OK OK I know this time I have gone way to far overboard.

Really I do not think you are a twatwaffle. I do think you are way to passionate about a topic that you have done no direct testing on; all you have is your personal experience with your own car.

I am a mechanical engineer that has helped design and built and some of the fastest engines that move over the face of the earth and even in the air.....

My views ----> Run a high quality synthetic oil from a reputable manufacturer in a grade that is some what close to what the manufacturer recommends and you will be more then fine.

Really these topics are even debated by some of the best engineers I know let alone forum dweebs..... Seriously you take a 20w/50 oil and a 0w/40 oil and get them up to temperature and the differences in viscosity is so negligible that neither of the two will stop metal on metal contact unless one oil is of way better quality.

Summary

Good quality oil from a good manufacturer and when in doubt change it more frequently.

 

Looks like if there is not enough pressure the system stays in the high state.

http://forums.rennlist.com/rennforum...-a-primer.html

 

Ha ha ha. Love guys with a sense of humour.

You know what, I did say I won't come back and have you the last word but honestly with this post of yours I agree 100% and I am sorry we had such "juvenile" exchange. But it was kind of fun. I am sure many forumers enjoyed it :-).

I also agree I've got a tad over passionate but I do hold a MSc degree in engineering and I do get a tad pissed off when web theories and cleverness go on a rampage "by some".

I would just kindly correct you if I may, I don't just have experience with my own car. In addition to my engineering background I race motorbikes and Porsches and have been around racing all my life. I've lapped the ring at just over 8 minutes and my tuner is a guy who makes turbos for RUF in Germany. It was him who to my shock first without asking me went from OEM Mobile to Castrol 10/60 edge when servicing my car. At first, I flipped and then had a long conversation with him about it. The rest is history.

I kind of enjoyed our verbal exchange but let's not do it again shall we? :-).

PS. if you have a Slavic girlfriend you must be a damn cool dude. ;-).

 

Good find.

 

I love internet oil debates. Let me sum it up:

One guy argues for oil type 1. Another guy argues for oil type 2. Both have multiple degrees and disagree with the other. Both go away and run the oil of their choice....

Wait for it...




Nothing happens either way. (well except that you're branded a nerd-rager on teh interwebs)

 

Ha ha ha! Well put. And I agree. Every now and again it's just hip to be a nerd-rager. I promise I won't do it again - for a while. :-))).

 

im changing my oil tomorrow!! lol

congrats on your new found power

 

Wow.. Really??
All I am going to say here is that I some what disagree your comparison of 20W50 verses 0W40 ,,both being high quality,,because of my findings and contacts with Oil Engineers that have sponsored me in the past with my competition motorcycle engines I have built...
We all have our opinion by the info we collect..

 

Dude are you seriously comparing and AIR COOLED Harley motor to anything high performance; heck even a water cooled HD motor. A Harley motor is a lower technology motor then a modern Briggs and Stratton lawn mower engine. And I really do not mean that to be an insult to you, it is just the truith...

But yes HD motors have a really different set of tolerances and characteristics they operate under. Heat and poor cooling is a much bigger issue with them.

Do you think for one moment companies like Ferrari, Porsche, Lamborghini, heck even Chev and Toyota and ____ are some how using a lesser quality product with an oil of lower Vis then they could if the chose a higher vis oil; and it is all to meet some other agenda... An agenda that was mentioned in this thread was emissions....

The engines you are talking about that you won king of the dyno; or for what ever competition, utilize technology that hails from the 1940's. Thus they operate in a whole different world then a temperature regulated water cooled engine. Shoot even the 9 cylinder Russian radial that is in my airplane is more technology advanced then any HD motor I have ever laid my hands on. I dump a straight 50 wt into my plane.

Modern engine builders are using lower vis oils because the chemicals they are using as additives now are better able to protect engines from wear at normal operating temperatures.. Thinner more stable oils have allowed engine builders to tightened tolerances up between moving components; that gives the engine increased strength and longevity and decreased size.... Hence a 2.4 liter Subaru motor puts out as much HP or more then an old 460 ci ford big block. And in the last few years oil chemistry has allowed for quality oils with bigger Vis spreads (10w60) not to many years ago those numbers would have made for a less stable oil that would break down way quicker. Not no more.

Where the oil chemistry has suffered is at the hands of the environmentalists who have mandated no more or less chemicals like Zinc and Phosphorus in our oils or Lead in gas....

But you are right about what oil should go into a HD. It has to be of good spec to prevent damage from big temperature fluctuations, it has to be thicker to accommodate much larger tolerances and it is a primary cooling component.

Many High performance motorcycle oils are better oils then car oils due to the fact they still have chemicals in them that protect against the final method of engine failure, which is metal on metal contact. That being said those chemicals are a killers of modern emission components like cats and O2 sensors.

