Fiat’s new 500 uses the oil to hydraulically actuate the intake and exhaust valves (the “Multiair” system):
I Googled it and found several articles that said this oil improves gas mileage very little but increase engine wear and that car manufactures recommend this oil to help their CAFE numbers and to get you into the show room for a new car sooner. is this accurate?
No, that is not right.
Well, the part that is in bold, anyway.
20 weight oil doesn’t cause any more wear than 30 weight oil does, under normal driving conditions, for an engine that was designed for it. This Subaru engine you are talking about, was designed for this oil to be used.
Yes, 0W-20 oil does give better fuel economy than a 5W30, 10W-40, or a 20W-50 oil does.
Way better gas mileage than the 50 weight, quite a bit more than the 40 weight, and a bit better than the 30 weight.
It also improves the CAFE mileage for the company in comparison to what they would get if they used 20W-50 oil all across their vehicle lineup.
But in regards to wear, that’s not true, by any stretch.
In fact, if you look up the PDS from just about any oil company you can pull up, just about every 0W-20 and 5W-20 oil will have a higher flash point listed than the identical oil in 5W-30. Boggles the mind that a thinner oil can endure higher heat than the next oil up the ladder, doesn’t it?
Here’s proof of that too:
http://www.mobil.com/USA-English-LCW/carengineoils_products_mobil-super.aspx#
Click on the tab for Tech Details, and look at the Flash Point for Mobil Super 5000.
The flash point is higher for the 5W-20 than it is for the 5W-30, and the 10W-40.
I wouldn’t use this weight oil in a work truck, while towing a 15k lbs trailer up a mountain pass in the middle of summer, but for a normal small car engine, its perfectly fine for daily driving abuse. Its also way better for the engine in extremely cold climates.
BC.
Honda uses it too I’ve been told.
I’d like to add a thought to the “planned obsolescense” theory. With so many competitors’ vehicles lasting 300,000 miles and more today, a manufacturer would be suicidal to design premature wear into their engines for the purpose of getting you back into the showroom sooner…because you’d head for somone ELSES showroom.
I truely believe that manufacturers’ design groups make every effort to creat reliable, long-lasting cars as best they can while still keeping them affordable for the target markets. Unfortunately, countless compromises are made in the corporate offices in the interest of “corporate identity” and overall corporate profitability that adversely impact longevity and reliability. The goal isn’t planned lifespan, just maximum profitability.
As to thinner oils, in the interest of meeting emissions and CAFE mandates and the reaultant smaller engines, combined with new technologies in use creating lighter parts and more consistant parts, there may not be as much load placed on the critical areas of crank bearings and even cylinder walls as there used to be. Crankshafts deflect in use, and perhaps today’s little engines simply don’t place as much load on the bearings.
Bladecutter’s comments about towing made me think about this. An engine pulling a 15K trailer up a mountain pass places far more load on it’s piston rings (which load tranfers to the cylinder walls) and crank beariings than driving a little Toyota or Honda with a little high-revving 1.8L motor. That means the little Toyota or Honda may not need as viscous an oil. Its critical parts aren’t under as much load.
It’s just a theory. I have nothing to back it up. But I know that higher pressure applications, like differential gears whereing the gear teeth lube has to withstand greater pressures, need to be thicker to do so. 75W is better able to withstand conpression forces than 20W.
Comments, anyone?
If you want to preserve your new car power train engine warranty use the 0w-20.
I would not lose sleep over wear. The engine will last the life of the car if taken care of properly. Basically timely oil changes.
The engine will last the life of the car if taken care of properly.
Am I the only one to think that sounds a little funny? Usually, the life of the engine determines the life of the car. If your transmission goes out, but the engine is still in pretty good shape, you would probably be inclined to fix the transmission. It’s a little like telling a guy with congestive heart failure that his heart will last the rest of his life.
This isn’t the old days. In the good old days, we used 10 weight in the winter, and 30 weight in the summer. We used Champion J-8 spark plugs. If the valves were in the block where the good lord intended valves to be placed, we used non-detergent oil. Engines usually had a ring and valve job at or before 80,000 miles.
I think that the engineers who designed your Subaru engine knew what to recommend for oil. Anyone can post an article on the internet, but that doesn’t make the contents of the article factual.
