4.6 Motor Question

You must be an old timer like me, used to using 20w-50 in everything ;-

The engine will get hot, yes. All newer engines have closer tolerences that benefit from the lighter oils, and the result is lower emissions and better gas mileage, so says the Gov't.

Check the manual for the temp range for the oil weight. It may recommend a slightly heavier oil for very hot summer running but probably not any higher that 5w-30.

If you're worried about the oil breaking down, use synthetic. I wouldn't advise using a much higher weight, though.

rd

Use 5W-20 or 5W-30 synthetic and don't worry about it. It's a water cooled engine, it will get hot no matter which oil you are using. Regular preventative maintenance(cooling system included) is the key. Use Ford spec WSS-M2C153-F oil or better & you'll be fine.

Rob

I dunno, at work 10w30 goes in all the new ford motors, the 3.0L rangers and the 4.6L f150s alike, and the 5.4s as well

You can run 10W40 oil in the 4.6 as long as you change it at leat every 5000 miles - 3500 is better (due to the viscosity shear in high VI conventional oils). You will loose a small amount of fuel efficiency - C.A.F.E. is the major driving force behind the ultra thin engine oils. The engine clearances have changed VERY LITTLE over the last 30 years. Engine finishes have improved, allowing closer absolute fits on some parts (while maintaining approxemately the same average clearances)

My Masda also requires 5w20. Dealer told me it may have something to do with oil filter not suited to handle heavy oil.

Same filter used in pre 5W20 engines. However, the small filters DO bypass most of the oil when cold, even with 5W20. Using a larger than factory supplied filter will improve cold lubrication and filtration. (assuming you can find one that fits)

When the filter goes into bypass, the oil pressure in the engine is substantially lower than the pressure shown on the guage (but a lot better than it would be if the bypass didn't open) The engine will run just fine with a totally plugged filter - but no fltering will occur and eventually damage will occur. Lots of early engines had no filters at all.

The 5w20 spec Ford uses is a synthetic blend oil which can handle the higher temps with no problem. It gives quick lubrication on cold start and, reportedly, saves a little fuel. If you do not use this, either use a full synthetic. or a good quality 5w30 or 10w30 oil. The 5w30 will result in quicker cold start oil flow than 10w30 which is desireable. If you drive longer periods where the engine is warm pretty much all the time, the 10w30 would work just as well. If the engine is never shut down and allowed to cool, a straight 30 will do as well as any. The cold starts are the bitch for the engine lube system.

Lugnut

Ford doesn't just blindly recommend 5W20 oil for all of its engines. For instance, the 4.0L SOHC V-6 sold in Explorers and Mustangs still requires 5W30. The diesel engines also require a different oil. 5W20 oil that meets the Ford specifications has to be very good quality oil. Toyota and Honda are also recommending 5W20 (and/or 0W20) oil for their newer engines. When I first got a Ford that specified 5W20 oil, I was also concerned. However after reading available SAE literature and Fords' explanation I came to believe that the 5W20 oil is a good choice (as long as it meets the appropriate Ford specs). The only time I might consider using oil with a higher viscosity is when hauling/ towning a heavy load at high speed in high temperatures for a substained period of time. I recently traded off an Expedtion with a

5.4L engine. For most of the time I owned the truck, I used the Ford 5W20 oil. When I traded off the truck, the engine ran perfectly and never needed any oil added beteween changes.

Ed

When these first came out they called for 10W30 for typical temperatures. Then the car makers wanted to get another 1% better gas mileage and developed the 5W20. The most I have ever heard them claim is that there tests with the 5W20 shows it to be adequate. Hardly a great recommendation and to get it to that point of adequacy they had to go to semi-synthetic whereas the prior oil had no trouble being "adequate" as a straight dino oil. I continue to use 10W30 in my 99

4.6

If your vehicle has an oil pressure gauge - pay attention to that for your viscosity concerns, but FIRST verify that the gauge is a REAL one, and not the disguised idiot light that Ford likes to put in vehicles. The tell is the oil sender by the oil filter: button type sender = fake gauge, can type sender = real gauge.