Sigh so many trade offs and just no one right answer.

 

DUDE I am talking about 101 motor oil in general no matter what engine it goes in..I am NOT comparing a Harley motor to a Porsche motor any where here..
I have talked to engineers at the oil companies for my education.. I have not just built and raced Harleys but many other types of vehicles that use oil.....
Yes, Oil has came a long way but the basics of it has changed ,some for the better ,some for the worse , like for emissions reasons..
I did not want to go down an argumentative road with you ,that's why I gave you a simple comment in regards to my opinion..
MY take,, You believe that those oils can both have the same levels of protection as you stated in your comparison comment on them?....So, does that mean Endurance Racers, High HP, Hot Climate big buck competition engines don't need oils such as 20W50,,even though oil companies still recommend it?
20W50 is not an emissions oil like 0W40 is..
A 0W40 will break down a lot faster then a 20W50 oil , loose its protection faster and in most cases have a lot less additives then 20W50 ..But the question is do you need it?? To each his own..
Some members on here run 15W50 in there high HP Porsches as some builders/tuners of high HP motors recommend it also..
Its all good and we share what we believe and know and hopefully learn more from each other..

 

I run 0w40w mobil 1 with 2 bottles of BG MOA zinc additive. My car has > 700 rwhp & it lives in a hot climate.

Hopefully this mixture helps.

According to BG:

 

i think 0/40 m1 is too thin for climates with sustained 100+ temps. i never hear the horrible sound of a momentarily UNlubed engine at startup using 5/40. but i do on occasion using 0/40. so i switch to the heavier 5/40 usually for summer months and when i got the kit from ecs in prep for the summer change , i neglected to ask for 5/40 and of course got the 0/40.. and the noise when all the "0" part of the oil has thinned so as to provide as little protection as '0" weight can provide at 100+ temps.. the metal on metal noise ( it's literally a "screech" ) is enough to make anyone switch to 5/40 for summer. doesn't do it with just the switch from 0 to 5 on the lower end of the viscosity.

how scientific is that.

 

Not at all...I would be very surprised if there was much, if any difference between 0/40 and 5/40 at temperature. I would doubt even further there was a measurement system with enough precision to tell the difference.

 

See now I have to say sorry as I used you for a test to see what you would come up with.

John there is no right answer to this question of what vis to use other then knowing what kind of clearances (design factors)you are dealing with inside the motor and what environmental factors. Thinking you need higher vis just because it is hopped up or for some other reason like you want more protection is a bad mind set to get into.

My example is two Toyota vehicles. A Rav4 and a Tundra pick up; engines both designed and built by the same company. The Rav4 needs a lower overall vis on both ends of the multi vis spectrum then the Pick up for reasons of tolerances or clearances that were designed into the engine. Running higher vis oils in the Rav4 could actually hurt the engines.... But all to many people get into the mind set of... I live in a warm climate so I really could benefit from a higher vis oil...

No there is no one right answer to this question, I just ended up using you to create this follow up.

And yes a 40wt and 50 weight oil are fairly different vis at lower operating temps, The facts of that is a standard test temp for oil vis is 100 deg C... The vis's are approximately around 40wt=12.5cSt 50wt=16.3cSt 60wt=21.9cSt, all at 100 deg C..... In my opinion at lower operating temps those are some pretty good spreads; at the higher temp ranges of use (200 deg C +)these numbers become a lot closer to being equal so one oil really does not offer that much greater advantage over one another in terms of Vis.... But at lower operating temps one oil over the other could mean the difference between poor protection due to the wrong vis alone....

The moral of the story is pick the oil your motor needs due to its design factors not just some "wrong" theory that a thicker oil better... Because even in a hot climate it could be the wrong oil in your engine.

So like I said in another post... Unless you have a custom motor and know the tolerances it has and where --> Choose a high quality synthetic oil from a quality maker that is close to Vis that the manufacturer of your engine recommends. And if you do change the Vis vary your driving style accordingly as oil is the very last thing inside your engine to come up to stable operating temperatures.

There are various methods and very reliable and repeatable methods to measure these factors at all temps.

Seriously!!!! Very well educated people write whole books or research papers on oil chemistry and never cover all the variables and factors; they even use very stringent testing procedures and they still come up with the fact that there is no one right answer.

 

i agree, it doesn't make sense on paper. but i've never heard the "screech" that sometimes occurs at hi temp startups, that i have when the 0-40 is in. has ANYone ever heard this momentary lack of oil on startup? or is it only my car? it's only when the engine temp is high. not from a cold start. very strange and only last a second, then oil pumps and all is ( presumably ) coated again.