10W-30 or 10W-40 for winter?

[HondaDustR]

I have successfully gridlocked myself from being able to decide what to put in the car for the winter. Technically, shouldn't 10W-30 and 10W-40 have the same cold starting properties? I can't decide which one to buy in keeping with using Brad Penn. It makes sense to just use 10W-40 if the cold starting properties are the same, but I have noticed oil temps run lower, down around 140-160 degrees, with it being cold outside and take much longer to warm up. Any slow moving traffic will bring the temp up to 180 fairly easily, though. I have a feeling it's going to be a cold winter, too. I may actually just run some Rotella T 5W-40 synthetic if I can find some, since it's a bit cheaper and more available than Brad Penn and times have turned much much tougher over the last couple months being in full time school. Additive package sucks, being an API SM oil, but oh well...It's still better for the valvetrain than, say, diesel fuel. If anyone has any other ideas, I will not even consider any Mobil1 oil or any straight conventional oil, and it can't cost more than about 5 or 6 bucks a qt. Rotella T is still pretty good stuff and it's what I was running until it went to API SM and I found Brad Penn. Problem is, Brad Penn doesn't make a 5W oil, and their oil is part synthetic, making it a bit thicker in the extreme cold.

Any thoughts?

[962porsche]

the 10W is the same ( cold cranking )10W 30 0r 10W 40 after that its the up to temp running weight . just how cold will the weather you will be driving in ? only you will know that for an average winter temp !

[romad]

Its amazing to me how much stress oil causes relating to these cars. The quaility of the oil compared to what it was when these cars were designed is light years better , at all grades and brands. Even the manual suggest 10w-30 and 40's at 15000 mile oil chg intervals.
If you change oil at regular interval of say 3000 to 7000 miles, any brand outside of maybe some acme brands, is going to be just fine. As for synthetic or synthetic blends they are all good compared to what was..........If you are driving around town with an occasional trip around red line, any name brand is going to be just fine, stop the maddness.

[wild man]

All-in-all, I do agree with the last post. But, for those who are hopelessly hooked on the madness of it all, put this one in your pipe and smoke it:

I recently saw a TV commercial, put out by the castrol motor oil company, for a new engine oil formulation that they just came out with. I now can't recall the name they gave it (someone help me out here), but they are making what I consider to be a pretty outrageous claim. They state that it only allows 1/8 (that's almost a full order of magnitude!) of the engine wear that occurs with Mobile 1. With all of the mobile 1 fans that seem to be out there, this has GOT to be the deal breaker! Yes, no, maybe?

I have never been much of a castrol fan myself, but this would appear to change everything. I just wonder how much zinc phosphate it contains?

[guru944]

Fellow Porsche drivers:
Recommend 10w-30 Synthetic Pennzoil Ultimate/Platinum or AMSOIL 10w-30 HP. These are the real "Proven Standards out there" since 1986. Even better than the most commonly available Mobil-1 Synth Blends. Penn is recommended for the older pre 1985 vehicles that really require more zinc D. phosophate stuff but i still would not use it. However that "stuff" clogs up Oil filter just like PTFE/teflon (remember the 1980's hype), O2 sensors and Catalytic converters 70-80% of the time on the later emission vehicles like the 944, 968, 911's, 928, Etc.
Recommend stepping up to the better engineered Lubricants(Pennzoil (blended leader) or the 100% industry reference Synthetic brand AMSOIL.
Rotella is also a good lubricant brand for conventional oils.

Check out "You tube" for some of this info, its "REAL"

Hope this post was helpful.

Later...

[89-944NA]

Valvoline VR-1 Racing, it's the only conventional oil we use at the shop, and in the race cars, but then, we are in SUNNY (it was 87 here Monday) Southern California, where we can race and drive our beloved cars year round

[HondaDustR]

Well, if it says API SM on the bottle, it automatically can't have more than 800 ppm of phosphorous, period, end of story...which is about 400ppm too litle for our motors. Screw the damn cats. I'll just replace it when it eventually dies, and my car is old enough that it doesn't have to test on the dyno for emissions, anyway. Mobil1 is just crap for these cars. The SM rated 0W-40 got dismal ratings for ZDDP in some UOA results, and a few other numbers weren't too good either. There's so much crap out there that just shears out under high heat too easily. The Pennzoil synthetic is probably good, and most anything Amzoil makes is excellent, although it's always expensive and nearly impossible to find off the shelf anywhere.

Rotella is available in synthetic, and in 5W-40. The other plus is I can usually find it at walmart, which means it only costs about 4 or 5 bucks a quart. I like the 5W idea. It gets fairly cold around here lately, in the 20's and was in the mid teens last night. A few years ago, you'd be lucky to see freezing overnight in January. Cold starting is where the most wear and damage is done by far for a well maintained engine.

