What Weight Oil

[Dominic Toretto]

Do you use and why?

-Alex

[re-rx7]

Stick with 5w-20 or maybe 0w-20. Most wear occurs at startup all oils are to thick upon start up to properly lubricate. Oil at operating temp are pretty much the same density.

[Kaane]

I am running 5w30, most likely might switch to 10w40, I am running a paxton though.

[re-rx7]

Why 40?

[Dominic Toretto]

I am presenting the question because recently I called Westway and asked the service department what oil to use and they said 5W30. I didn't pay attention to the factory oil cap before calling so wondered why they would advise of something different.

-Alex

[kdanner]

Do you use and why?

-Alex


Joe Gibbs 0W. Because it is fast.

[re-rx7]

Joe Gibbs 0W. Because it is fast.

Pretty gd oil right there and gd weigh choice.

[Dominic Toretto]

Stick with 5w-20...

I was considering that, mainly to avoid any potential powertrain warranty disputes.

-Alex

[re-rx7]

Interestingly enough the Track Pack specifies like 20w-50. WHy IDK.

The thickness of moving oil is measured in centiStokes or cS. Most engines want the oil viscosity to be around 10 cS at normal operating temperature. The really thick multi-grade oils have a viscosity of 20 cS at operating temperature. One is not twice as thick as the other, it is only 10 cS thicker.

As we increase the heat from 212°F to 302°F the most commonly recommended oil thins from 10 cS to 3 cS. The thicker oil drops from 20 cS to 4 cS. Note that in a very hot engine the difference between the two oils is now only 1 – 2 cS. In other words they have about the same thickness. There is little advantage to a thicker based oil as a 20W-50 at very high temperatures. No, the 4 cS oil is not twice as thick as the 2 or 3 cS oil. This difference is almost insignificant.

The thing is most wear occurs at startup. All oils are to thick at startup to lubricate properly. As they heat up they all thin out to about the same specs.

The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct.

[Dominic Toretto]

The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct.

Very informative post, thank you. I don't think most people knew all of that information. In these cars it is impossible though, to figure out what oil pressure we have since the factory gauge doesn't give a reading in measurements of PSi... or any measurement for that matter. So we are forced to get an aftermarket gauge. But that's another topic all together.

I do have to ask though about the 10psi/1k rpm ratio. At operating temps at idle I would read 30psi at 800rpms with the LS1 using 5W30. With my 7MGTE at idle using 20W50 it would read just under 40lbs at 1,000rpm as shown here. Ignore the OU flip flops.
http://i80.photobucket.com/albums/j181/supraman90_2006/Aria/DSCF1202.jpg

So do you mean 10psi per 1,000rpm above idle?

-Alex

[re-rx7]

Very informative post, thank you. I don't think most people knew all of that information. In these cars it is impossible though, to figure out what oil pressure we have since the factory gauge doesn't give a reading in measurements of PSi... or any measurement for that matter. So we are forced to get an aftermarket gauge. But that's another topic all together.

I do have to ask though about the 10psi/1k rpm ratio. At operating temps at idle I would read 30psi at 800rpms with the LS1 using 5W30. With my 7MGTE at idle using 20W50 it would read just under 40lbs at 1,000rpm. So do you mean 10psi per 1,000rpm above idle?

-Alex

Exactly. So at 7000k rpm you'd want about 70 psi plus or minus. Ferrari uses a pricnicple of 75 psi at 6k rpm. I feel that that is a pretty gd measuring stick.Some people have tried this and occasionally get a somewhat low oil pressure while at idle. This is fine. There is no stress on parts at idle, the smallest oil flow will do the trick. It is at higher RPM where more BHP is produced.
The temperature of oil on your gauge is not as hot as it really gets. This temperature is an average with oil from different parts of the motor. Some parts are hotter than others. It is said that some of the oil gets as hot as 400° or 500°F in these racing situations.
Since the oil with a viscosity of 10 cS at 212°F thins to a viscosity of 3 cS at 302°F we will get more flow. The pressure will go down some as well. This is OK as long as we have a minimum of pressure to move the oil.

This increased flow will result in increased cooling by the oil. This is a good thing. You would probably want more oil flow in these situations and you get it. The hotter oil thins and this increases flow. The higher flow works harder to separate the engine parts that are under very high stress. It all works out for the better. Higher revving engines need thinner oils. You do not necessarily need to go to a thicker oil while racing. Only experimentation will tell.

