Engine Warm-up time

Originally Posted by desertdriver

Dont confuse yourself with the synthetic vs petroleum oil arguements. Its all about hydrocarbon chain length and its relation to temperature dependent viscosity. All synthetic oils are hydrocarbons, just like petroleum based oils, they just have different polydispersity(better in synthetics). Think like a scientist not a lawyer. Molecular physics is molecualr physics, whether you pull the molecules out of the ground or synthesize them in a lab or plant the behaviors are consistent. the greater polydispersity of the mineral oils make them a bit better at lower temps.


Here is an article that compares the two if you care to read it. The (petroleum based)mineral oils actually lubricate better at low temps(thicker film before parts expand). this means that its even more important for synthetics to warm them up. Yeah, I used to be a metallurgist, so I know about expanding metals.

http://www.machinerylubrication.com/...?articleid=586

Don't argue with the science guy.

Originally Posted by desertdriver

the most critical apsect of warmup is the oil temp. this is because oil viscosity changes with oil temp. When the oil is cool, it does not lubricate your engine properly(its too thick), especially if you run it hard. BMW's use of the oil temp guidelines will help your car last longer by preventing you from running your engine hard under substandard lubrication conditions. With an engine that has such close tolerances(any finely engineered powerplant), the oil must come up to a sufficient temperature so it is not too thick to lubricate properly. Kudos to BMW for using a better way to help you take care of your car. If you ignore their recommendations, the risk is higher engine wear and shorter engine life. If you live in temps near freezing, it can take 20 mins or more to warm up your engine to the optimal operating temperature needed to run it hard if left out overnight.

It just kills me when on cold mornings, Sub 20 or so, I see people pull out of neighborhoods, etc. and just FLOOR it when I know the car has been running less than a minute. That poor engine...........

I hate to see that too.

But as long as the engine had enuf time to build pressure at all points the damage will not be as great as driving immediately before oil has gotten to all.

Originally Posted by Vanos4:12PM

It just kills me when on cold mornings, Sub 20 or so, I see people pull out of neighborhoods, etc. and just FLOOR it when I know the car has been running less than a minute. That poor engine...........

I have a friend who has a 328i, and he runs it pretty hard right after startup, and it doesnt get that cold here. He bought the car new and it burns oil, a quart every 3-4K. My 335 doesnt burn any oil at all. I have changed oil at 5k(1st), then at 7K intervals, and it burns no more than 1/4-1/3(7K) of a quart. this could be due to differences in break-in, but running the car hard at startup could also make the car burn more oil by increasing wear.

Yes.

Oil leaks thru the valve guides and by the rings, especially if not broken in right or revved too early or if the oil changes have been too far apart

For the people who think its ok to redline their car when its cold consider the M cars BMW produces. They all have a moving yellow/redlines which increases with engine/oil temp, I think if anyone knows the effects of WOT on cold engines its the BMW engineers.

Originally Posted by Vanos4:12PM

It just kills me when on cold mornings, Sub 20 or so, I see people pull out of neighborhoods, etc. and just FLOOR it when I know the car has been running less than a minute. That poor engine...........

We are a disposable society. For many folks, a car is simply a tool that is to be used for 3-5 years and then traded in for the next thing.

Originally Posted by Bavarian335

For the people who think its ok to redline their car when its cold consider the M cars BMW produces. They all have a moving yellow/redlines which increases with engine/oil temp, I think if anyone knows the effects of WOT on cold engines its the BMW engineers.

I'll take the word of the BMW engineers, they are alot more informed than any of us. Anyone who thinks they know more than the BMW design engineering team is a fool.

Originally Posted by desertdriver

i'll take the word of the bmw engineers, they are alot more informed than any of us. Anyone who thinks they know more than the bmw design engineering team is a fool.

+1

Originally Posted by AzNMpower32

We are a disposable society. For many folks, a car is simply a tool that is to be used for 3-5 years and then traded in for the next thing.

Unfortunately your are 100% correct. That is why I will never buy a used car again. There is much more behind the scenes that just Carfax that buyers will never know.

Originally Posted by vanos4:12pm

unfortunately your are 100% correct. That is why i will never buy a used car again. There is much more behind the scenes that just carfax that buyers will never know.