A friend I knew had a 1955 Oldsmobile V-8…To everybody’s amazement he used only 20-20W motor oil the year round. EVERYONE knew you HAD TO USE 30 weight in the summer…That Oldsmobile finally rusted away, it’s engine still purring…So I guess engines can survive on 20 weight oil even in summertime temperatures, regardless of the “tolerances” they were built to…
Comments…
My Chrysler Hemi engine calls for 5W-20 oil. This is pretty much the opposite of a tiny, high-revving 4-banger. It’s more of a torque monster that makes most of its power at lower RPMs. While it does have more cylinders so the load is distributed more than a 4-cylinder, it certainly puts a lot of force on the bearings. The SRT-8 version of this engine has higher horsepower, no cylinder deactivation, and ‘piston squirters’ that spray oil at the underside of the pistons for cooling purposes. These engines are spec’d for a heavier weight oil—5W-30 I think.
I suppose if the parts are rigid and the clearances are tight, there’s no place for the oil to go under load, so the film is maintained on bearing surfaces. You’d think it would beat up the oil more, but there’s no real evidence that this is happening.
If the good lord intended valves to be in the block, then the good lord just doesn’t appreciate horsepower 
Older cars are having problems because of the lack of zinc additives necessary to protect the sliding surfaces of cam lobes and rocker arm tips,especially with high pressure valve springs. Modern engines use roller rocker arms which eliminate the sliding motion.
Up here in NH rot, change in lifestyle/needs, and/or chassis wear has always determined the life of my vehicles. I’ve yet to wear out an engine. Note that I’m including systems like brake lines etc. becoming too deteriorated from years of road salt to be considered safe under the heading of “rot”.
The good lord made you with your heart valves in the torso of your body near your heart. The good lord didn’t place your heart valves in your head with a timing belt running up your spine.
In that scenario, I would be tempted to keep the engine for a project, like a street legal dune buggy or three-wheeled motorcycle. Maybe I would try to get my hands on an Ariel Atom without an engine, and after overhauling my Civic engine, install it in the Atom’s chassis. If it was a larger engine, like a V6 or a V8, I might look for an old jeep chassis in which to install the engine.
In the 1970s, my parents bought used station wagons, and they always got hauled off when the engines quit. In fact, in my entire life, neither me nor my parents ever let go of a car with a properly working engine, even when we lived in Buffalo.
Why in the world would anyone still want the valves in the block? There is no way we would be able to make engines with power and efficiency even close to what we have today with the valves down there. Just like the valves in the heart being where the holes they open and close are. The intake and exhaust ports are in the heads, not in the block.
There was one that I wanted to keep, my ol’ pickup. It was over 17 years old and over 300,000 miles. I wanted to use the chassis and drivetrain to put an old body on, perhaps a Vicky or a late '20s pickup, and make a rat rod. But. alas, I gave it to my daughter instead.
I gave my son my '91 Camry at the same time for a Boston beater.
The others I all traded.
Comment: I am always way more skeptical than most that “market” mechanisms having to do with keeping consumers happy assure us that we always get the best stuff & recommendations that are possible. This kind of logic overestimates how good everyone’s information is, assumes that the power over situations involving product problems are equal between manufacturers and consumers, and overestimates the actual “rational” component of consumer activity. It works in textbooks, but much less so in everyday practical activity.
It also doesn’t explain why manufacturers, for instance, give what is blatantly terrible advice for things like transmission maintenance. Or put out things like DexCool.
That’s just a general thing about the logic - it doesn’t mean I’m saying 0w-20 is a planned obsolescence thing. I simply don’t know enough of the details of engine design & lubrication stuff to have any serious judgment on the issue. What I do know is that I don’t just trust those who manufacture things on the assumption that their best interest is watch out for my best interests. Its just so obvious that that is often a bad assumption.
I appreciate you guys’ comments.
Oblivion, you may be right that the posit that smaller engines exhibit lighter loads simply doesn’t fit the actual information.
Whitey, I’ve never quite “bought into” the planned obsolescence theory. But it is possible that design teams make assumption about vehicle lifespans and use those to base their recommendations on. If one assumes, for example, that the avarage buyer of a new car will trade it after 100,000 miles than perhaps the bad advice of never servicing the tranny seems prudent.
And my theory certainly doesn’t explain why some manufacturers have a specific problem for decades on end and never seem to eliminate it.
Valves in block --> horse sense --> easier to repair
Valves in head --> horse power --> harder to repair
Horse power vs. horse sense Take your choice.
Back in the early 1950s, Hudson won big time in the stock car races and the Hudson engine was a flathead 6.
In fact, your friend may have been better off using 20-20W in the 1955 Oldsmobile due to the fact that the oil would circulate faster at start-up and cause less wear. In the winter, the 20-20W would give better protection than 10W once the engine warmed up.