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I wouldn't if the engine has seen nothing but an Xw-30 oil. Here's the why. As an engine wears in, it wears according to the viscosity oil that is in it. As the lower bearings wear in, they wear in a slightly elliptical shape. This is so that the oil when under pressure, forms a wedge of oil and that's how the bearings are lubricated. The bearings wear to the viscosity or film thickness of the oil. Use a lighter viscosity oil and the oil has a tendency to run out of the bearings before it has a chance to spray the ring packs and the bottom of the pistons, assuming you know that the bearing caps provide the spray for rings/pistons. You can actually have a good engine running in an oil starvation condition by using the wrong viscosity. Remember, the engine was designed around the lubrication system, not the lube system designed around the engine design. Engine designs start with ILSAC and then on to API before any clean sheet paperwork on an engine design starts.
And before somebody jumps on this band wagon, yes the engine is backwards compatible with the Xw-20 oils. Just with over 50,000 miles on the clock is not in the best interest of engine life.
I would use what's recommended by the automobile manufacturer, and after looking at the chart for oil viscosities and temperature. For example, I would use 10W-30 in Florida, simply because 5W-30 is not recommended by oil manufactures if ambient temperatures reach 60 degrees. But 10W-30 is well within the temperature range, from slightly below 0 to past 100 degrees.
You could probably do ok if it is synthetic....regular oil, I would not do it.
I was reading about 0W-20 at Mobil Oils, and according to the data at their website this oil should handle the temperatures of Florida, except if towing with the car. But I would not use it since 5W-30 would be better suited for summer driving.
You could probably do ok if it is synthetic....regular oil, I would not do it.
Unfortunately, a common misconception these days. There was a time when motor oils using a GTL base oil (GTL= gas to liquid technology) were more thermally stable but those days are gone as well as the GTL base oils of yesterday. The ethylene gas used to make them has gotten scarce. There are very few "real" synthetics on the market these days as most are a Gp III severely hydrocracked crude..... and that's the good ones. Today the blenders have pushed the envelope and what you bought 5 years ago as a "regular" oil is now a synthetic. Some are going so far as to include a Gp II base as it does not appear in nature. But the oils that are out there are some of the best you've ever bought even versus yesterdays synthetics. If it wears any Ford spec on the bottle, the oil is double length time tested at 302F (16 hours) and deposits are far less than API requirements. It's a far more stable oil than anything you've ever bought.
IN regards to the use of the winter weights like 5w or 10w. The info given at the link is old, real old, and is not relevant anymore. Back in the 90's the blenders would use a polymer to make the viscosity spread. Today it's done by using a base oil of the correct viscosity index. Polymers are only used to trim the specs. FWIW, tribologist world wide have stated that any winter weight oil of less than a 5w is not necessary or needed. If you have extreme cold starts, look at the CCS or Cold Crank Simulator specs of the oil- less is better. Comparing some of the 10w to the 5w oils and you might be surprised that some of the 10w actually have better cold crank characteristics. Otherwise, it makes no difference to use a 0w, 5w, or a 10w during the summer. None of it is at it's lowest flow point and all of it will thin out to the top number.
Always use a quality, name brand motor oil in the viscosity recommended by the maker. Change it at the recommended intervals, sit back and enjoy the ride. You trusted the maker enough to buy his product, trust him enough to know that it wears his name and he knows what is best for it.
Please note that it makes no difference what oil you are using. The 0W-20 Mobil 1 that is SL rated meets the same criteria as that SL rated 10W-30 synthetic or mineral .
but 10w-30 is recommended.
A 20 grade oil at operating temperature. We get the same flow out of our constant volume pump but the thinner oil requires less pressure to move through the system
I have some stories that I collected. First, my architect drives a big SUV. He was running with Mobil 1 brand 15W-50. He changed it to Pennzoil Multi-grade (mineral oil based, non-synthetic, cheap) 5W-20 at my suggestion. His gas mileage went from 10 to 13 MPG around town. What really impressed him the most was the “robust” increase in “get up and go.” He changed from a thick synthetic to a thin mineral oil. His venue is stop and go city traffic in Florida, mostly short trips. The oil just never got that hot to require a 50 grade oil. Short trips means that the oil temperature never gets up to the normal operating range. It was too thick on short trips and too thick when it did get up to temperature.