+1

The entire argument of conventional vs synthetic oils really cracks me up. As desertdriver pointed out, they are both hydrocarbon based lubricants.... But what you're missing is this: without DynoOil there is no "AmsOil".... Synthetic oil is simply a "more perfect" derivative of what would be created by standard refinement. Synthetic oil is the AHHHHNALD of conventional oil.

Originally Posted by desertdriver

Dont confuse yourself with the synthetic vs petroleum oil arguements. Its all about hydrocarbon chain length and its relation to temperature dependent viscosity. All synthetic oils are hydrocarbons, just like petroleum based oils, they just have different polydispersity(better in synthetics). Think like a scientist not a lawyer. Molecular physics is molecualr physics, whether you pull the molecules out of the ground or synthesize them in a lab or plant the behaviors are consistent. the greater polydispersity of the mineral oils make them a bit better at lower temps.


Here is an article that compares the two if you care to read it. The (petroleum based)mineral oils actually lubricate better at low temps(thicker film before parts expand). this means that its even more important for synthetics to warm them up. Yeah, I used to be a metallurgist, so I know about expanding metals.

http://www.machinerylubrication.com/...?articleid=586

1. Your statement that all synthetic oils are hydrocarbons is absolutely false. Many of the best synthetics are esters, diesters and polyesters, therefore they have oxygen atoms in the molecular chain, thus by definition they cannot be hydrocarbons.

2. The study you posted is about gear lubrication at high temps, not even a valid comparison to engine lubrication at low temps. Note the lowest temp tested was 50C or 122F. While I agree that there may be times that a mineral oil may be better than a synthetic the question is much more complex than that. There are many variables including the type of synthetic.

However, why don't you ask your engine if it is starting at 20 below zero if it would prefer a solid mineral oil frozen at the bottom of the crankcase performing no lubrication at all or a synthetic that is liquid and is actually being pumped throughout the engine and to the top of the cams. My friends that is where 80% of the wear on an engine takes place and where mineral oils fail severely compared to a good synthetic.

Originally Posted by 335i Driver

1. Your statement that all synthetic oils are hydrocarbons is absolutely false. Many of the best synthetics are esters, diesters and polyesters, therefore they have oxygen atoms in the molecular chain, thus by definition they cannot be hydrocarbons.

2. The study you posted is about gear lubrication at high temps, not even a valid comparison to engine lubrication at low temps. Note the lowest temp tested was 50C or 122F. While I agree that there may be times that a mineral oil may be better than a synthetic the question is much more complex than that. There are many variables including the type of synthetic.

However, why don't you ask your engine if it is starting at 20 below zero if it would prefer a solid mineral oil frozen at the bottom of the crankcase performing no lubrication at all or a synthetic that is liquid and is actually being pumped throughout the engine and to the top of the cams. My friends that is where 80% of the wear on an engine takes place and where mineral oils fail severely compared to a good synthetic.

+1 very good. I have been pushing about needing a bit of time for the oil to get to the farthest points, the cams.

Originally Posted by Vanos4:12PM

Unfortunately your are 100% correct. That is why I will never buy a used car again. There is much more behind the scenes that just Carfax that buyers will never know.

I too would not buy based on carfax alone.

Use a BMW dealer to give a complete exam to the car. Costs about $ 120. You will get a written report on official BMW paper. Its great for you and for negotiating the price down.

I've done this on all 3 of the BMWs I've owned and never had a regret. You don't have to buy a car while blindfolded.

Go ahead and buy new and feel good while taking the hit on immediate depreciation of $ 8-12K. Maybe you can throw that kind of money away. I can't and don't have to to get a fine used BMW.

Originally Posted by 335i Driver

1. Your statement that all synthetic oils are hydrocarbons is absolutely false. Many of the best synthetics are esters, diesters and polyesters, therefore they have oxygen atoms in the molecular chain, thus by definition they cannot be hydrocarbons.

2. The study you posted is about gear lubrication at high temps, not even a valid comparison to engine lubrication at low temps. Note the lowest temp tested was 50C or 122F. While I agree that there may be times that a mineral oil may be better than a synthetic the question is much more complex than that. There are many variables including the type of synthetic.

However, why don't you ask your engine if it is starting at 20 below zero if it would prefer a solid mineral oil frozen at the bottom of the crankcase performing no lubrication at all or a synthetic that is liquid and is actually being pumped throughout the engine and to the top of the cams. My friends that is where 80% of the wear on an engine takes place and where mineral oils fail severely compared to a good synthetic.

1) You apparently dont know the use of the word "absolute", check your facts. Mobil 1 is a polyalphaolefin, eg a "hydrocarbon" that is not fully saturated, and its just about the best performing synthetic out there because it isnt blended as much with mineral oil base stocks. Lesser, cheaper synthetics are made from alcoholic esters in a polymerization reaction and heavily blended with minearal oil basestocks, this is a cost control measure, over synthetics based on PAO of contolled polydispersity that are used in the better synthetics like mobil 1. Oh, by the way esters are hydrocarbons technically, oxygenated hydrocarbons to be precise. A pure oxygenated hydrocarbon oil would be very expensive as they are derived from vegetable oils. So in the end the esters or polyesters that are in synthetic oils are heavily blended with mineral oil components anyway.

2) On the low temp comment, what do you think startup is for the first 10 mins. No one ever said that synthetics dont do better up at high temps, they do and that is why BMW uses them. Not so some idiot nimrod can run his car hard just after startup.

3) Anyone who is starting their engine at 20 below zero, should get an engine block heater, put the car in the garage to keep it warm, or else suffer the damages. Yes the damages will be less with a mobil 1 type oil, but there will still be accelerated wear vs using an engine block heater.

To get back to the real subject here, synthetics do not alleviate concerns about running a car hard before warmup. Like I said before anyone who thinks they can ignore the BMW engineering recommendations is a arse, and I would never buy a car from them.


Anyone who is really interested here is an article on them:

http://www.viragotech.com/fixit/AllAboutOil.html

all oils have temperature dependent viscosity, eg, viscosity index. Mobil 1 is one of the best, and is a synthetic hydrocarbon. Its all about the oil polydispersity, not whether its a hydrocarbon or an ester.

Originally Posted by MARAUD

The entire argument of conventional vs synthetic oils really cracks me up. As desertdriver pointed out, they are both hydrocarbon based lubricants.... But what you're missing is this: without DynoOil there is no "AmsOil".... Synthetic oil is simply a "more perfect" derivative of what would be created by standard refinement. Synthetic oil is the AHHHHNALD of conventional oil.

Some people dont know that crude oil contains MANY components, like thousands different molecules. Motor oil(dino) just is basically a boiling fraction of the crude. Aliphatics, olefins, aromatics, yes even esters exist in crudes. Synthetics are better controlled in the chain length and functional group variations, so they behave more consistently with a range of temps, but this doesn not mean they dont have a temperature dependence or viscosity index.

I've read that synth is superior in cold starts to dino oil because it will cling to the part for 5or 6 days where the dino is 2 to 3 days max, same conditions.

The main and rod bearings in your engine are lubricated by a process called a hydrodynamic wedge. W/o going into the details this process drags the oil with the rotating component and raises the pressure to 8 to 10,000 psi in the bearing preventing metal to metal contact.

So when you motor is running the crank and the rods are supported by the wedge (that can be around 0.0008 thick) so no metal to metal contact occurs, even under the pressure of a cylinder firing.

But when the engine is cold and started there is bearing material to crank main and rod journals surfaces. There is metal to metal contact until the hydro-wedge is established. And that takes time for the oil to get to the bearings in sufficient quantity. So the better the oil clings the better it lubricates. This is why you should give your engine a minute to get the oil circulated before you put a load the 'dry' bearings.

Originally Posted by franka

I've read that synth is superior in cold starts to dino oil because it will cling to the part for 5or 6 days where the dino is 2 to 3 days max, same conditions.

The main and rod bearings in your engine are lubricated by a process called a hydrodynamic wedge. W/o going into the details this process drags the oil with the rotating component and raises the pressure to 8 to 10,000 psi in the bearing preventing metal to metal contact.