I do keep hearing about the VR1, but never see it on the shelves anywhere. The problem with it is I assume it is a race formulation needing short drain intervals. I don't really want that with a daily driver, and conventional turns to syrup in the cold. And thank God I'm not in CA...the environmental Nazi state.

I just can't stand all the EPA manipulation and the mandate this and the regulate that. Solving problems with problems. The oil technology has come a long way, but so has the EPA. I like to drive my car, not putter along trying to make some crap econobox go the distance.

[wild man]

Originally Posted by HondaDustR

Cold starting is where the most wear and damage is done by far for a well maintained engine.

I do keep hearing about the VR1, but never see it on the shelves anywhere. The problem with it is I assume it is a race formulation needing short drain intervals. I don't really want that with a daily driver, and conventional turns to syrup in the cold. .

Advance sells the VR1. But I quit using it for the reasons listed. I go 5K between oil changes (I don't race the car). The price of the stuff has also gone up considerably. I'm now running Brad Penn 20W-50, as I can get it for $26/case. Since I regularly use engine treatments, the cold starting wear issue is negated, and I also have a certain level of protection, should I happen too loose oil pressure. But the 20W-50 makes the car take forever to warm up in the wintertime. Is there a good 5W-50 synthetic out there, which HAS the higher levels of ZDDP in it? I'm not into having to change my oil 2wice a year.

[racer]

You could check the owners manual as it makes recomendations based on weather. 10/30 would be fine. I put 10/40 in mine for the winter and either 15/50 or 20/50 in the summer. I personally fear a 0 or 5 weight oil is too thin (fine for new motors, but not 20+ year old motors) and will end up leaking through seals and onto my garage floor

[HondaDustR]

Originally Posted by racer

You could check the owners manual as it makes recomendations based on weather. 10/30 would be fine. I put 10/40 in mine for the winter and either 15/50 or 20/50 in the summer. I personally fear a 0 or 5 weight oil is too thin (fine for new motors, but not 20+ year old motors) and will end up leaking through seals and onto my garage floor

I always puzzled over the numbering systems myself because the 20 weight cold 50 weight hot just seemed to defy physics. Well after years of puzzing, I think the right explanation just dawned on me yesterday. The "W" number is the viscosity the oil behaves like when cold and the second number is the viscosity it behaves like when at operating temp. Nothing new there. But it's impossible that a 20W-50 is thinner when cold than warm, going by just that. What I believe is actually going on is, when the oil is cold, it is the consistency of a standard 20 weight at the same cold temp. When it heats up, the polymers fold/change shape to take on a new viscosity, making the oil have the consistency of a 50 weight, but only in the hot end of the viscosity/ temp curve. This simply means it's less thick when cold and less thin when hot than say a straight 30 weight oil (the marvels of modern chemistry...car nuts in the way back good old days probably would have peed themselves at the though of such a miracle oil). So a 0W-40 will not leak past engine seals like water as it might sound, because the 0 only applies when cold and will be as thick as a straight 0 weight when cold and only when cold, which is still thick to some degree in comparison to a 30 or 40 (and maybe even a 50) weight oil at operating temp. At operating temp, you would theoretically not be able to distinguish it from a 5W-40, 10W-40 or a 15W-40 also at operating temp, but would be noticably thinner than all three at cold temps. So a 0W-40 should theoretically be an excellent choice for cold starting and a 10W-30 and a 10W-40 should be virtually indistinguishable at say 30 or 40 degrees. Also, theoretically, if your motor does not leak when hot, there's a snowball's chance in hell it will leak cold, barring the effects of thermal expansion/contraction and other factors unrelated to oil viscosity. Most oil leaks just leak, end of story (until you get to synthetics, but that's more an issue of smaller molecular size and its cleansing effect on pre-existing varnish that had been keeping old seals from leaking).

