Preferred Engine Oil Viscosity

C

caucapon

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For the last decade or so, Ford has recommended either 5W20 or 5W30 engine oil for most of its engine including the 4.6 L. I'm curious which oil is the most popular here. Since the owner's manual specifies the 5W30, I would guess that viscosity is the most used.

I'd also appreciate knowing how satisfactory your extended use experience with these two oils has been. Have there been true practical pros (better fuel mileage, etc.) or cons (lower oil pressure, etc.) associated with one or the other.

I know that many people have powerful feelings regarding viscosity, manufacturers, oil change intervals, and so on that are frequently based on emotion or casual science. I would prefer to avoid such opinion if possible. Just trying to decide which viscosity to use in an engine with fewer than 10,000 miles.

Are there cogent reasons for using one or the other?

As always, I thank anyone willing to respond.
 
i use mobil one 5-30 in my 97 lsc, and motorcraft synthetic blend 5-30 in my 98 lsc.
i cant tell ya anything more than that, its oil, thats what i use, and it does what its meant to do !!
 
It is good to understand what "5W-30" means. These are multiviscosity oils as opposed to a "strait" 30. When it is cold the oil is a lower viscosity '5W" to allow less resistance, better oil flow, faster warm-up, and less wear. When it warms up it then performs at as a 30W. Here are a few good web articles describing to. Best bet is to stick with what the manufacturers recommend for a stock engine since their scientific testing is a bit more comprehensive than ours.

http://www.blackstone-labs.com/oil-viscosity.php

http://members.themotoroilevaluator.com/index.php?id=144
 
once a year !!!!!!!!!
your motor must look like this inside...
head3.jpg

head2.jpg
 
No actually true synthetics keep them very clean, my family does the same intervals with all 5 high mileage cars, never had a problem and the only tear down we did was clean (head gasket).
 
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NO way Jamie....don't blame the mileage.....thats a Penzoil engine! When I worked at the car dealership for awhile, we kept getting cars from the Florida auctions that had bad cams. Turns out, we had bought about 15-20 Camry's, Sienna's, Pathfinders, and a couple Navigators that were ALL from Florida then needed to have the cams replaced or entire engines. First the owner was blaming the buyers for picking crappy cars, then he was blaming the shipping companies for doing something during shipping.

Well, after trial and error and noticing that all the cars resided in Florida, they began to notice that ALL the cars had Penzoil oil filters, "reminder" stickers on the windshields, and even Oil Stop license plate frames. Most of the cars were prior rental vehicles so the rental/lease companies would just do the basic Penzoil Jiffy Lube type oil change.

I will NEVER EVER use Penzoil in an engine....or it will look just like that one.

Oh...so it turns out, Penzoil carbonizes and clogs the oil passage ways in engines with small oil passage ways (i.e. Camry cams, Pathfinder heads, Navigator bearing journals), eventually running the bearings dry and seizing a cam or causing a rod knock.
 
Max (and others) have done the Black Stone Labs tests with their vehicles. Max can chime in and correct me if I'm off, but his Crown Vic has 250k miles and he just recently sent his Black Stone Labs kit in for testing. The return was spectacular, so much so that the lab commended him for having such a clean, high mileage engine. They also recommended/suggested he does not need to change his oil for up to 10k miles.

He's also done the same on his Vette and they suggested changing the oil in that every 6-8k miles.

Time has nothing to do with your oil....3 months/3k miles doesn't make sense. So if I have a bottle of oil sitting on my shelf for 3 months, I have to throw it away?!

Back to the thread.....I've always used Gastrol GTX 5w-30 just because the Amsoil guys showed that as being WAY up their on the "list of good oils" and its reasonably inexpensive. I change my oil by "eye mileage". If its getting dark, I change it.
 
I use full synthetic oil once a year in all the cars now if they need it or not. Royal Purple 5-30 in The Mark and Mercedes, and Mobil 1 Extended Performance 15k mile formula 10-30 in the Town & Country. Like I said, I change the oil in all 3 cars at least once a year. Wendy and I both work from home, so we don't put many miles on the cars. The Mark has a new motor with maybe 10k miles on it, the Mercedes has around 140k miles, and the T&C is just shy of 110k miles. They all seem to be running good on this schedule. :)
 
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Ya know, I see many others have weighed in to give their opinion, and thats all well and fine but I didnt see anyone say anyone say anything about oil filters. FWIW, I much prefer 5W30 Mobil One or Castrol Syntec full synthetic or even Amsoil full synthetic, but if you are going to use as light as 5W30 viscosity, a quality filter with a decent bleedback valve is a must. Otherwise, the oil bleeds back into the pan after shutdown, and there is no oil pressure on the cam tensioners for a few seconds after start up. This of course causes needless wear on the cam chains and gears. I believe it was just last week when someone posted about an engine that jumped timing. I use ONLY Motorcraft, Wix Premium or Baldwin filters. Most usually Motorcraft as they are available at Wallyworld, and I change my own oil. It was last changed 3/1/10 but it onlly has about 900 miles on it since then.
 
whiplash15 said:
I much prefer 5W30 Mobil One or Castrol Syntec full synthetic or even Amsoil full synthetic.
Click to expand...

Hi Whiplash,

Back in 2007, you stated, "I have used 5w20 for years. You will notice a BUTT-O-METER improvement in acceleration. Seems like the engine runs freer."

Have you switched to 5w30 in recent years? If so, why?

Appreciate your input.
 
Interesting.... As an afterthoght, I was thinking about adding similar info. I am using 5W30 in my present car, as it has 150K miles on it, and requires a little more TLC. Also, I guess that shows that I am an opinionated kinda guy. I dont know if thats good or bad.
 
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If your doing extended intervals then a good filter is a must for sure.

On another note, im pretty sure there are only three true synthetic brands out there Amsoil, Mobil 1 and I think Redline. All of these are made from natural gas, not oil like castrol and valvoline "synthetics". Somehow they are able to get away with usig the term synthetic to just mean a high grade petroleum.
 
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Don't know what the inside of my engine looks like but it has over 140k miles on it with no engine related issues and it is 14 years old. The one year interval vs what the oil monitor says is also what is specified for my Corvette with Mobil 1.
 
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Most oil filters nowadays come with bleedback valves. That's the newest trend.

Whiplash...that thread about jumped timing is turning out to be something completely different. The original poster was jumping to conclusions.
 
Check this out to see how your oil did in this test:


http://www.animegame.com/cars/Oil Tests.pdf


See what Mobil 1 has to say about this kind of test:

http://www.mobiloil.com/USA-English/MotorOil/Car_Care/AskMobil/Oil_Film_Strength.aspx


See what Royal Purple has to say about this kind of test:

http://www.royalpurple.com/rp-performance-advantages.html

lol Like I said, I use both products, and will continue to do so. My preference, but I just like the idea of using the Royal Purple in my cars that have overhead cams - just because of the film... :)
 
After readig the whole shebang, I feel like I need to try Royal Purple (or grape juice as we used to call many years ago).
 
Synthetic mobil one is what I have in my 98 mark 264000 miles. I just moved from Md to N. Dakota and now I drive hardly any. Unfortunately I will have to allow someone else to change my oil but I will be watching!
 
I'm using Wal Marts best synth 5w30! Change it every 6 moths whether it needs it or not.....
 
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