All manufacturers I have seen are specifying 0W-XX or 5W-XX oils now. Honda, Ferrari, Ford, Mercedes, Porsche, and others specify a 0 or 5W-XX oil to mention a few. These are appropriate for all engines of all ages of all levels of wear. This second number is the only thing that may change with an older, lose or worn engine. This can only be determined by experimentation. If you are using XW-50, go to a 0W-40. If your pressures are still too high go to a 0W-30 and so on.
Always use the most currently available, highest rated motor oil, even in the oldest, most worn engine.
More confusion occurs because people think in terms of the oil thinning when it gets hot. They think this thinning with heat is the problem with motor oil. It would be more correct to think that oil thickens when it cools to room temperature and THIS is the problem. In fact this is the problem. It is said that 90 percent of engine wear occurs at startup. If we are interested in engine longevity
a 0W-30 grade oil is not thinner than a 10W-30 oil. They both have the same thickness at operating temperature. The 0W-30 simply does not get as thick on cooling as the 10W-30. Both are still way to thick to lubricate an engine at startup.
Note that a straight 10 grade oil is also too thick for your engine at startup. It has a thickness of 30. Yet at operating temperatures it is too thin having a thickness of 6.
engines of any age, loose or tight. Just because your engine is old does not mean it needs a thicker oil. It will need a thicker oil only if it is overly worn.
Older engines may in fact benefit from thinner oil use. Over time permanent deposits of carbon and sludge build up in the engine oil ways. It is like a clogging of arteries in humans. We are now all on blood thinners
The best way to figure out what viscosity of oil you need is to drive the car in the conditions you will use. Then use the oil viscosity that gives you 10 PSI per 1,000 RPM under those circumstances.
Remember, the only difference between a 0W-40 and a 10W-40 is that the 0W-40 thickens less after you turn off your engine. It is still too thick in the morning at startup but not as thick as the 10W-40. Yet, they are still too thick to use until they both warm up to operating temperature at which point they have the save viscosity, around 13 to 14. Remember that the 0W-30, 10W-30 and straight 30 grade oils all have a viscosity of around 10 at normal engine operating temperatures. They all thicken when you turn off your engine. The 10W-30 will thicken the most.
There is one more thing. A 20 grade oil is not half as thick as a 40 grade oil. The real scale is more like the oils having an absolute thickness of 108 and 114. Now it can be seen that the 40 grade oil is only around 10 percent thicker than the 20 grade oil. The difference is not that much at operation but at startup the difference is significant. Pressure / flow dynamics go along with this 10 percent figure. A 30 grade oil should be thought of as having an absolute viscosity of 110 and a 50 grade oil has an absolute viscosity of 120. I am talking about the viscosity at operating temperatures.Motor Oil 108 - Bob is the Oil Guy
I would like to comment on the following statements made by a knowledgeable automotive enthusiast:
“Pressure and flow are tied together with viscosity, but none have anything to do with lubrication. Lubrication is a property of the fluid, not the force. The oil pump would pump water just as well, but it would offer no real lubrication. If we double the pressure, we double the flow. If you decrease the viscosity to a lighter oil, you increase flow at a loss of pressure. High flow helps to carry away more heat. High pressure helps to keep metal parts like the bearings out of contact with each other (scuffing).”
I was reading about 0W-20 at Mobil Oils, and according to the data at their website this oil should handle the temperatures of Florida, except if towing with the car. But I would not use it since 5W-30 would be better suited for summer driving.
Yup, best have a real tight engine if you are putting 0W-20 in it. Any minor little leak is going to pass that stuff. Probably burn it in the combustion chamber too if your oil rings are a little tired.
But on the plus side, if you have a light duty vehicle, add the 0W-20 synthetic and you can get a little better gas mileage.
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