I have a 2011 Toyota Sienna that I purchased in March of 2010. The manual calls for 0W-20 synthetic oil. I have driven it on 350 mile trips on the interstate when the outside temperature was 95-100 degrees. I have started it in sub zero weather. I have 24,000 miles on the Sienna and it has never used any oil between changes.
I’ll report back when I have reached 100,000 miles.
As has already been stated and repeated here, use what the manufacturer recommends. None of us here was a part of the design or reliability testing teams, and they’re the ones that developed the requirements that were put into the owner’s manual.
Realize that
- the “0” is simply a reference on a scale, just as “0 degrees C” is just a point on a continuous scale. It’s a way of measuring, not a value rating.
- oil in today’s engines is used for more than just lubrication. It’s also used almost as a hydraulic fluid to control the variable valve systems.
- Today’s engines are manufactured to far more consistant dimensions that was possible in the past, and thet allows tighter tolerances. So they are designed that way.
Old habits do sie hard. Old perceptions die even harder. But you can trust the design team’s requirements. An enormous amount of analysis and testing was done befor they were put to print.
The mileage requirement is paramount…They will use the thinnest oil possible that still delivers acceptable engine life…With todays chemistry and the consumers willingness to spend $5 and up for a quart of oil, lubricants can be developed that can keep engines alive with very low viscosity numbers. “Thin As Water” motor oil can’t be far off…
I agree with Caddyman and I have to respectfully disagree that this has anything to do with the alleged tighter oil clearances on modern engines theory.
Check any service manual for crankshaft bearing oil clearances, cam journal oil clearances, and so on.
One would find that the oil clearances on a 2006 model car are all about the same as a 1996 model, a 1986 model, a 1976 model, a 1966 model, and so on down the line.
Engine clearances probably haven’t changed, but modern fuel injection has helped keep the oil from being diluted with gasoline as happened with the old carbureted engines. In cold weather, the choke would enrichen the fuel/air mixture with excessive gasoline. I used to change oil every 2000 miles in the cars I owned in the early 1960s, and I only used straight weight oil: 10W in the winter, 20W-20 in the spring and fall, and 30 in the summer. When I purchased an almost new 1965 Rambler in 1965, the manual called for 10W-30 year round. I did go along with this recommendation, but I didn’t go along with the 4000 mile interval for oil and filter changes. I did the oil change every 2000 miles. With the later vehicles I have had, I go along with the owner’s manual on oil viscosity and have had no problems.
I agree with you about modern cleaner burning engines leading to cleaner oil. The absence of lead in gasoline has made a big difference too.
I think one area where GREAT improvement has been made is piston design and piston ring sealing…Todays engines have far less blow-by…Back in the day, factory piston and ring fit was somewhat hit or miss, the machining in this area somewhat less than perfect…
Point made, OK4450.
While I agree that tolerances for rebuild haven’t changed, the tolerances acceptable to the manufacturing processes have changed dramatically. Dimensions considered acceptable 30 and 40 years ago have a far greater range, were allowed to vary from the nominal far more, than would be allowed in today’s manufacturing environment. Oil specifications are selected based upon how engines will be out of the production ilne rather than engines to rebuild tolerances. Clearances for the surfaces you mentioned in the engines leaving the factory are tighter and more consistant than those you’d use for rebuild. It’s using those manufacturing dimensions that accelerated life testing, reliability testing, etc. are performed and evaluated.
For our newer readers, this is a subject OK4450 and I have discussed before on the site. I think our different conclusions aome from differing backgrounds. Ok4450 has loosed more bolts than a midwest electrical storm, whereas I’m steeped in the manufacturing industry. Our perspectives on the origins and applications of the thinner oils being recommended and the tolerance aspect of it therefore differ somewhat. But the bottom line is that the owners’ manual is the bible for what oil to use. The subject we’re disagreeing on is purely technical. I have all the respect in the world for OK4450, and have learned a great deal from him, but will continue to believe that tighter manufacturng is an aspect of the recommendation of thinner oils.
The problem I have with the idea that the oil specification is strictly a manufacturing/build issue…is that on some engines the oil recommendation has changed over the years…but the engine hasn’t. The engine’s are being built the exact same way with the same machine processing they were using just 2-3 years earlier…but the manufacturer changed the oil viscosity recommendation.
#1 Either they made a mistake 2-3 years ago.
#2 They’re making a mistake now.
#3 There’s some other reason for the change (i.e. Cafe’ numbers).
I would add this. There’s a perception that machinists back 50, 75, or a 100 years ago were hacks churning out metal on an antiquated lathe and using a ruler for a measuring device. Those guys were much, much more precise than they’re given credit for and especially considering there was no CNC machinery back then.
