Which more accurately reflects cold performance?

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2,352
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Southwest Virginia
Both are important, but I would put more weight on the MRV, especially in Montana winters. CCS relates to the ability of the oil pump to suck cold oil from the oil pan and push it along through the engine (higher shear rates). This creates a "hole" in the cold oil in the pan. MRV relates to the oils ability to flow back into the hole under its own weight (lower shear rate). If the oil cannot flow back into the hole the pump will suck air, sort of like sucking Jello through a straw - you create a hole that the Jello cannot refill. The ability of a cold oil to flow under its own weight is subject to a lot of chemical and physical variables. Personally I would have more faith in the ability of the oil pump to have spare pumping power than I would trust the oil to flow fast enough to fill the hole. Tom NJ
 
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744
Location
SW Missouri
CCS (Cold Cranking Simulator) viscosity and MRV (Mini Rotary Viscometer) viscosity measure different aspects of an oil's cold performance. According to the ASTM, "The CCS apparent viscosity of automotive engine oils correlates with low temperature engine cranking. CCS apparent viscosity is not suitable for predicting low temperature flow to the engine oil pump and oil distribution system." The MRV test measures the pumpability of oil. So, both tests measure aspects of cold temperature performance. IMHO, the MRV test is the more meaningful of the two. Of the two oils you mentioned, the Citgo oil will give much better cold weather performance. There is little difference between the CCS viscosities (6240 vs 6100). But Citgo's MRV of 16,900 is much lower (better) than the Purus MRV of 44,500. That's part of the reason why the Purus is cheaper.
 
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6,388
Location
Washington St.
So, at what temperature is it smart to put a heater on the oil pan as well as in the cooling jacket?...and maybe also on the battery. Very cold starting of an engine results in accelerated engine wear. Just because the engine will start is no sign that you are doing the best for longest (and most economical) engine life. I'm used to preheating all industrial engines for both the rapid start and best reliability, both short term and long term.
 
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744
Location
SW Missouri
Well, as has been discussed here many times, all motor oil is too viscous at all ambient temps, even 110F. That being the case, it wouldn't hurt to use an oil heater year-round.
 
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10,146
Location
Burlington, Ontario, Canada
-You haven't mentioned a what temperatures you will be actually starting your vehicle? -What is the vehicle and do you really need a 40wt oil? -Is the oil really that cheap; under 5 bucks per quart to warrant not going with a 0W-40 like M1 0W-40 (on sale) which has far superior cold temp performance?
 
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28,123
Location
Regina, Saskatchewan, Canada
Originally Posted By: Ken2
So, at what temperature is it smart to put a heater on the oil pan as well as in the cooling jacket?...and maybe also on the battery. Very cold starting of an engine results in accelerated engine wear.
In my view, the oil pan heater use depends upon which viscosity I'm using and the general ease in dealing with the oil pan heater itself. If I'm using a good winter oil, I worry less. However, since this is the diesel forum, I'll try to be a little more rigorous. Not everyone is using a 0w-40 HDEO. Ideally, I like to use an oil pan heater when the temperature drops below, say, -25 C. Bump that up to -20 C if you're using a 10w-30 HDEO and even higher if running 15w-40 all year round. However, as was pointed out, even room temperature oil is "too thick" so there's no harm in running an oil pan heater at warmer temperatures. I think a permanently mounted oil pan heater is a great idea. For the block heater, I prefer to use them below -15 C, be it diesel, gas, or propane. As a side effect, it certainly helps clear the windows and get the heater going sooner. I don't approve of battery blankets. Heat is a big enemy of batteries and people generally leave the things on all year, rather than take them off in the spring. There are a few permanent mount automatic maintainers available. In my old truck, I use a Solar brand permanent mount. When the battery cools in the dead of winter, voltage drops, so the charger kicks in, warming the battery and increasing voltage, then cuts out, and so forth. Cranking performance is improved far beyond what I've ever seen a battery warmer accomplish. The charger has no detrimental effect on battery life, and probably has the opposite effect. The last battery in my F-150 lasted ten years, and that's with winters going below -40 C to summers in the neighbourhood of +40 C.
 

