Engine Oils - Whats Good/Whats Bad

[jungle]

Looks this is a massive topic and a lot of explanation is required which I'm not really interested in doing. I will however put up some points to you guys for thrash out.
I'll use 10W-60 as the example.

SAE Society of Automotive Engineers dates back to 1911 and has a lot of assumptions which i won't go into, but safe to say, originally oil ony had a "hot" number which represented the ability of the oil to flow through a test subject at 100C.
As engines developed for colder climates a cold temp was added along with a W that stood for Winter.
So the first represents the ability of the oil to flow when cold ( typically a negative temp)
The 2nd number is the working temp 100C.

Now i'm certainly not an expert & don't know everything, but the lower the first number, the better the cold cranking flow will be and it's ability to flow at really cold temps. The higher the hot number the thicker the oil will be at working temp. So for performances engines or engine under load a lot of the time or that just run hotter, the higher Hot number will give better (more) oil between the moving parts like bearings. It will also provide more resistance and fuel economy will decrease [Im talking like 1% here] but will give better engine longevity.
The lower the hot number the more it will flow at operating temp but you'll have less boundary (oil) between the moving parts.

Please note i'm NOT talking about Viscosity Index VI, that is different again that's really out of my league and not the main topic of discussion here.

Again, i'm no expert but there is certainly room for you to change the manufacturers spec oil based on the temp [climate] your engine operates in.

So back to my 10W-60. It doesn't get very cold here in SE QLD which is why i use the 10W. It does tend to get pretty friggin warm at times and with the Leggy not running an oil cooler ....yet.. i run the 60 to give better hot temp performance. Now it costs me a small amount in fuel consumption, but i'm happy to do that. I also am happy to have more boundary at the hot temp than less. That's me, and the reason i run it in the Leggy as well as the track car and GTR as they both have a lot more power than standard and get "hot" for a long time. Now even with the oil cooler on the track car i still get to 110C which is where i have an alarm set on my logger which tells me to get back off and do a cool down lap. I'll be going to a larger oil cooler as 5 laps is all i get. Most oils start to break down around 118 so that's a measure i use to prevent it. plus i change the oil after every track day as the stuff just gets flogged. Its pretty thin and crappy when it comes out too.:thumbdown:

now if you're in a colder climate ie unzed the 0-30 may be perfectly fine for you.

Hope that helps and gets some discussion going.

 

[bradc]

Good synthetic oils don't break down at such low temps though. They are capable of exceeding 130C without a problem. Emphasis on good though, some might not be so capable

 

[Fully]

Here is a good article to read to expand on Simon's post.

This article is going to look at six of the most important properties of a motor oil readily available to the public: viscosity, viscosity index (VI), flash point, pour point, % sulfated ash, and % zinc.
http://www.howstuffworks.com/framed...ww.repairfaq.org/filipg/AUTO/F_oil_facts.html

Laymans version
http://www.upmpg.com/tech_articles/motoroil_viscosity/

 

[MackTheKnife]

All that said, i'll stick with Castrol Edge 5W-30. I'm sure there's reasons they require a low viscosity oil.

 

[BCX]

I used Nulon 5w-30 100% synthetic a few times, now i've put in Nulon 10w-40 Synthetic as we're coming up for summer (and the constant load-sharing blackouts when in heatwave conditions lol). I've noticed my lifters arent as noisy with the thicker oil.

i've previously bled all 24 lifters in diesel, and they were fine for a week then started to come noisy again with 5w-30. now they only tick for a few seconds with 10w-40.

 

[fieldy107]

I am thinking thinking of changing to 0-40w, its only just higher then 30 and it is pretty hot where I live

 

[bradc]

Shane, I know what it all means, I'm not asking that. I'm talking about why at 100C oil temp Mitsi suggest a 30 weight oil, and that unless you are on the track your oil temps aren't going to go above 115C as the whole point of the water cooling is to keep the oil around the 100C mark, regardless of the ambient.

