Gents,
I've been changing my oil on a regular basis between 3-5k miles using 5-20. My 2001 F150 Crew Cab now has 112k miles on the clock. Today when I changed it, I decided to move to a higher viscosity oil so now I'm using 10-30. My reasoning is I live in a warm climate year around. Winters here, the temp might get down to 35°F at night, but during the days, it can reach in the 70's. In the summer, temps can be as high as 100+ and even 110°F during the day.

Just wondering what some of you guys in hot climates run in your truck, especially you guys in Arizona or Nevada. Do you see any problems with running this oil since the manual recommends 5-20?

 

Here in South Mississippi I run 5-20. That's what Ford says to use so that's what I use.

 

i run 5 e 30 here in central illinois without problems. That was due to standarizing with a variety of cars and trucks, and the 5 w 20 availability was not to good a few years ago... I would think down south that 10 w 30 will not be a problem, but no real advantage over 5-30 or 5-20.

 

Why change a good thing? Ford's 5w-20 oil will suit your needs regardless of how hot it may get in your area. The 10w-30 is giving you no more protection then the 5w-20. Probably less protection as it may take longer to get to the heads on a cold start.

 

The reason they use 5-20 is the smaller oil ports, synthetic and semi synthetic oils have better high and low viscosity performance, so the 5-20 works better in both extremes... Advocates right too, you're not getting much benefit, if any, if you use 5-30... Just my 2 cents

 

ditto, i put 10-30 in my truck at 110K and it knocked like hell on cold starts. i live in tallahassee where it stays 90+ durring the summer.

 

The reason Ford calls for 5W-20 is to help improve CAFE figures, it has nothing at all to do with tighter clearances or "small oil ports". A 10W-30 takes no longer to "get to the heads" than a 5W-20, unless it is too cold to pump. A 10W-30 will negatively impact fuel economy until the oil gets close to operating temp, however.

Modulars were spec'd to run 5W-30 for 9 years before the changeover to 5W-20. Ask yourself, if these engines were spec'd for 5W-20 because of tight clearances or small oil ports, how do the Shelby GT500 and Ford GT get by with 5W-50? Their relevant (to oil viscosity) clearances are all standard Modular fare.

The 5W-20 will be fine, 5W-30 will be fine, 10W-30 will be fine, the truth is Modulars just aren't that sensitive to oil viscosity. They have enough oil pressure to be safe on 5W-20, but using a thicker oil will hurt nothing but fuel mileage, and even that is absolutely minuscule.

Another point to add, that million mile 5.4L Ford van ran Valvoline 10W-40. So much for thick oil being bad for Modulars.

 

If I recall correctly though the heads are one of the last things to get oiled on these engines. You want the oil to flow as fast as possible to get to those heads quicker. My brother in law put 10w-30 in his Explorer 4.6 and it made the thing sound like a diesel. Though we have a much colder climate then those mentioned in this thread.

I just don't see the reason to put a thicker oil in. Even if it is just for fuel economy. These are big heavy trucks and to me at least every bit of fuel economy helps. For that reason alone I would not put a 10w-30 in. At most I would put a 5w-30 if you were so stuck on the old ways thinking that a thicker oil will give you better protection.

How many trucks on here have over 200k that have used 5w-20 exclusively who live in hot climates? Seems to be alot. Sure you may not blow the motor by putting the thick stuff in, but it is not helping it at all.

I would not be able to sleep at night knowing that there was 10w-30 in my crankcase and if my truck was parked outside and the temperature was -30. We are used to using thinner oils up here. In my diesels we run a 5w-40 synthetic in winter. I've been contemplating using a 0w-20 in this truck for winter. But my GT500 does get the thick 5w-50 year round (though it is in a heated garage for 8 months of the year)

 

You see that makes little difference. the first part is its cold viscosity index. It is fairly light when cold. The second value is its hot index. The operating temperature of an engine while hot is about the same in Alaska as it is in Arizona. It tends to stay a little bit warmer than the coolant, give or take about 20 degrees. It exact temperature doesn't matter much. The kind of mileage you are running has almost no effect on the clearances, though if you reduce oil flow by running a higher viscosity, that may start to change.

