Hey I just got a 2001 gt and am going to be changing the oil in it. I am planing on either using mobil 1 or royal purple. I am thinking about going with the 5w-30 instead of the 5w-20 because its a little thicker. I also heard the only reason the 5w-20 is recomended is because it helps fuel economy. So who uses 5w-20 and who uses 5w-30 in there 4.6's and why?
who is using 5w-20 and who is using 5w30?
- Thread starter LB0193
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Motorcraft synthetic blend 5w-20 and Motorcraft filter.
Check this thread out for more information on oil people use. This was recently hashed over quite well.
http://forums.stangnet.com/showthread.php?t=599777&highlight=oil
Check this thread out for more information on oil people use. This was recently hashed over quite well.
http://forums.stangnet.com/showthread.php?t=599777&highlight=oil
I use Motorcraft 5-20 synthetic blend. Why?
-1- It's what Ford recommends to protect my warranty.
-2- The used oil analysis results I have read are better for Motorcraft 5W-20 than for 5W-30.
-3- I live in frigid New England. If I lived in Florida, I would probably consider a higher weight oil.
-1- It's what Ford recommends to protect my warranty.
-2- The used oil analysis results I have read are better for Motorcraft 5W-20 than for 5W-30.
-3- I live in frigid New England. If I lived in Florida, I would probably consider a higher weight oil.
03ghoststang
Well-Known Member
MineralMan
Active Member
PlatinumDevil
Member
5w20 nonsynthetic castrol... why... because synthetic is expensive, and my car has never had synthetic and switching is bad for some reason.
ponysarepretty
New Member
- Jul 25, 2005
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PlatinumDevil said:
that is unwise, the original oil is at least semi synthetic, and swtiching has done me no harm.
castrol syntec 5w20
ponysarepretty said:
No. "Stupid" is insulting people on the Internet. Insults have no place in a Tech forum.
Crzyhrse
Active Member
Mobil 1 Synthetic 5W-20. Why? Because the owners manual says to use 5W-20, and I've been using Mobil 1 Synthetic for 12 years. 
ponysarepretty
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Actuall if the oil cap says 5w-20 on it then it is very wise to use what it says.
1. when they changed over to 5w-20 the bearing clearances were closed a little and it takes a thinner oil to get around to all the journal.
2. it has to be thin to properly lubricate the overhead cams when cold.
I have worked at two Ford dealerships for almost a year and a half combined. I have seen three engines with spun bearings. We couldn't understand why, head gasket good, intake gaskets good, proper maintenance, grandma driving, BAM 5w-30 was put in the motor.
IMO anything but 5w-20 is playing fire with a expensive engine.
1. when they changed over to 5w-20 the bearing clearances were closed a little and it takes a thinner oil to get around to all the journal.
2. it has to be thin to properly lubricate the overhead cams when cold.
I have worked at two Ford dealerships for almost a year and a half combined. I have seen three engines with spun bearings. We couldn't understand why, head gasket good, intake gaskets good, proper maintenance, grandma driving, BAM 5w-30 was put in the motor.
IMO anything but 5w-20 is playing fire with a expensive engine.
40th GT
New Member
I've been using 5w-20 all along and I will for a long while but I have to ask you this: If the bearing clearances did get tighter, why do you think that Ford never addressed it in the TSB regarding the oil weight change? (or have they??) Because if they have addressed it, I think that more people would be running 5w20 right now instead of anything else.Sncbluegt said:
They changed it around due to the CAFE recommendations. You could still run 5w30 (plenty of people do,) but supposedly it's not required.
Honestly, run what you feel like, but if you run other than whatever the manufacturer recommends during the warranty period, and something breaks bad, expect them to blame the oil. I go by the advice of veterans on both the 5.0 & 4.6 side.. and that's: Run the thinnest you can yet still maintain adequate oil pressure at hot idle.
I run 5w20, I live in Arizona where ambient road temps are about 140 during the summer, and have never seen a reason to run thicker at operating temp. That seems to be the claim.. "run thicker in the summer to keep pressure up." My Autometer gauge never goes below 25, and that's far more than required by Ford specs.
Honestly, run what you feel like, but if you run other than whatever the manufacturer recommends during the warranty period, and something breaks bad, expect them to blame the oil. I go by the advice of veterans on both the 5.0 & 4.6 side.. and that's: Run the thinnest you can yet still maintain adequate oil pressure at hot idle.
I run 5w20, I live in Arizona where ambient road temps are about 140 during the summer, and have never seen a reason to run thicker at operating temp. That seems to be the claim.. "run thicker in the summer to keep pressure up." My Autometer gauge never goes below 25, and that's far more than required by Ford specs.
Marks5.0!
Founding Member
If I'm not mistaken, the initial # in the oil description, whether it be 5,10, 15, or 20 is the actual weight of the oil. (5W30), (10w30), etc. the second # is the weight value of protection it offers when engine operating temperature is reached, due to the chemicals it contains.But i could be wrong.....And it should be common sense that oil can't get THICKER as it gets hotter, LOL.
OH- 5W30 royal purple + wix filter showed 2rwhp gain on mustang dyno, but conditions could have been a contributing factor.
OH- 5W30 royal purple + wix filter showed 2rwhp gain on mustang dyno, but conditions could have been a contributing factor.
silvergt2001 said:
Here's a quote from ASE to help you out.
"The viscosity grade (a fluid's resistance to flow) is rated at 0° F (represented by the number preceding the "W" [for Winter]) and at 212° F (represented by the second number in the viscosity designation). So 10W-30 oil has less viscosity when cold and hot than does 20W-50. Motor oil thins as it heats and thickens as it cools. So, with the right additives to help it resist thinning too much, an oil can be rated for one viscosity when cold, another when hot. The more resistant it is to thinning, the higher the second number (10W-40 versus 10W-30, for example) and that's good. Within reason, thicker oil generally seals better and maintains a better film of lubrication between moving parts.
At the low-temperature end, oil has to be resistant to thickening so that it flows more easily to all the moving parts in your engine. Also, if the oil is too thick the engine requires more energy to turn the crankshaft, which
is partly submerged in a bath of oil. Excessive thickness can make it harder to start the engine, which reduces fuel economy. A 5W oil is typically what's recommended for winter use. However, synthetic oils can be formulated
to flow even more easily when cold, so they are able to pass tests that meet the 0W rating. Once the engine is running, the oil heats up. The second number in the viscosity rating--the "40" in 10W-40, for example--tells you that the oil will stay thicker at high temperatures than one with a lower second number-the "30" in 10W-30, for example."
