What oil viscosity is everyone using? [If you've changed it yet, of course]

[mikeelia]

I've only changed mine once and put the 5w-20 in, which seems like water. I know that some manufacturers insist on thinner oil to improve mileage and power, but I would think with our engine's windage tray that would be less of a problem.

I am worried about the long-term with such a thin oil, especially when summer really hits. I've always used at least 10w-30 on other cars despite what the factory says.

What does everyone think?

Mike Elia
05 GT lime
87 Bucik Regal Turbo T [garage queen]

 

[nbk13nw]

Just did my second change at 5K. Using 5-20 Synthetic.

 

[subzero05]

5-20 here also

 

[ctfordguy]

I have an 04 F150 and Ford reccomends the 5W20 like in my mustang. I did not change the weight in the truck and will not change in the car. Ford could deny you warranty if there is a oil related failure and the oil in the engine does not meet Ford spec - WSS-M2C930-A.

 

[ZenGirl35]

I've used 5-20 synthetic in my 04 GT since the second oil change and will continue running that in my 05 GT girlie when she arrives.

 

[Yamalover]

I had an 04 F150 and have an 05 now and 5w-20 is what is recommended and I had no problem last summer here in North Carolina. Using a heavier oil can have an effect on the oil pressue in the motor. North Carolina State Police put some 10w-30 in their Crown Vics and in some high speed chases and they built up too much oil pressure and it literally blew the oil filters off of the motor and grenaded the motor. Believe me Ford has tested these motors under all types of conditions and the 5w-20 is what they want you to use.

 

[mobydickdog]

Hey guys, it doesn't matter what kind of oil you use..............just make sure you use some.

I won't be using 5W-20 in Arizona I will guarantee Ford that. 10W-30 or even 10W-40 in Arizona. It doesn't get cold enough in Arizona to even consider using 5W-XX and really not even 10W-XX.

MobyDickDog

 

[Florida Bob]

5W20 here.

 

[Swede958]

As far as i knew, one of the reasons that mfgs use lighter oils is that the engines are so new and the clearances are so tight that a thinner oil is able to work it's way into the needed spaces easier than a thicker one. Yes, the lighter weight for mileage and power is true as well.

Consider this... would you feel comfortable buying a car, used, and putting in 5w-20 with say... 100K on the odometer? Probably not, why, cause it'd probably leak like a seive. As the engine gets older the lighter weight oil just can't cope with the expanding tolerances and a thicker oil is needed to fill the gap.

But this is only what I understand about things--- I could be wrong too...

The Swede

 

[zinn]

Hey guys, it doesn't matter what kind of oil you use..............just make sure you use some.

I won't be using 5W-20 in Arizona I will guarantee Ford that. 10W-30 or even 10W-40 in Arizona. It doesn't get cold enough in Arizona to even consider using 5W-XX and really not even 10W-XX.

MobyDickDog

Your engine is designed for 5w-20, puting a heavier oil in is likely to cause oil presure problems. if the oil presure gets too high and blows something say bye bye to you motor. a lquid will not compress and it will take more force to push a higher weight oil thru the system. once this force gets high enough oil will find another exit hopefully just a seal or blown oil filter but it could go as far as to break hard parts. if you were to run 10w-30 you would likely be fine but i would not recomend it. if you go go to something like a 20w-40 i doubt your motor would last 10,000 before you blow something, even in Arizona. but i didn't design the motor so i could be wrong.

 

[vmurh]

My wife's 2002 Mustang has about 47000 miles with 5-20. I am going with 5-30 from here out.

Ford does not care about your engine once you get past the warranty.

I had a 97 mustang that was hard to shift into 1st gear at a stop light and the dealer did so called repairs under warranty including new syncronizers. After warranty they did not care when the problem re-occured. I had a local transmission shop examine the car and the real problem was a warped clutch from the factory.

Car shifted great after that.