The bearings through their life see almost no wear, may 1/100000th of an inch every 150,000 miles. Thats enough to mildly polish the bearings. They won't wear significantly unless they are starved of oil. The only parts that will significantly wear are rubber seals and the piston rings. The piston rings don't care so much about viscosity, just so long as oil is present.

Basically what I am saying is that Ford anticipated that you might live in a hot climate. They recommend 5w20 because it will flow the way they intended at the operating temperatures they anticipate. A heavier oil will not flow as quickly but it will make the pump work harder. While it may not break the camels back, it doesn't help anything.

 

So, at 342k miles I should have about .0000228 wear on my bearings?
I hope you are correct. I'm pushing for 500k miles on my truck.
p.s.
I always used 5w30 because that's what the manual says.

 

This is off the Ford Fleet Website...
5W-20 oil is a thinner oil with lighter viscosity that creates less drag on the crankshaft, pistons and valvetrain. Additionally, the oil pump can pump thinner oil more easily, improving oil circulation. Any increase in fuel economy may not be noticed by the average motorist. Machined internal engine parts are more precise than the parts of 20 years ago. This means that clearances between moving parts are smaller and more exact. Thinner oil such as 5W-20 can flow more freely through the engine while still filling the spaces. Thicker oil is harder to push through the spaces between the parts. This causes the oil pump to work harder, which in turn increases oil pressure while simultaneously decreasing oil volume. A lack of oil volume results in a decrease of lubrication and cooling, which may decrease engine part life.

The lighter viscosity of 5W-20 oil flows faster at start-up compared to higher viscosity oils, which helps reduce engine wear in critical areas by lubricating parts faster. Valvetrain components at the top of the engine require immediate lubrication at start-up.

 

The Million Mile Van is the exception to this rule of course, but that van is the exception of a lot of rules... he hasnt changed his trans filter yet, according to ford that should have been done about 900,000 miles ago, he's let the same oil in his engine for 55,000 miles before changing it... If one of us tried that chances are, our engines would be cooked long before we hit that mark, it's a lot of hit or miss, and with that van ford hit it right on the bullseye!

 

I think one big diff with the million mile van is that he probably averages one cold start every 500 miles, which is different from most drivers. Likewise his trans probably shifts very infrequently while he just hums along the freeway. I still like that story.

I also use 5W20, Ford's recommended oil, in my E150 with 80000 miles and will continue to do so. Maybe if it starts burning or leaking oil in its old age I'll switch it to 5W30.

George

 

Well, its been 2 days since I switched, and I've not heard any hard pinging sounds starting cold. As for better mileage using 5-20 versus 10-30, if I lose ½ mile per gallon I'm not going to lose sleep over it since these trucks don't get good mileage to begin with. Currently getting ~17mpg.

I'm more concerned with higher ambient temperatures where I live. It hardly will ever get below 35°F during winter months of Jan-Feb only, but summers are brutal at 105°F and running the air at the same time. Just seems to me that going up to 30 weight would give me a little more protection.

Also, I found this statement:
Motor Oil Viscosity

 

And that was written by the marketing dept, not the engineers. The fact that Ford itself recommends 5W-50 for at least 3 different US Modular applications casts those comments in a rather dubious light. A primed oil system will circulate oil through the engine almost instantaneously regardless of viscosity, unless the the thicker oil is simply too cold to pump. When talking 0 deg F and above, the different in viscosity is minimal in regards to how fast it moves through the engine on cold starts.

Then there's the fact that many synthetic 0W-30 and 5W-30 have superior cold flow properties to Motorcraft 5W-20. The issue isn't as simple as some would have you believe.

I'll say it again, 5W-20 will be fine, 5W-30 will be fine, 10W-30 will be fine.