The viscosity modifiers required to give the oil this property are very large, complicated polymer chain molecules much like proteins and are suceptible to breakdown from heat and extreme shearing loads. An oil "shears out" when the modifiers are physically torn apart and as a result the oil thins at operating temp (I have noticed Brad Penn 20W-50 do this to some degree...I've heard it's an inherent problem characteristic to 20W-50's and is difficult to avoid). Heat breaks them down and the oil thins. I have observed it first hand on whatever cheap oil the PO had in the car when I bought it. Not too many miles into my ownership, the running oil pressure degraded from about 4.5 bar to around 3.5 bar. A fresh change of oil fixed it instantly. Higher quality base stocks need less modifiers to get the viscosity temp range, especially for previously difficult ranges to produce such as 20W-50, making the oils more durable and more protective (Brad Penn). Synthetics can be engineered from the ground up to have the desired multiviscosity properties and require little to no modifiers, making them extremely resistant to heat breakdown and sludging (when the modifiers turn to complete goo and percipitate out of the oil). That's why we now see modern oils such as 0W-40 that can also last 5000 miles with no problem. This is also one of the primary benefits of synthetic oils. My dad was telling me about the old school conventional 20W-50's from the 70's and 80's and how they started out thick and seemed to turn to water in a heartbeat in those old tired cars that they were usually used in. Sludge was a huge problem back in those days. One reason why 3000 miles had been the standard everyone knows so well that now is a bit short for modern oils.

wild man, what engine treatments are you refering to that you think works, just out of curiosity. Any research I have ever done on any of them seem to quickly converge on the idea that they're all snake oil. Many of the claims are pretty far fetched. It seems like most of the good european brands not sold here have all sorts of good viscosities like 5W-50, 10W-50, 15W-60, and many more 0W-40 selections than what is commonly available around here. Most "normal" cars in the US (ie non deisel, non sporty, boring, overpriced any and/or all of the above) have no need for the more exotic viscosities.

[wild man]

That was quite a long post. My attention span had some difficulty dealing with it. It's very comprehensive though. What you have to keep in mind is that 5 weight oil is still going to be way thicker at "W" temps than 50 weight is going to be at high temps.

I know I am in the minority when it comes to believing in engine treatments. I typically switch back an forth between duralube and one that is teflon based, such as slick 50. What really sold me on them was the time when I blew a external oil cooler hose and didn't realize it until several miles later, when the engine was pinging like crazy and didn't have any power left in it. It was only then that I saw that I had no oil pressure, pulled onto a side street and shut it down. After I replaced the hose and refilled the crankcase with oil, it ran as it did before, seemingly without the slightest hint of any engine damage. My neighbor was sold on them when he changed the oil in his older ford pickup truck and added a quart of duralube. It was the first time any sort of engine treatment was used in it. After the oil change with duralube, the idle speed went up, and he had to adjust it down, to get it back to where it was before.

[HondaDustR]

Originally Posted by wild man

That was quite a long post. My attention span had some difficulty dealing with it.

Haha...yeah, I've been stuck at school with nothing to do but a statistics take home final.

Well, it's interesting when people actually have real experiences that suggest some of those additives actually do something. I'm sure most people are skeptical because it's hard to quantify any benefits. Some guy that has a ford powerstroke specialty shop out in Georgia that sees alot of really hard run trucks swears by prolong. He definitely knows his stuff on those motors and sees alot of tuned stuff, too. Definitely not just pushing the brand, and I'm tempted to give it a try. Do a search on youtube for powerstrokehelp.com if you need something to kill time with, find diesel motors fascinating, and/or actually own one. Personally, if I could have a duramax 6.6L in a sports car, I would be in heaven.

Zmax also sounds interesting, especially after learning about interstitial diffusion in material science, ie the theory on how zmax works is actually possible. They were sued for false claims, but I think it was eventually thrown out. The problem is most of them aren't exactly cheap. Awhile ago I got a gallon of lucas oil stabilizer (the thick syrupy stuff), found out it was just thick petroleum base stock, and took it right back. No magic additives to be found.

[wild man]

I hated stats! Not really being a person who gets off on math, I actually liked calculus, DE's (of the mathematical variety), and transforms, better.

Although I have never used prolong or zmax, probably because they are the higher priced ones, I have no problem in believing that they work, if the lower priced ones work.

As for the lucas oil stabilizer, I actually do have a gallon of it myself. Although lucas is a pretty respectable name when it comes to petroleum products, THAT STUFF IS NOT AN ENGINE TREATMENT! It is an "oil" treatment. There is a BIG difference - engine treatments treat the metal surfaces inside of the engine that contact each other. They DO NOT treat the oil. Treatments such as the lucas product help the oil itself last longer before breaking down.

[pjs77]

Sorry guys, but I am a total rookie on this subject. I understand the concepts and what the different viscosities do, but it's still a little confusing to me. I have an NA w/ 156k miles and I live in the Northeast. I think the PO was running Castrol Syntec 5W-50 full synthetic. But I'm not sure. I continued to use it and now all of a sudden I have front crank seal leak. Now I hear all this about 10w-30 and I have no clue on what I should be running. The car may get used a few times during the winter but only to strech its legs or to get some work done on it.