 

[Wiredawg1]

I love these forum mechanical engineers. Words of wisdom folks. Ford uses 5w20w oil for one reason, and one reason only. To help their fleet of vehicles meet CAFE requirements for fuel consumption. Does this mean that there is something different about the internal design of Ford engines between 1999 and 2001 when this oil requirement change was made, NO! 5W20 oil is not going to give you the protection that a 5w30, or 10W40 weight oil will give you. Especailly under hot, or high load conditions. And anyone at Ford that tells you that they will void the warranty if you don't run 5w20 is an ignorant fool. As long as you are running an oil that meets API standards, they cannot, by law void your warranty. I know it will not change most people's minds, so do what you want. But know this. 5w20 oil is not a good idea for high performance engines. Don't believe me. Go to the track and ask most racers what they run in their high dollar engines.

 

[mobydickdog]

Wiredawg1 is on target!!

What it boils down to is VISCOSITY. If you live in a cold climate, stick with the Ford recommendation. If you live in Arizona where its 115+ in the summer you better adjust.

And not to put words into Wiredawg1's mouth, but Ford has to come up with a one size fits all oil requirement for everyone, not just folks in Arizona or North Dakota.


Some light reading material.

http://auto.howstuffworks.com/frame.../automotive/auto_technology/2002/8/motor_oil/

 

[crash]

I love these forum mechanical engineers. Words of wisdom folks. Ford uses 5w20w oil for one reason, and one reason only. To help their fleet of vehicles meet CAFE requirements for fuel consumption. Does this mean that there is something different about the internal design of Ford engines between 1999 and 2001 when this oil requirement change was made, NO! 5W20 oil is not going to give you the protection that a 5w30, or 10W40 weight oil will give you. Especailly under hot, or high load conditions. And anyone at Ford that tells you that they will void the warranty if you don't run 5w20 is an ignorant fool. As long as you are running an oil that meets API standards, they cannot, by law void your warranty. I know it will not change most people's minds, so do what you want. But know this. 5w20 oil is not a good idea for high performance engines. Don't believe me. Go to the track and ask most racers what they run in their high dollar engines.

Interesting hearing about these forum engineers... Not flaming here, but it is funny to see an incorrect "ABSOLUTE" post like "One reason and one reason ONLY" after a snide comment toward those ignorant on the subject. There is a difference in ignorance and stupidity. I am NOT using the word stupidity here. Ignorance is the case, however, if you ask each member if they are right, they will insist they are.

CAFE is "Corporate Average Fuel Economy". These standards mean the entire Ford line must meet an average fuel economy standard. They way Ford (And others) address this is to offer economy cars with high fuel mileage to calculate into the equasion. (Hence the Festiva and Focus... ETC...) This has NOTHING to do with oil.

The reason 5/20 is used is because bearing clearances are tighter than ever. Getting oil to the top end is critical as well, but there is a reason... Main and rod bearing clearances are no longer measured in Thousandths or Ten Thousandths of an inch. They are now measured in MICRONS.

STICK TO 5W20. DO NOT adjust simply because you THINK you know better. Read the owners manual FIRST, then adjust accordingly. You MUST use the correct weight, but CAN use any brand under API approved specs.

 

[Wiredawg1]

Crash.. I don't want to start a pissing contest here, but you are flat wrong on this. Ford went to a lighter weight oil on the recomendation of engineers at Ford to slightly increase fuel numbers across the board in their entire fleet. Bearing tolerances have not changed in Ford engines since the oil reccomendation changes have been made. If you don't believe me. Check the engine rebuild specs, from 99 to 2004. It's a smokescreen that Ford has put up trying to get folks to buy their oil, which i'm not saying is bad oil. However, at that viscosity, you will not get the protection of a 30 or 40 weight oil, especially at high RPM use, which is how a lot of Mustang engines spend their lives. Contrary to popular opinion on this site, running a 5w30, 10w30, or even a 10w40 will not hurt your engine. Hell I know some people with Corvettes that run 0w40. Now that is a wide viscosity range, but you get great flow at startup, and superior protection at operating temperature. You cannot rely on owners manual information to get solid facts on oil. They give a recomendation, and 9 times out of 10 it's pushing you toward something that is going to help their bottom line. For a long time Motorcraft was the only game in town for 5w20, and not only that it was expensive due to the fact that it is supposedly a synthetic blend. Ford made a ton on that. Anyhow, I won't run it, based on what i've read, and my driving style.

 

[GTJade]

Okay fellas (and gals), I'd like to see some others weigh in on this (catch that pun). I, personally don't know the first thing about engines or oil! What I do know is that my first change is due and the more opinions, the better. Please post your opinions w/supporting rationale!

 

[crash]

It's cool. Not here to flame or argue, but try to avoid posting absolutes, as I am NOT totally wrong. I did NOT pull this out of my ass. This information came straight from the Ford engineers that trained me.

I apologize if I offended anyone... NOT the intent.

I agree all cars in the line may use the same oil, but to qualify for CAFE standards with the Excursion in the line, they need the Focus as well! These are two seperate issues.

I am certain there are other reasons for 5W20, including fuel mileage. I am not here to debate them, but have never used any weight other than 5W20, turbo or supercharged, with NO issues.

I do NOT rely on the OWNER MANUAL. In fact, have not read mine. Being an old school Ford Specialist, I will run what the Ford Engineers run in their own cars. Synthetic is definitely recommended, just make sure you are broken in first. That said, my first oil change was included in the purchase, and it got 5W20.

Ford CAN do metallurgy tests to verify you are running the correct oil. While not common, I have seen them deny engine claims in the past for this.

 

[RICVA05]

Reply to 5w20 wiredawg1 seems to be right

Check this website out www.performanceoiltechnology.com/ford5w20

 

[Wiredawg1]

It's cool Crash.. I just think people should read more on such things. I also think it's wrong of Ford to threaten, and sometimes even follow through with denying people warranty work based on our topic. I run full synthetic oils in all my junk, so that it remains running junk for as long as possible. In my junk that turns high RPM most of the time, (01 GT and my supercharged Seadoo waverunner.) I like to use a little heavier weight oil to get better protection. It's all in what your used to and what people say. And it's tough to change people's minds about things like this. I do however think Ford is doing folks a dis-service by putting a light weight, medium duty oil in high reving engines such as the 4.6 V8.

 

[ltccarndt]

5w20 Is a Honda Invention

Hello all, I had the same question when my wife got a 2003 Taurus, so I did some research.

Discovered that the 5w20 oil had its first 'paper' published in San Francisco at a SAE Forum (Society of Automotive Engineers) The study, done in Japan, for Honda and Toyota showed a 3%, on average, highway mileage improvement. About one half a mpg better for most engines.

Important note: the basis of the study was how to improve mileage, not how to make the engine last longer. So the trade off was very evident in the study: Sacrifice engine life to an acceptable degree to improve mileage. Read it for yourself.

The study focused on additional wear caused by the lighter oil and how it related to the increased mileage. The study showed the need for better main bearing alloys for the 5w20 to be successful.

The study is SAE number 982505 and is available for download for $12. I got to see it for free at the local engineering college where it is on microfiche.

From what I read it does improve mileage, you need the special alloy in your bearings, and if the temperature of the engine gets too high expect failure. In short, if everything in the cooling system is functioning at peak efficiency you will be OK. If not, for example, when the car gets a little older, it is really hot outside, or there is some radiator age--watch out.

Personally, as an enginner, and a SAE member who has now reviewed the data tables, I would go with 5w30 full synthetic oil. The 5 weight helps your engine at cold start up. If you can afford it and can actually find it for sale then go with the 0w30 full synthetic. For those who will race on a track, or drive in outside temps above 110F, then by all means bump up to the 40 weight. Mobil One has an excellent 0w40--this is the premier proctection for those who need it.

How to cut down on cost: I change my full synthetic oil twice a year, once in the spring in April and once in the Fall in October. Unless you put on a lot of miles, synsthetic only needs to be changed about twice a year.

PS, for those of you long term fans, I was the one with the terminal cancer, I had to sell the GT back to Bob Allen Ford, got a solid Ford 500 for the wife to ride off in the sunset in. And yes, it really hurt to turn in the keys.

That's my two cents worth , hope it helps a lot of Mustangs to a long engine life