[Dominic Toretto]

Here's a picture of the LS1 at idle and at 25mph. This is with the digital gauges but, you get the point. Each bar for the psi represents 10psi. Sorry for crappy pics.

http://i80.photobucket.com/albums/j181/supraman90_2006/Nicole/Crusin%20Pics/HPIM1707.jpg
http://i80.photobucket.com/albums/j181/supraman90_2006/Nicole/Crusin%20Pics/HPIM1705.jpg

-Alex

[Dominic Toretto]

The temperature of oil on your gauge is not as hot as it really gets. This temperature is an average with oil from different parts of the motor. Some parts are hotter than others. It is said that some of the oil gets as hot as 400° or 500°F in these racing situations.


Ah, very good to consider, had not thought about that. Guessing that is especially true for the oil going through the turbo.

-Alex

[re-rx7]

Here's a picture of the LS1 at idle and at 25mph. This is with the digital gauges but, you get the point. Each bar for the psi represents 10psi. Sorry for crappy pics.

http://i80.photobucket.com/albums/j181/supraman90_2006/Nicole/Crusin%20Pics/HPIM1707.jpg
http://i80.photobucket.com/albums/j181/supraman90_2006/Nicole/Crusin%20Pics/HPIM1705.jpg

-Alex40 psi at 25 mph is pretty nice. Oil may be a little thick but its ok.

Ah, very good to consider, had not thought about that. Guessing that is especially true for the oil going through the turbo.

-Alex

Probally even more extreme!!

[re-rx7]

The reality is that motor oils do not need to be changed because they thin with use. It is the eventual thickening that limits the time you may keep oil in your engine. The limit is both time itself (with no motor use) and/or mileage use. The storage of motor oil in your garage, particularly mineral based oils, slowly ages the oil limiting its use later. Do not store huge volumes of oil in your garage that is exposed to extremes of temperature.

Increasing the pressure while using the same oil will increase the oil flow but increasing the pressure by increasing the oil thickness will result in less flow. It takes more pressure to move a thicker oil. When you go to a thicker oil the pressure goes up because of the increased resistance, and therefore reduction of flow. Because the pressure is higher sooner, the relief valve cuts in sooner. Flow will actually be less when the RPM is up and the flow is needed the most.

10-20 psi at idle would scare the shit out of most people. LOL

[Bacadiesel]

Some cars idle at 5psi oil pressure and it's under manufacture spec. Once fully warmed up.

[re-rx7]

Some cars idle at 5psi oil pressure and it's under manufacture spec. Once fully warmed up.

Yup as oil warms its thins out.

[Dominic Toretto]

I knew my LS1 was on it's last leg once the oil pressure dropped to 20lbs at idle. There is definitely something wrong with that. Five years of 30lbs at idle and then seeing a 10psi drop plus the pressure at higher rpms was lower as well.

-Alex

[re-rx7]

These same rules apply to engines of any age, loose or tight. Just because your engine is old does not mean it needs a thicker oil. It will need a thicker oil only if it is overly worn, whether new or old. Yet the same principals of 10 PSI per 1,000 RPM still apply. In all cases you need to try different grade oils and see what happens. Then choose the correct viscosity. dID YOU CHANGE OILS?

[Dominic Toretto]

dID YOU CHANGE OILS?

No. The oil pressure changed all of a sudden while at 45%.

-Alex

[re-rx7]

That is odd.

[Dan12GT]

I'm on Amsoil 10w30. I chose to go with this oil because it isn't a huge leap from the recommended and most of the time it is pretty warm here in Texas so the slightly higher weight has it's advantages with heat. I've been on it almost 10k miles and am about to change and do analysis so I will share that here

[re-rx7]

I'm on Amsoil 10w30. I chose to go with this oil because it isn't a huge leap from the recommended and most of the time it is pretty warm here in Texas so the slightly higher weight has it's advantages with heat. I've been on it almost 10k miles and am about to change and do analysis so I will share that here

Weight has no adavantage with heat. They all thin to about the same when warm. Startup is where its crucial that 10w-30 is thicker cold then the reccomened 5w20. 0W-30 grade oil is not thinner than a 10W-30 oil. They both have the same thickness at operating temperature. The 0W-30 simply does not get as thick on cooling as the 10W-30. Both are still way to thick to lubricate an engine at startup.

The reality is that motor oils do not need to be changed because they thin with use. It is the eventual thickening that limits the time you may keep oil in your engine. The limit is both time itself (with no motor use) and/or mileage use. The storage of motor oil in your garage, particularly mineral based oils, slowly ages the oil limiting its use later. Do not store huge volumes of oil in your garage that is exposed to extremes of temperature.