Any advice would be great, short and sweet. I can't do the 1000 word essays

[wild man]

Seals sometimes do start to leak, especially if they have many miles on them, so there is no need to get bent out of shape about it. Just put a new one in, and be done with it. With the miles you have stated, you should also put in a new oil pump drive sleeve, because it probably has a pretty decent sized wear groove in it. You might also want to consider new belts, rollers, and other front seals, while you are in there. Welcome to: "it starts adding up pretty quickly".

Other than seal leakage, the 5W-50 synthetic should not have hurt the engine.

[pjs77]

Originally Posted by wild man

Seals sometimes do start to leak, especially if they have many miles on them, so there is no need to get bent out of shape about it. Just put a new one in, and be done with it. With the miles you have stated, you should also put in a new oil pump drive sleeve, because it probably has a pretty decent sized wear groove in it. You might also want to consider new belts, rollers, and other front seals, while you are in there. Welcome to: "it starts adding up pretty quickly".

Other than seal leakage, the 5W-50 synthetic should not have hurt the engine.

Thank you. I kind of figured that. But reading all the posts on here I just had to ask.

I am ordering a kit today actually. It comes with the TB and a new water pump, gasket, thermostat, timing belt, balance belt, oil cooler gasket kit, front engine seal kit,all 4 rollers (all new parts and all for $560!). This just after I put new Koni sports and vented rotors on 2 weeks ago, it does indeed add up quick. I'll throw the sleeve in too while I'm in there.

[wild man]

Take extra care if doing the oil cooler seals. From what I understand, that is a job that can be somewhat "tricky". (hand me a 7-up, dave)

[guru944]

Its 25' today in New York. That's too cold for any 10W-40 weight motor oil on any 4 cylinder engine.
Facts to remember some basics:
Weight vs Mech Energy
10w-30 400cs (centistrokes)
10w-40 750cs 1.75 x 10w-30 force required
20w-50 1000cs 2.5 x 10w-30 Force required.

How much force and time will (F=Ma) it take for your oil pump to flow enough motor oil up into your cylinder head where 75% of the heat energy is generated/located? to effectively protect your Valve seals, Cam(s), Lifters and all other vital moving parts, engine especially when you cold start?...Humm...

What about heat transfer?

Definition: Viscosity- resistance to laminar fluid flow.

"Open your minds"

Later,

[redranger]

was using 15w-50 in my 968 and had some ticking, usually when car was cold, maybe from lifters. The other day switched to 0w-40 and the ticking is completely gone. Only had the car since May and had been using 15-50, but with this switch, this is the quietest the car has been.

I'm located in NJ and temps were below 20 this morning.

[HondaDustR]

I stumbled upon some German castrol syntec 0W-30, so I'm happy. FAQ - GC ( German Castrol ) - Bob Is The Oil Guy

It is supposedly not a cheaper group III hydrocracked "synthetic" like the US made syntec.

Oh, it also helps to do a bit of research, too. Bob the oil guy's motor oil 101 chapters are pretty informative and I got alot of minor details that make all the difference out of it. Welcome

One major problem with running a thicker oil that I was not aware of before I read the article is that both pressure AND flow are important! Pressure is pressure regardless of viscosity, but higher viscosity is more resistant to flow, requiring higher pressure to get the same amount of flow. Flow is what cools the bearings, especially at high rpm, and wear is also directly related to heat. When you run a heavy oil, especially when it's cold out, the OPRV pops off much sooner, since it is pressure operated only. You get pressure to come up quickly on the gage, but flow stagnates as well, since the rest of the flow is running past the OPRV back into the sump. A perfect scenario would have the pressure ramp up with rpm and have the OPRV pop off just as the rpm peaks, popping off at a pressure of typically around 10 psi x rpm/1000. This is actually pretty consistent with the factory spec of 4 bar at 5000, since 4 bar equals about 58 psi. I see 4.5 bar at redline, meaning it still adheres to the "rule", but the fact that now the OPRV pops off at 2000-2500 rpm running 20W-50 at operating temp, means that flow is constant beyond that speed and at a lower value than say a 40 or 30 weight oil for the rest of the rev range. It gets complicated with modern oils, because they don't break down and thin like the oils 20 years ago did when Porsche was recommending oil grades, as well as having better shear strength and boundary lubrication properties.

I will try the 0W-30 and see how it works. I broke my motor in on 30 weight and 10W-30 conventional oil, and did not have any oil pressure problems, other than it took more revs to pop the OPRV open. Now I know why and why it might actually be a good thing as long as it continues to adhere to the 10 psi/1000 rpm rule. Higher pressures do not really translate into higher film strength in the bearings. The need to use heavier oils comes from increased tolerances in the bearings due to wear, making it more difficult to develop enough pressure.