I do agree that modern computer controlled machines may statistically keep all of those parts closer to one another as to their final machined size but any variance between the old and new process is so minute as to be irrelevant.
If one checks the service manuals one usually finds crankshaft oil clearances at about .001 to .003 inches.
If one tore down new engines which have not been run and checked the actual clearances one would find a variation in journals but that variation would not be enough to mean anything over the long run. In other words, an engine sitting at .002 exactly on all journals is not going to last one minute longer than an engine with specs ranging from .0018 to .0023 and so on.
Regarding the old timers and their machining, consider Harley Davidson motorcycles from back in the 20s and 30s. Like today, their crank bearings are more precise than your average automobile.
Crank bearings are offered in oversizes of .0002 of an inch with 5 increments leading up to .001. Once wear exceeds a thousandth of an inch it’s time for new shafts and races.
It’s impossible for the average person, without very expensive micrometers, to separate rod bearings like this and the factory recommendation is that if rod or main bearings are not in their sealed bags they should be throw in the trash due to the strong possibility of size mixing.
I respectfully disagree.
That perception is erroneous and was never shared by myself or anyone I’ve ever worked with. I and all my colleagues have only the utmost respect for machimists, and having worrked with them for many, many years I’m fully aware of the level of expertise, knowledge, and experience involved. Let it never be said otherwise. There’s far, far more to machining than just cutting chips.
Re: CNC machinery, (now driven by CADD/CAM software), there’re machine operators, machinists, and (still) toolmakers. The most skilled being the latter. And long before tapes there were people making precision parts. The insutrial revolution, indeed the railroads, would not have otherwise been possible.
However, Statistical Process Control has enabled diimensions to be maintained to variances 10X and better of what they could be maintained to prior to SPC. Where a drawing tolerance might still be +/-.002, the Lower and Upper Control Limits can now be maintained to within +/-.0002…often much less. Where it was .0002, it can now be maintained to another whole decimal. And it’s far less expensive to operate a production line using SPC methodologies than operating to the drawing tolerances. There’s far less waste and far fewer problems. Variations other than statistically normal are corrected before tyhey manifest themselves as unusable parts, parts interfaces are more precise and reliable, and even the waste attributable to setup can be reduced. Even preventative maintenance costs can be better controlled.
The factories are long past using precision micrometers for critical measurements. Programmable laser Coordinate Measuring Machines in environmentally controlled rooms are the norm now.
I recognize that not all car parts get this level of precision, but the engine’s internal critical dimensions do. I’ve seen them produced. And as you may have guessed, I’m well versed in the methodologies.
I have only respect for the machinists of old (and new), and I marvel at their skills and what they accomplished. But the truth is that manufacturing capabilities have dramatically changed these past decades. Technology commonly used today wasn’t available to machinists of old. Much of the technology commonly used in producing engines today stiill isn;t available to most shops.
Just as marveling at the space shuttle astronauts in no way takes away from what Alan Shepard did, accepting the realities of modern manufacturing capabilities in no way takes away from what machinists of old achieved. Or, for that matter, what a good modern small shop can accomplish.
I agree with you about the accuracy but my point is that it doesn’t matter on a production vehicle.
Still using the crank journals as an example, the fact that the number 7 rod journal may be .0002 smaller or larger than the number 4 journal is not going to affect the engine’s longevity.
If things were that precise there would be no need to publish a crankshaft endplay spec of .006 - 013 for example. Every car would roll off the line at a dead-on .0095.
This is especially true with transmissions and I’ll use my favorite, Subaru, as an example because they’re the worst offender IMO. Their manual transmissions are chock full of selective washers, spacers, shift forks, bearing shims, and whatnot. The purpose of every single one of those items is to account for production variations during the original assembly and when/if the transmission has to be taken apart for repair or overhaul.
Would it be your position that 2 engines (all things being equal as to use and maintenance) would lead to the engine with dead-on specs all the way through leading a longer life span than one that had minor variations?
Actually, that would be my position. I believe that’s part of the reason that engines today last so much longer without internal repair than the engines we grew up with. I believe it contributes to less stress of the parts caused by imbalances, less blowby, more consistant cylinder, bearing, and journal wear, and perhaps even less internal friction.
Shimmed assemblies excepted, tolerances of “play” between parts may still be comparable, but the actual measurements are far more consistant. The tolerances may be acceptable, but they’re not representative of what teh factory is turning out.
I also believe that other factors such as improved materials, dramatically improved design computer systems (who’d have thouoght that one could “model” temperature variations or do instant finite element analysis the way we can?) improved materials and material processes, better oils, etc. have also contributed to longer life engines. But I don’t discount the value of the more consistant and predicatable critical dimensions.
I had the same question – “how can something so thin be any good” – and finally a Ford manual specified that the thinner motor oil can better lubricate parts with smaller, more precise clearances.
So … thinner flows better.
In the old days, oil needed higher viscosity (hence higher numbers) because viscosity kept oil from breaking down at operating temperatures, but newer oil technology doesn’t break down as much. Newer thin oil also has better additives, according to Ford. Well, they know best. When all else fails, use what the manual recommends.
I wonder how many people back in the '30’s fried their engines because they insisted that straight 40 weight was the best oil, and all them new-fangled variable viscosity oils couldn’t be trusted.
I disagree that old engines (50s, 60s, etc were prone to short lives because of machining that was not precise.
Many were killed by the same thing as now; lack of oil changes and overheating. The obstacle that engines way back when had to fight was leaded gasoline. Much of those deposits ended up in the engine oil.
If sloppy machine work was the cause then one would not see all of these old cars with high 6 digit mileage on untouched motors. For example, a recent issue of Mopar Muscle had a story on a guy who bought a 65 Polara from the original owner. He drove this car for some years and many miles as is before customizing it and that was at something like 225,000 miles.
I’ve personally owned old cars with 150k miles on them and they were still running fine when I sold or traded them and a guy across the border in KS has a 68 Dodge that he bought new and has an honest 500k miles on it.
A local farmer who passed away about 2 years ago left behind a 65 Bel Air and late 50s GMC pickup that he bought new and they are still running fine to this day with untouched engines and countless miles on them. I’ve even done some work for him on the GMC.
Regarding the tighter clearance scenario, here’s one example. (Info pulled from my manuals and I’m using connecting rod oil clearance on a small block Ford as one of many countless examples.)
Modern fuel injected 302 - .0008 - .0026
1985 TBI 302 - .0008 - .0026
1965 302 - .0008 - .0015
How is the modern 302 tighter than its ancestors? The spec in '65 is actually tighter than late models.
A machinist makes small qtys very accurately. Let’s not confuse high volume production with piece work. And high volume is also relative. Lastly, materials being used today are significantly different (even as alloys of base metals. ) I agree 100% with TSM. My dad was a machinist and tool and die man for 50 years…
CAD (Computer Aided Design) of engines didn’t come around until the 80’s. And really not until the mid-80’s was the technology good enough and fast enough to help in the design of car engines.
Car engines designed and built in the 70’s were VERY reliable. I’ve seen Chrysler Slant-6’s with well over 400k miles on them…GM Small-block V8’s could easily go 300k miles if properly cared for (and not abused). And I’m quite sure those engines weren’t built with the same tight tolerances they are today.
Now I will agree that there might have been a higher number of these engines that were junk with less then 100k miles on them even though they were cared for.
OK4450, I think you’re misunderstanding me. Machining was not imprecise. In a mass manufacturing environment it was performed extremely accurately to within the design tolerances. But in today’s world, in the mass manufacturing environment, machining in any modern shop is performed to within the limits of natural variation. The tolerance might be +/-.005, but the process is controlled to produce parts to +/-.0005 (or whatever the +/- three sigma establishes after all anomolies to the curve have been eliminated and the variability reduced).
Every engine has hundreds of critical dimensions. Over 100,000 engines, the differences in those approaches make a huge difference in aggregate longevity of the engines.
Understand that in no way should my commenst on the evolution of mass manufacturing accuracy be interpreted as a criticism of machinist and/or toolmakers…regardless of the era in which they work(ed). I have only the utmost respect for and awe of machinists and toolmakers of all eras. But W. Edward Deming really was right, far better accuracy can be obtained by focusing on the process variations than on the dimensionsl tolerances.
Allow me to use a shooting target as an analogy. It’s like the difference between a rifle being handheld by a marksman being able to get all the rounds in the bullseye, and a rifle being held by fixturing being able to get all the rounds to where the holes are ajoining one another in the center of the bullseye. The latter doesn’t take away from the skill of the marksman, but it does improve the results.
I completely understand your reasoning and point taken even if I do not agree with it and as I said, I do believe modern machinery is not only faster but much more accurate.
Let me pose this question and it’s in regards to the Subaru manual transmission. Take half a dozen brand new units (never installed) and tear them down on the bench.
Swap all of the mainshaft assemblies from one transmission to another. With modern precise machining this means that the placement of say the 3/4 shift fork should hold the 3/4 synchronizer sleeve in the same spot and there should be no need to alter anything. Correct?
While I;m unfamiliar with that specific assembly, that theory is correct, assuming that any shim or adjustment protocols are properly followed. It’s the principle on which mass manufacturing was built…interchangable parts. It made Henry Ford rich and the rest of us mobile. Without this truth, we woudn;t be having this discussion. We’d be discussing the latest in horseshoe technology.