When you drive that car down the road mid-winter in upstate New York or mid-summer in Florida the engine and oil temperatures will be around 212°F. But your Florida vacation is suddenly altered by a hurricane. You have to get out of Tampa, but so do a million other people. It is now 95°F and you are in a snarl. Everyone thinks they need a thicker oil for this situation. This is false.

[rriddle3]

...The reality is that motor oils do not need to be changed because they thin with use. It is the eventual thickening that limits the time you may keep oil in your engine. The limit is both time itself (with no motor use) and/or mileage use...
That and the amount of contaminates that get suspended in the oil over time, and the degradation of the anti-wear additives in the formula.

[re-rx7]

That and the amount of contaminates that get suspended in the oil over time, and the degradation of the anti-wear additives in the formula.

Yup thats what causes the thickening. I hate people that think if your oil isnt clean when drained its a bad oil cause it broke down fast. In reality a oil should be dirty because that means it is doing its job.

[Dominic Toretto]

That is odd.

I assume the bearing were going out, as well as some of the internal clearances and tolerances. The car was driven pretty hard on a daily basis for over 140k miles.

I'm on Amsoil 10w30. I chose to go with this oil because it isn't a huge leap from the recommended and most of the time it is pretty warm here in Texas so the slightly higher weight has it's advantages with heat. I've been on it almost 10k miles and am about to change and do analysis so I will share that here

Look forward to see the results.

-Alex

[DirtyD]

Track Pack cars are 5W-50

[re-rx7]

Track Pack cars are 5W-50

I know but dont know why

[Kaane]

I know but dont know why

They use 5w50 due to having 50% more antiwear additives. Highest levels of Zinc and Phosphorous. The weight of the oil is meaningless as you already mentioned it being almost the same at temp.

I will most likely swap to the recommended track car oil as well. All the 0w20 recommended oils have very low Zinc and Phosphorous levels to protect catalytic converters and other emission equipment.

for Example 0w20 mobil 1 has 650 PPM of Phosphorous and 750 PPM of Zinc.

15w50 Mobil 1 has 1200PPM for Phosphourous and 1300 PPM for Zinc.

5w50 is in between the 2.

[re-rx7]

Smh. You put that much through your cats amd you wont like it. Your talking like all that zinc and blah blah is gna protect your engine. Nope. That oil thick. Real thick. Your oil pressure will be higher because its like honey but will it lubricate better? No. I firmly believe in the 10psi per 1k rpm rule. You dont need a thicker oil just to race. You need to log oil pressure for that track and conditins to see what kind of weight you need. When tracking your car you nee to change the oil at 1500-2k miles anyway so those additives arent really important. In diesels that use this oil and are a completely different make up it beneficial as they may see 15k between changes.

With winter approaching that oil will be extremely hard on the motor at start up but its your car.

[Kaane]

I am taking my cats out :)

Oil pressure is important but HTHS rating is more important to me. 0w20 mobil 1 has a HTHS rating of 2.61, most good racing oils have HTHS rating of 4+

I'd run motul 300v if I could, but it's too damn expensive.

0w20 oils shear too much with temp and their ZDDP levels are just too low when I am making 800hp.

Ford puts 0w20 because that is what gives them best economy and they are restricted to oil that have 800ppm of ZDDP or less.

[re-rx7]

Almoat all wear is at startup. 0w-20 shears to much? Link to where that is stated? All oil at 212f are almost the same viscosity. So why would it shear? Oil pressure is everything. I mean everything. What makes the diff is startup. Only logging will tell what oil you need to use.

[re-rx7]

Interestingly enough the Track Pack specifies like 20w-50. WHy IDK.

The thickness of moving oil is measured in centiStokes or cS. Most engines want the oil viscosity to be around 10 cS at normal operating temperature. The really thick multi-grade oils have a viscosity of 20 cS at operating temperature. One is not twice as thick as the other, it is only 10 cS thicker.

As we increase the heat from 212°F to 302°F the most commonly recommended oil thins from 10 cS to 3 cS. The thicker oil drops from 20 cS to 4 cS. Note that in a very hot engine the difference between the two oils is now only 1 – 2 cS. In other words they have about the same thickness. There is little advantage to a thicker based oil as a 20W-50 at very high temperatures. No, the 4 cS oil is not twice as thick as the 2 or 3 cS oil. This difference is almost insignificant.

The thing is most wear occurs at startup. All oils are to thick at startup to lubricate properly. As they heat up they all thin out to about the same specs.