 

[Rosco]

im only going to use extra virgin in mine, i use it in pans all the time, and theyre way hotter than my engine, not only does it take the temperature but it smells great too!

I wonder if i can get fully synthetic extra virgin?

 

[jungle]

ha ha. I knew this would stir sh*t up. Its not an easy or simple topic, many variables and even the experts don't necessarily agree on it.
Great link Shane!
I've explained what i use and why i use it. Hope its food for thought.

 

[SiliconAngel]

I love the kind of religious nonsense spewed out over this topic (and many others, come to think of it). I completely agree with you Simon - so-called 'experts' frequently disagree over lubricants, which is really insane as we're talking about something scientifically measurable here. It's really not that hard. If at a given temperature range a lubricant is capable of providing a lubricating buffer between engine components, then it is up to the job of lubrication. If it can perform like this without breaking down over an extended period of time (say, 5 or 10,000kms worth) then it is worthy of being in your engine (at that temp range). If it breaks down over a shorter period, then it should only be used in drag cars (Royal Purple is a perfect example - excellent lubricating properties but poor stability, so it can't lubricate effectively after a surprisingly short duration. Perfect for drag cars and not much else).

You're also correct, Simon, that a track car is going to run at a much higher temp than a standard road car and attention should be paid to the cooling system and oil temperature range. However, Brad is also correct in that Synthetics are designed for reliable stability at a higher temp range than you should be capable of experiencing on an ongoing basis, even in a track car. And not all oils are made the same, so it behoves you to ensure you are running the correct oil for your vehicle and application. Simon is erring on the side of caution, ensuring he is running an oil that will withstand the punishment he gives it. Brad recommends a lighter, high-quality synthetic. Both are valid arguments. I have provided at least two comparison studies in the past showing performance of numerous brand-name oils in scientifically conducted wear analysis, so the interested reader is directed to find those.

At the end of the day, the reliability and longevity of your engine will be determined by your choice of oil and the frequency of servicing (as even low-quality oil won't do that much damage if changed frequently enough). It's really up to you which direction you choose to take, as no one else will be driving your car or actually putting oil in it.

 

[ttgvr4]

Simon my mechanic SKR is on the exact same level and told me to run nothing less then 15-50, and he worked for mitsubishi for 30yrs, when i gave him a bottle of 5-30 he wouldnt put it into my car, plus he has seen first hand what thin grade oil does to internals and living in Adelaide summers can be very hot and dry, no lifter noise at all

 

[SiliconAngel]

he has seen first hand what thin grade oil does to internals

Me too, although I realise your insinuation is that 'thin grade oil' leads to damage, whereas I have seen examples of the opposite. The thing about your argument is it's all encompassing, simplistic and not at all scientific. I won't go so far as to say it's baseless, because you have based it on the opinion of someone you obviously trust, and that's fine. But you're suggesting that oils should be primarily evaluated and categorised by their viscosity, regardless of the manufacturer or type of oil (such as mineral, blend or synthetic), which is a little naive. Two different lubricants from the same manufacturer can have utterly different lubricating properties, let alone from different manufacturers. I can pretty much guarantee 'SKR' has never seen the inside of an engine that's been running on Amsoil (of any viscosity). Conversely, how many 6A13TT engines has he pulled down that have been running 0W30 or 5W30 fully synth (for their entire life)? It's entirely possible the examples you're referencing were engines designed to run a higher viscosity lubricant, but the owner put a thinner oil into it under the misguided notion that thinner oil = racing oil = faster car. Running thinner oil than an engine is designed for will lead to problems, but so will running a higher one. As I said here, running thicker oil means the oil will be unable to lubricate all engine components adequately because it is physically too thick to reach some of them (due to extremely low tolerances in component design).

living in Adelaide summers can be very hot and dry

Again, the argument about increases in ambient temperatures is irrelevant because the cooling system in the engine is designed to keep the engine operating within a 5°C temperature window. So whether it's -15°C or 45°C outside, the engine operating temp remains the same, thus the oil viscosity should remain constant. As I've stated previously, sticking the car in track conditions WILL alter this calculation, but such concerns are way beyond the scope of a street car discussion (and besides, before you go selecting your race-condition lubricant, you need to do a complete redesign and overhaul of the stock cooling system anyway).

no lifter noise at all

That's because your oil is thicker, so it doesn't run past the worn lifter diaphragm as a thinner oil will. So you're just masking the problem of your failing lifters - it's not a measure of anything indicative of a healthy engine environment.