So when you motor is running the crank and the rods are supported by the wedge so no metal to metal contact occurs, even under the pressure of a cylinder firing.

But when the engine is cold and started there is bearing material to crank main and rod journals surfaces. There is metal to metal contact until the hydro-wedge is established. And that takes time for the oil to get to the bearings in sufficient quantity. So the better the oil clings the better it lubricates. This is why you should give your engine a minute to get the oil circulated before you put a load the 'dry' bearings.

the clinging of synthetic oil to metal surfaces is purported to be due to the polarity of ester functional group/and metal parts. the PAO's(mobil one and many others) are not polar, hence the explanation doesnt work there. my problem is that I want to see hard evidence that significant amounts cling to the parts, enough to provide a film. Molecualr polarity and the adhesion energies involved are quite low. Im not saying that some tiny amount might not cling, but to say it is sufficient to provide the necessary film thickness to prevent metal to metal contact is a claim that is made only by the manufacturers, and they have a vested interest to make that claim. Without some kind of independent validation it soiunds like exxon denying pollution from its refineries.

what can be said about the better synthetic oils is that they have lower pour points, meaning that oil is likely supplied to the surfaces in need of lubrication faster than dino oils. this means they will have smaller times where NO lubrication takes place.

In all this discussion oils, not additives are discussed. It is know that additives can stick to parts even better than esters, so the base stock of the oil might not be the only factor. Still starting an engine and running it hard are two different situations. As RPM goes up greater demands are made on the lubrication properties for a given temperature. Its obvious that this is a complex subject, and BMW engineers know their cars as well or better than anyone. If they recommend warming the car up before running it hard, they are likely right. Only a fool would disregard BMWs recommendation vs an oil manufacturers advertisement. After all the oil manufacturer has nothing to lose and is driven by the one upsmanship of advertizing, but BMW has a vested interest in taking care of their cars that they stake their reputation on. If your car wears out prematurely, the oil company will not be blamed.

[QUOTE=desertdriver;3640176]my problem is that I want to see hard evidence that significant amounts cling to the parts, enough to provide a film. QUOTE]

Woah there....woah

I did not say that amounts, sufficient to provide a lubricating film, cling to the metal parts.

I only stated that syn is purported to cling longer than non syn. I did not say anything about it being in sufficient quantity to lube. Only that it clinged longer by the days stated. And if true that is a good thing in itself.

It would be easy to test at home dipping samples in each lubricant and wait a few days to see what happens. One can feel the surfaces. Yes, this is not scientific and it does not prove anything other than possibly which maintains a film longer.

All vested interests aside, of course.

So, after all this discussion, what's the warm-up time on my 535i.

dj

Originally Posted by AzNMpower32

We are a dying society. For many folks, a car is simply a tool that is to be used for 3-5 years and then traded in for the next thing.

Your absolutely right.

[QUOTE=franka;3640232]

Originally Posted by desertdriver

my problem is that I want to see hard evidence that significant amounts cling to the parts, enough to provide a film. QUOTE]

Woah there....woah

I did not say that amounts, sufficient to provide a lubricating film, cling to the metal parts.

I only stated that syn is purported to cling longer than non syn. I did not say anything about it being in sufficient quantity to lube. Only that it clinged longer by the days stated. And if true that is a good thing in itself.

It would be easy to test at home dipping samples in each lubricant and wait a few days to see what happens. One can feel the surfaces. Yes, this is not scientific and it does not prove anything other than possibly which maintains a film longer.

All vested interests aside, of course.

But you forgot to consider that the source telling you this was basically an advertisement. I dont disagree with the idea, just whether it matters or significantly changes the startup wear. Now, the superior pour points of the better synthetics, thats straightforward, it will decrease wear on startup. And by the way the pour points were not an add, and I believe they are a quantitative fact not a subjective hypothesis.

Originally Posted by djfitter

So, after all this discussion, what's the warm-up time on my 535i.

dj

If you lease the car, do you care? If you bought the car the warmup time will be roughly proportional to your intelligence until the oil is warm.

Originally Posted by djfitter

So, after all this discussion, what's the warm-up time on my 535i.

dj

2.76 minutes at an ambient temperature of 32F. and 1200 RPM. There, feel better now?