chevrofreak

Thread starter
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4,942
Location
Billings, MT
Originally Posted By: CATERHAM
-You haven't mentioned a what temperatures you will be actually starting your vehicle? -What is the vehicle and do you really need a 40wt oil? -Is the oil really that cheap; under 5 bucks per quart to warrant not going with a 0W-40 like M1 0W-40 (on sale) which has far superior cold temp performance?
The oil would be for a friends Ford F550, and Montana winters regularly get down to -30F or lower. Yes, I get the oil stupidly cheap. I can't mention the price, but the Purus costs about as much as most people would pay for a gallon of name brand 15w-40 at regular price at O'Reilly.
 

dnewton3

Staff member
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8,599
Location
Indianapolis, IN
I seriously doubt there is going to be that much difference in the actual wear, at least to a point where total overall lifecycle of the engine is going to be affected. We BITOGers are overly concerned about most lube related things, where the realities of life get missed because we seek the absolute best (however that is defined by each individual), and yet the vast masses go on down the road with no cares and little worries. My point is that the cold start protection afforded by these two PAO products you inquire about is pretty darn good, and I seriously doubt you'd ever see a manifestiation of wear metal difference if you did some UOAs. Even if there were a difference, it would not alter the vehicle lifecycle enough to warrant concern; there are VERY few people that drive a vehicle out to 400k or 500k, which is where the wear from those decades of starts might actually show a difference. A Ford F-550 could have, depending upon year, a 7.3PSD, a 6.0, a 6.4, or a 6.7, so you really haven't told us a whole lot. (Actually, I suppose we could even include the 6.8L gasser, but I'll presume it's not ...) Does not really matter. If you can get one of those oils on the cheap, either will do a great job. Use them for the diesel engines. Or, you can get a good 10w-30 or 5w-30 HDEO. In short, don't over-think this because the engine isn't going to last forever, or die next year, based upon the choice. Use a block heater (probaly came with one) and add a battery trickle/maintenance charger for good starts. Heat the pan if you choose. If you're THAT concerned about it, where wear avoidance is THE MOST IMPORTANT issue, then I'd use a 5w-30 PAO HDEO like Amoil or Castrol. But I suspect that price is a contributing issue, because you can get the 5w-40 oils "stupidly cheap". In that case, pick one don't worry.
 
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chevrofreak

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4,942
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Billings, MT
Originally Posted By: chevrofreak
Originally Posted By: CATERHAM
-You haven't mentioned a what temperatures you will be actually starting your vehicle? -What is the vehicle and do you really need a 40wt oil? -Is the oil really that cheap; under 5 bucks per quart to warrant not going with a 0W-40 like M1 0W-40 (on sale) which has far superior cold temp performance?
The oil would be for a friends Ford F550, and Montana winters regularly get down to -30F or lower. Yes, I get the oil stupidly cheap. I can't mention the price, but the Purus costs about as much as most people would pay for a gallon of name brand 15w-40 at regular price at O'Reilly.
Looking at O'Reilly's joke sale prices, I can get it even cheaper than their Delo 15w-40. I don't know what engine it is, I just know it's a F550 with a diesel that sees some hard use, even in winter. I don't want him to have to run a block heater all the time, and I don't want him to have to change oils when the weather starts getting warm.
 