 

[Jimmy_EC5W]

Very good argument. Highly agree.

 

[frank_t]

Did my oil change a few weeks ago and thought I'd share my results (previously running Motul X-Lite 0w30 and getting a bit of lifter noise on start up).

So after dumping the old stuff I replaced it with a cheap Mobil oil and new filter as a 'flushing' oil. After idling the car for about 15 minutes I dumped that oil and again replaced the oil filter. Then I filled her up with Motul's 300V Power Racing 5w30 oil and added Nulon's E20 additive (just another PTFE based product). And I must say this has done wonders to my engine. So quiet and smooth, no lifter noise ever and the oil is very clean when I check the level. Only downside is the ludicrous price of the Motul and it was kinda hard to find on shelf ($30/L).

Hopefully this helps someone cure their cursed lifters

 

[mchieff]

Holy crap - new lifters are about the same price as one change of that oil!
By the time you put your flush oil, filter and additive on the price i think you'd have postage covered as well!

 

[frank_t]

Haha, but sadly true. However i really wasn't in the mood to change them. Probably just need to find a better source for the stuff

 

[Guest]

I had lifter tick develop in my VR-4 to a point where it was constantly there even when warm... even after flushing and replacing with brand new oil, start her up again and tick, tick, tick. Yes, the tick was there immediately after a service and wouldn't go away. For the last few changes it has just stayed this way. But when I originally bought the car it was lovely & quiet.

After carefully trying many different filters and oil weights and brands, including Group 4 PAOs and finally an expensive Group 4 Ester, I decided to try what worked for my old car - and that was to switch to a 'cheaper' oil. I change the oil every 5000kms so really there is no need for me to go overboard buying the finest oil available to humanity. You can read about the different oil groups here. And I would never, ever put any of that horrid teflon or moly additive into any engine I cared about.

Last service, I switched to a lower quality oil, a Group 3 full synthetic - Shell Helix Ultra 5w 40. Group 3 oils, even though saying full synthetic, are still derived from mineral oil. Well, the ticking immediately went away, and has now stayed away for a few weeks. I expect it will stay this way until the next service time nears. It will be interesting to see.

The filter I'm using is a genuine Mitsubishi MD356000, I don't think it plays any part but it's the first time I've used this specific one so will need to find out for sure. I used the other one in that thread last service, but still had ticking.

For the record my other car is a Hyundai Coupe that uses the same type of lifters (HLAs). It was running Mobil 1 full synthetic up to 100,000kms and the lifter tick set in bad. I switched to Penrite HPR 15 semi-synth (yes, a bit heavier) and the ticking disappeared and has stayed away - and that car has now travelled 240,000kms on the original lifters and I have no need to change them. The engine has been the only part of that car that hasn't given me any trouble.

 

[Slinz]

^ That is interesting and I have had similar results.
When I first got the car and did the oil, I used some pricey 0w30 oil as was recommended. Lifters ticked constantly, not that loud but always. Then I changed to Valvoline synpower 10w50 after reading that a workshop here uses 10w50 and it killed my lifter noise completely for the first 3-4,000 km. *Waits for oil nazi to come tell us both off about using viscosities not listed in service manual*

 

[rooks]

no shame in 10W-40/50 oil...i use HPR 10 for the VR4 and no lifter tick. most workshops that know the mitsubishi lifter issues will recommend slightly ticker oil and after owning the 6A12 and now a 6A13 i wont drop below 10w.

 

[Hotwire]

look out, you'll stir up the snake-oil (Amsoil) worshipers....

:lol: