited by simpletool
I can tell you like Arthur is trying to - it's bloody hard to explain how you "feel" it. It's not entirely about feeling in a physical sense of the word, but more a "gut feeling". Little things, like the way the car free revs, sounds when it free revs, lifter noise, turbo spool....just these little things that you subliminally notice that cause you to feel as though something isn't as it was before or as it should be.

I bet if someone changed the oil for you and didn't tell you what oil they used you would not consistently get these feelings, if you don't believe me get someone to do it, get your normal oil and a 25-50w and get them to not tell you which oil is in the car.

Drive it up and down the street a few times and I guarantee you won't be able to guess, if they've put the shit oil in then change it afterwards.

awesome , so im not going crazy :thumbsup:

what I would really like to know is

would you recomend the fuchs supersyn cause I can get a great price on it.

Was goin to get 5_30 as per standard but longevity is a bigger concern to me than anything else so maybe the 5_40 would be better and I could buy in bulk and run it in all 3 cars

cheers

I bet if someone changed the oil for you and didn't tell you what oil they used you would not consistently get these feelings, if you don't believe me get someone to do it, get your normal oil and a 25-50w and get them to not tell you which oil is in the car.

Drive it up and down the street a few times and I guarantee you won't be able to guess, if they've put the shit oil in then change it afterwards.

I've never said the change was immediate, though even if they used the good oil I would still pick up on minor changes.

Like simpletool said, our 5 senses are amazing. I pick up on things wrong with my car that while may not be anything major at all, are certainly there. Even things like what I'm feeling through my right foot on the throttle compared to my left foot on the rest might raise an eyebrow for me. Not entirely blaming it on the oil, maybe even I'm a little pedantic and pay more attention to my senses after an oil change hence why I might notice these things more.

Though for something like lifter noise, I can guarantee you that has arisen since my last oil change. No ifs or buts about it, this oil has conveniently lined up with my lifters making noise be it the cause or not.

Fuchs Supersyn in 5w-40...yes. Good stuff and usually well priced.

I'm sick of the local shops being pathetic and only having Pentrite oils. That's right Repco and AutoPro I'm talking to both of you!

Edited by simpletool

You might be an engineer Rolls, but a mechanic doesn't diagnose mechanical issues in a car using X-rays and sending off individual parts for analysis of structural integrity. They look for cracks, they listen for knocks, they smell for burnt and they feel for broken. The first order of business is always a test drive of the vehicle or get it up on the hoist to have a listen! Nothing wrong with using the senses to gauge all this. And given oil is the life blood of an engine, it makes sense that something flowing through the biggest moving part in the car will make a difference to how it feels.

The bottom line of it all...these are sports cars that we drive to enjoy them. So factual objective evidence aside, I don't care if an oil isn't as good as another, if it makes my car feel better to drive, I'm going to take that over the better performing one. On the subjective note though, it's not always a placebo effect. Placebo usually entails a falsified positive experience, but people here have also noticed bad things after an oil change...e.g. with the Nulon stuff.

You might be an engineer Rolls, but a mechanic doesn't diagnose mechanical issues in a car using X-rays and sending off individual parts for analysis of structural integrity. They look for cracks, they listen for knocks, they smell for burnt and they feel for broken. The first order of business is always a test drive of the vehicle or get it up on the hoist to have a listen! Nothing wrong with using the senses to gauge all this. And given oil is the life blood of an engine, it makes sense that something flowing through the biggest moving part in the car will make a difference to how it feels.

The bottom line of it all...these are sports cars that we drive to enjoy them. So factual objective evidence aside, I don't care if an oil isn't as good as another, if it makes my car feel better to drive, I'm going to take that over the better performing one. On the subjective note though, it's not always a placebo effect. Placebo usually entails a falsified positive experience, but people here have also noticed bad things after an oil change...e.g. with the Nulon stuff.

My mechanic tends to diagnose faults in my car by A: drinking alot of piss & then B: telling me to go buy something better.

Also Placebo is a really shit band.

What everyone is actually talking about is confirmation bias. You expect your million dollar oil to make then engine feel better & lo and behold your head confirms it.

but im not talking about million dollar oils at oil, ok I have motul in my skyline, 70$ for 5l its hardly cheap but there are more expensive, it seems to me to be a fairly well proven oil for turbo imports so I think its worth it, i ws using mobil one before which was just as expensive anyway and Im thinking of changing to fuchs cause its half the price but if I put it in and it doesnt feel right I will change back..

But my main experience comes from 400,000kms in my old ute. I tried lots of different oils had had mixed luck in the end my favourite was RSOL from reco, 20 bucks for 6l with a free filter it was damn good value. Shell helix I used a few times and it was really good. Engine felt smoother than the RSOL for sure but it was only justifiable when on sale. Castrol magnatec was rubbish, it felt ordinary and burnt out within weeks I was amazed when I checked the oil and there was none there. Most other stuff like mobil and penrite was always good. I didnt bother putting expensive oils in it.

At the end of the day i want a mixture of quality, value and it has to feel right when I drive it..

Saying how it feels is irrelevant is like buying a car from without test driving it Because the brochure looks good

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