I run 10W40 in my Duratec 2.5

Ford hasn't used anything but the single position indicator type gauge for at least a decade (except on HD trucks). And it is not just Ford, GM has also gone to this type of gauge, as has Nissan. Unless you are going to spend the money to calibrate the sender and gauge system and educate the users, having a "real" gauge that moves around is a waste. The last variable gauge I had in a Chrysler was totally worthless. It moved around all over the place, but the readings were only loosely related to the actual engine oil pressure. It worried me greatly. I finally installed an actual direct reading pressure gauge to verify there was no actual problem.

Ed

Ford never recommended 10W30 for a 1999 4.6L engine. The oil originally recommended in 1999 was 5W30 (Ford Spec WSS-M2C153-G). A later TSB recommended the use of 5W20 oil in 1999

4.6L engines. I've never understood why anyone uses 10W30 instead of 5W30. At operating temperature there is virtually no difference in viscosity. When cold, both oils are more viscous than either oil is when it is warm, but the 5W30 is slightly less viscous and therefore a better choice for a cold engine. I've never seen any claims that 5W30 is significantly more likely to break down than 10W30 (unlike 10W40 which was alleged to suffer from significant break down problems - at least when originally introduced). The only reason I can see for using 10W30 over 5W30 is cost ($0.10 to $0.20 a quart).

In the US the commonly available 5w20 Ford Oil is a Synthetic Blend (SAE 5W-20 Premium Synthetic Blend Motor Oil - Red Bottle). In Canada the commonly available Ford 5W20 oil is a straight non-synthetic oil (SAE 5W-30 Super Premium Motor Oil - black bottle). I am not sure why there is a difference (suppliers perhaps). However, even the non-synthetic blend version is supposedly a very good oil.

Ed

There are people that believe knowing the engine?s oil pressure is vey important, and will go to some lengths to get it. See:

All of my vehicles have functional oil pressure gauges AND the idiot lights. It really makes me nervous to drive a vehicle any distance at highway speed that doesn?t have an actual oil pressure gauge. Oil pressure in an engine can decline over time due to bearing wear, oil pump, clogged sump screen, filter, etc., and if the idiot light comes on at 70 mph, it?s usually time for a new engine.

All that is fine for you, since you have may know the correct oil pressure and might actually take action if it is not correct. For the typical driver what does he learn from a full function oil pressure gauge? How many people know what the minimum acceptable idle pressure is. How about the acceptable 2000 rpm pressure is? Ford specifies that the oil pressure for a 4.6L V-8 should be 40 to 60 psi at 2000 rpm with the oil hot (and I am assuming the use of 5W20 oil). Is there any reason to think 40 psi is better than 60 psi? Ford's assumption is that if you have enough oil pressure at idle to close the switch for the indicator, that the oil pump is working and the filter is not plugged. If the pump is working and oil is flowing at idle, what could be wrong that would affect lubrication at higher rpms? Worn pump? If the pump is worn so badly that it can't make decent pressure at 2000 rpm, it probably can't make 7 psi at idle - and the light should come on. Worn bearings? If the bearing are worn so badly that the pump can't produce enough oil to keep up the pressure at 2000 rpm, then the engine is already toast.

It is important that your oil pump supplies enough volume of oil to the places where it is needed. Pressure is almost irrelevant as long as you maintain an adequate flow. You are using the oil pressure reading as a indicator that this is happening, but it is only a secondary indicator. You can have high oil pressure and still not provide proper lubrication. And you can have low pressure while providing adequate lubrication. People get into the "more is better" mode, but in the case of oil pressure this is not always true.

Consumer grade electrical oil pressure gauges are notoriously inaccurate - particularly over a long period of time. They may well have better than 5% accuracy when new, but over a period of time they drift significantly. Mechanical gauges are better at remaining accurate over time, but then you have the danger of a failed oil line. It is no fun having hot oil dribble onto your feet.