dnewton3

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8,599
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Indianapolis, IN
Choose what you see is fit. One note about the temps. Do not confuse windchill temps with ambient temps. I seriously doubt your friend see's temps "regularly get down to -30F or lower." Windchill down that low; sure. But ambient temps? No. Here is a short list of average low temps (according to weather.com in deg F): Billings: +15; Sun Burst: +8; Eureka: +18; Butte: +6; Malta: +3; West Yellowstone: -1. Heck, most of Montana doesn't get any colder for an average low than does the central midwest. I could not find a place in MT that get's "regularly down to -30F" or below. Billings in particular is really no colder than Indianapolis for average lows. My point is that windchill temps do not affect equipment for start up temps. Windchill is a concept that approximates a perceived temperature that humans feel when the evaporation of moisture is happening on our skin. That does not affect a dry engine block or oil pan that sits in a driveway or parking lot. Ambient temps are all that you need to be concerned with when it comes to cold engine starts. I seriously suspect that any decent 10w-30 HDEO would do fine, either in dino or semi-syn. I run dino 10w-30 year round in my Dmax. It survives all the punishment I can dish out, even with summer heavy towing out west. My neighbor has used the very same dino 10w-30 in his 6.0 PSD with good UOA results as well. You have the ability to get some fine fluids (PAO 5w-40) for the same price as others get "normal" oil at retail. That's great for you. But the general average low temps in MT do not necessitate syns, overall. I am not saying your friend should use a dino 10w-30; you have a great opportunity to capitalize on some fantastic deals on some premium oils. Good for you both. But I don't want other people reading this thread to come to some false conclusion that ONLY syn's will work in these situations, because that's simply not true. Here are two UOAs of very comparable trucks in very similar situations of use; one is my UOA and one is from a guy in Alberta, Canada. I use dino 10w-30 HDEO and he used RL 15w-40 (a premium syn) AND bypass filtration. Look over the UOAs; I challenge anyone to show that there was any real statistical differnce in wear protection ... http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2323660&page=1 http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=2379331&page=1 Bottom line is that you can choose either of the two fluids you have access to with confidence, because the low and high temps of the area your friend is in likely are not extreme enough to make any difference. You might as well choose the one that costs the least.
 
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chevrofreak

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4,942
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Billings, MT
I'm not confusing windchill for anything, and my friend does not live in Billings, he lives up in the mountains near Absarokee. At some point almost every winter the temps see -30F. By regularly, I meant nearly every winter, not every day. I've started my car when it was that cold, and it was one of the ugliest sounds I've ever heard from a vehicle. He doesn't have a garage for the truck, and can't plug it up when out on a job site.
 

dnewton3

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8,599
Location
Indianapolis, IN
The average low is +11 deg F in his town. I'm sure we'd all agree that "average low" is just that; there are days it's warmer and day's it's colder. That town he's in is only 4 deg F colder than Billings, on average. And only 7 deg F colder than where I'm at (central IN). In fact, nearly all the record lows in his town are only in the -30s. I understand what your saying, but I don't agree that its so darn cold that synthetics are a must. UOAs show that a large difference in base stock does not manifest itself into a large difference in wear protection given the temps he's seeing. I point this out because your first post in this thread was asking about the CCS and MRV of the two products and how they contrasted in cold temps. Your quest, in essence, was a "which is better" topic. The two oils will react a bit differently, but the wear protection they provide is (statistically) going be be the same. If my dino oil can protect against wear as well as a premium syn, then the comparison of two syns are going to be very much the same. I see this type debate so very often here; people get all frenzied over the oil and debate nuiances that simply do not matter in the long run. Which is more important; knowing the line-up roster of a ball team, or knowing the final score of the game? Same goes with oils. Don't get so caught up in which oil has what additive or base stock. Look at the wear as predicted by thousands of UOAs. Knowledge of MRV is an input; wear data is an output. Let's suppose for a moment that there was a wear difference of 10% between the two oils you mention. (I do not for one second believe this to be true, but I'm making a point here). If the "inferior" oil come with 10% more wear, then wouldn't that mean 10% less final lifecycle? If his engine is good for 400,000 miles, then it would be "only" good for 360,000 miles with the lesser oil. Is your buddy ever going to drive that far? Only people who drive lots of hours every day ever rack up that kind of mileage. And if that were true of your friend, then "cold starts" are not a major concern for him because he's going to be at full temp for the vast majority of the operating time. Or, the opposite is true; he may only put 200,000 miles on that truck, if even that, and it would take him 15 years or more to ever get to half of the lifecycle of the engine. In that case, why even worry about it; there is a HUGE potential for the vehicle to be stolen, wrecked, or just plain traded in before the engine would give out from the "lesser" oil. Simply put, it is silly to worry about wear unless there is a reasonable expectation that one would actually reach the finite end of the lifecycle. If that is not a reality, then the topic of wear is moot. If wear is not an issue, then one can at least debate the "ease" of starting. You say you don't know which engine he has, but we can at least know that the 7.3L, 6.0L use HEUI. That in mind, a thinner oil is going to aid in quicker revolutions for starting compression, and will quell (or at least reduce) the dreaded "romp" of HEUI in PSD engines. I know of a few guys that run 10w-30 and one that runs 5w-30 in their PSDs. We all agree that there is little difference between the two choices when it comes to cold starts, but we also agree that the 5w and 10w do outperform the 15w products on cold starts. In essence, the HEUI systems seem to prefer thinner oils. Here's what I see as a factual basis for this discussion: * It's cold where he's at, but not stupid-uber-ugly cold like what is seen in the upper northern part of this continent * At the temps in his area, any 5w or 10w oil is going to do just fine, and countless UOAs prove that * The two oils you mentioned are very likely going to give the same wear protection, regardless of the difference in MRV values * You can get your friend a great deal on some nice PAO oil * He should buy whatever oil he darn well wants to; that's the only way he'll sleep well at night
 