The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances. For some reason very few people are able to get this simple principal correct.

Again.

[Kaane]

So why would ford put 50w oil in their track pack cars? I mean according to your logic the oil would shear the same and have the same oil pressure.

Why do all racing oils have high temp shear tolerance? Why do they have high ZDDP content? I mean if it was all fluff. Everyone would be running 0w20 oil.

Look at Porsche recommended oils and Nissan GTR.

0w40 or 5w50.

For normal street driving on non modified engines I am sure 0w20 is more than sufficient, but for track application or supercharged engines extra protection is warranted.

[re-rx7]

See that zero 40?

[re-rx7]

Log back into this in the morn. Im on my phone but i eill answer that question.

[re-rx7]

So why would ford put 50w oil in their track pack cars? I mean according to your logic the oil would shear the same and have the same oil pressure.

Why do all racing oils have high temp shear tolerance? Why do they have high ZDDP content? I mean if it was all fluff. Everyone would be running 0w20 oil.

Look at Porsche recommended oils and Nissan GTR.

0w40 or 5w50.

For normal street driving on non modified engines I am sure 0w20 is more than sufficient, but for track application or supercharged engines extra protection is warranted.


The best situation as described by Ferrari is to use the 0W-40 around town and the 10W-60 “racing oil” on the track. It has to be that “hot” track though. A compromise situation would be to use the 5W-40 for both but this may not be optimal. Certainly, if you are just an urban driver as me use the 0W-40 or even a thinner oil as I do in my stanger. Again, I used the 0W-20 grade.

FYI. The Formula 1 cars that run at 15,000 RPM and higher use straight 5 and 10 grade oils.


This increased flow will result in increased cooling by the oil. This is a good thing. You would probably want more oil flow in these situations and you get it. The hotter oil thins and this increases flow. The higher flow works harder to separate the engine parts that are under very high stress. It all works out for the better. Higher revving engines need thinner oils. You do not necessarily need to go to a thicker oil while racing. Only experimentation will tell.

he temperature of oil on your gauge is not as hot as it really gets. This temperature is an average with oil from different parts of the motor. Some parts are hotter than others. It is said that some of the oil gets as hot as 400° or 500°F in these racing situations.

Now Ford I would say reccomends the thick oil because the cars are sold everywhere from hot as hell places to frigid. The Hot as hell places are probally the concern then there maybe some benefit to a thicker oil. Now with racing oils the aditives you speak of dont actually kep the oil from shearing, It still shears but the difference is those additives are the last line of defense when it happens. The bad thing is most racing oil clog cats and coat engien parts so 1-2k mile changes are a gd idea.

[rriddle3]

I inderstand and generally agree with the gist of your explanations, but I will say that for the majority of us who drive our Mustangs on the street with the occasional run on the track or course, that following Ford's oil recommendations will serve us just fine. Modern commercial oils are so much better than they were years ago that the selection process has been simplified for all of us. :gr_grin:

[re-rx7]

I inderstand and generally agree with the gist of your explanations, but I will say that for the majority of us who drive our Mustangs on the street with the occasional run on the track or course, that following Ford's oil recommendations will serve us just fine. Modern commercial oils are so much better than they were years ago that the selection process has been simplified for all of us. :gr_grin:

Very very very true. 5w-20 is the pefect oil for most all of us. I use penn Ultra but there really isnt a bad oil anymore.

[2012mustang76123]

I have the extended bumper to bumper warranty. Always take it to the dealership. Just in case it becomes an issue The dealership handled everything related to maintenance besides brakes.

[Bacadiesel]

If you are running your car at the track is severely shortens oil efficiency.

[re-rx7]

If you are running your car at the track is severely shortens oil efficiency.
That depends on alot of different factors.

[Bacadiesel]

Racing all day would require an oil change.

[re-rx7]

obviously.

[Bacadiesel]

You're so smart re-rx7

[re-rx7]

I can haz smert?

[virtu]

Picked up a case of Motorcraft 5w50 and an oil filter yesterday from the dealership yesterday on the way home from work. This will be the 3rd oil change I have performed since purchasing the car. Would consider switching over to Redline as I have been using their oils in my cars and motorcycles for many, many years. However, I do feel the Motorcraft 5w50 is very good based on some of the research I have done.

https://lh6.googleusercontent.com/-IXapSasdffc/UlRnBzs6PDI/AAAAAAAARUc/Aov1CLYu7rM/w408-h306-no/13+-+1

[re-rx7]

Ford doesnt make a bad filter either. Few years back their brake fluid was as good as some race fluid.