"Real" variable reading oil pressure gauges might be useful to a small number of individuals who understand the readings, who actually pay attention to the readings, and who might actually take some action based on the readings, BUT for the vast majority of car owners, the go/no go type of gauge is the proper choice. To me the go/no go type of gauge is better than the "low oil pressure" light alone, since it is a positive indicator that you have the minimum oil pressure.

Ed

What is a "go/no go type of gauge"? You mean the idiot light DISGUISED as an analog gauge? Probably LESS useful than the idiot light, except as a feel good kind of thing, since it won?t even call attention to itself as well as an idiot light if something goes wrong, and is also useless for indicating a pressure drop trend. As far as knowing oil pressure ranges on a real gauge (electric is just as "real" as a mechanical one) for a particular vehicle go, I do know, since I have the factory service manuals for all my vehicles. The electric gauges DO read a hair low compared to my Snap-On test mechanical gauge, but so what? I?d rather have them read a little too low than a little too high. I also check the electric gauges(s) readings with the mechanical test gauge every time I change the oil and filter at

10K miles; Mobil One 5W30 on all.

Your missing his point. You are among the 2% of people that actually look at, know how to interpret, and will respond to, a real oil pressure gauge. Most drivers haven't a clue. How many times have you heard inquiries that started with "My xxxxx light has been coming on for about a month..." For the majority, the go/no-go gauge or light is actually better than a gauge. A light will at least get their attention.

A go/no go gauge is exactly what it is. It is a positive indicator. If you only have the light, you only have a negative indicator. The light might not be on because the oil pressure is good, but it might also might not be on because the light circuit is bad. With the go/no go type gauge you have a positive indication that you have sufficient pressure. If the gauge doesn't come up to pressure it might be because you have no pressure, or it might be because the gauge circuit is bad, but either way you know something is wrong.

As for indicating trends - you seem to be very attentive and understand the reasons for oil pressure fluctuations. What percentage of car owners do you think that applies to?

Well you sound like a really attentive vehicle owner. Now for the big question - has all this attention to changing oil pressure made any significant difference? Have you saved an engine because you saw the oil pressure slowly decreasing over time? For me, I've never had an oil related failure of any kind. My oldest "vehicle" is a 1981 Ford

7710 Tractor. It just turned over 6000 hours (rated speed for the hour meter is 1900 rpm). It only has an oil pressure warning light. I've never really worried that it doesn't have a gauge. One of my newer tractors has a oil pressure gauge, but it isn't calibrated. It is backed up by both a light and a warning horn (plus a failure will display STOP on the main dash display). The gauge is just a bar graph thing that has no values. It is totally worthless, but it does change over time. On a hot day when you work the tractor hard, it reads lower than on a cool day when you are putting around. Over the years, it has trended lower. But so what? What should I do as a result of the entirely predictable changes? Nothing is what I've done. The gauge has been no more useful than just the warning light on the other tractor.

Ed

Oil pressure trending lower over many years usually just means normal main bearing and crank wear, but dropping in days or even hours could be a blown head gasket or failing oil pump. In one of those situations, by the time the idiot light comes on or the fake gauge SUDDENLY drops to zero, it's time for a new engine.

The same three vehicles I've had for many years:

1990 Lincoln Mark VII - 158.9K miles 1994 Lincoln Mark VIII - 109.8K miles 1990 Toyota Truck - 237.8K miles A combined total of over 1/2 million miles with 10K oil changes and ZERO internal engine problems on any of the vehicles.

I did have the idiot light on the Mark VIII turn on once at 70 mph, but the OP gauge was showing a steady 60 psi, so I just kept going. When I got the car up on ramps at home, I found it was the factory oil pressure snap switch that had failed; without the real OP gauge, I would have been really inconvenienced out there on I-35 at 2 AM, so I?ll just keep running with OP gauges in all my vehicles.

I also have voltmeter gauges on all my vehicles, since I don?t trust the other idiot light for the charging system either. :)