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1,456
Location
Alaska
We all know about statistics, particularly those of us with science backgrounds. What is the average low for Absarokee in Jan? What is the average record low for the month of Jan in Absarokee? Where I live the average low in Jan is +9F but the average record low for Jan is about -25F, approx. And we have a transitional climate with an ocean nearby. Average worst low is important if you have to start your car outdoors every day. I would not want to start my vehicle(s) with 10W30 at -25F even once. Please let us have some relevant statistics - all of you threaders, please. Charlie
 
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1,456
Location
Alaska
i find for Absarokee Mt for January: average min 10.3F. extreme min -26F. Too cold IMHO for a 10Wxx Sounds like a 5W40 or 0W40 would be appropriate for outdoor starts. Charlie
 
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3,371
Location
Idaho
Originally Posted By: Garak
I don't approve of battery blankets. Heat is a big enemy of batteries and people generally leave the things on all year, rather than take them off in the spring. ..............
Another problem with a heated battery is that in combination with a cold voltage regulator/alternator, it leads to overcharging of the battery. The temperature sensor in the voltage regulator assumes that the battery is the same temp as the alternator/regulator, and will bump up the charge voltage on a cold day.
 

dnewton3

Staff member
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8,599
Location
Indianapolis, IN
According to the government NOAA and NCDC data sites, the average low temps in December/January over the last several years in that area is approximately +11 deg F. That is for Columbus, MT, which is very near Absarokee, MT, so it is a good representation of the weather in that area. Columbus, MT is the only "official" weather station for that area but it's darn close enough with only 400 feet difference in elevation and being about 10 miles to the north of Absarokee. That being said, the statistical data shows the standard deviation to be about 7 deg F for that time of year in regard to low temps, so even the traditional "3 sigma" limit would be around -10 deg F. (Figured as +11 deg F - (3*7) = -10 deg F). In other words, 99% of the time, it will be no colder than -10 deg F. Yes, that's cold. Yes, it will get below that. But the vast majority of the time, the low temps around Absarokee will be -10 deg F or above. It’s not near as cold as we’re lead to believe; the OP's statement was Montana winters “regularly get down to -30F or lower”. I disagree when speaking of that area. It may see an occasional record at or below that temp, but the routine low temps for Absarokee, MT are much closer to -10 deg F and above. (And frankly, that is within the reasonable range of temps for a 10w-30 HDEO.) And again, we don’t know which engine we’re talking about here, so it may or may not have an intake-grid-heater. Strong batteries and thin oil are going to assist this person in cold starts and protection. As Chevrofreak mentioned, his friend does not have routine access to a garage or electricity, so a pan heater or battery blanket are not an option on a regular basis. Further, with today’s weather-prediction equipment, uber-cold fronts are not a surprise by any means. If he expects -30 deg F or lower, then he can make arrangements to idle the vehicle, or take starting aids along with him in the truck. I fully agree that the friend of the OP should use one of the 5w-40 fluids that can be had for cheap as it makes good fiscal sense; I wish I had access to such deals. Either fluid is going to be more than capable of handing the temps that will be experienced for the bulk of the time. The OP’s original question was essentially “it’s so darn cold; which oil is better”. My answer is that it does not get cold enough in that area to warrant a concern over the small performance difference, as the ultimate goal is to protect from wear and ease compression-ignition starting. Given the temps that area sees 99% of the time, either oil is going to do just fine and you’d likely never see any wear difference in statistical UOA evidence contrasting the two.
 
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