True, but only when the oil is hot. As I understand it, with respect to startup and startup only, the 0 grade will certainly flow to critical parts faster than a 5 weight. Regardless, both are so thin, I think it is splitting hairs.

This is the Twenty four dollar question. IF the tolerances are different....that is the question no one seems to be able to answer and back it up. I have no problems with 20 wt. oils. I have 4 cases of the stuff in the garage.

This question leads to further questions for me anyway. Why is it that when these motors start using oil, many mechanics and dealers start recommending using a thicker oil? My neighbor, for instance, he drives a 1999 with a 4.6. He now uses 10w40 Royal Purple and is loving it. But how a truck "feels" when it drives isn't the best measuring stick, IMO, for how well the motor is being lubricated.

I've always heard to go to a thicker oil when the motor is using oil. These motors keep stacking up the miles well into the 6 figures. So, what do we make of that?

 

ppl are not fond of the 20 Visc. You might be right that the higher viscocity won't damage the engine. But what I am looking at is the economic impact of a bad choice or going against the manufacturers recommendations for a newer truck. 1999 F150 with a hypothetical value $4000 versus an average price of $25000 for a newer F150 truck. Exprimenting with a 25k truck is really not wise decision, but it is your money and your truck.

 

After a combined total of 115K miles in 3 different motors requiring a 20 weight oil but using a 30 weight oil, I would think that any damage would become apparent by now.

 

I'm not sure about the 04 and ups, but on the 97-03's 30 weight is not going to hurt them.

From 97-99 or maybe 2000 ford recomended 5w-30. Then all of a sudden in either 2000 or 2001 they switched to 5w-20. Why? Because of fuel mileage and emissions. Are the motors different? Nope. They are exactly the same motors.

I'm sure ford just stuck with the 5w-20 for the same reasons in the 04+. When a vehicle calls for 5w-20 switching to a 5w-30 is not going to hurt anything. The difference is so small that the motors will never know the difference. Anybody who thinks that going from a 20 to a 30 is gonna mysteriously blow up their motor is wrong.

I just called my local dealer for the heck of it to see what they recommend. This is for 04+ remember, they said in the winter time or normal driving 5w-20 will work fine. He told me that if you are doing any heavy hauling or towing in the summer they recommend going to the 5w-30, even though they recommend 20. I asked him if it would hurt the motor going to a heavier oil than recomended due to tighter tolerances. He just laughed and said no. He said going to a 20w-50 or something may cause problems way down the road, but a 30 isn't gonna hurt anything.

 

Rock Crusher,

When we bought our 2005 Honda Odyssey, we were told that the motor requires 5w20. The manual concurs. Honda obviously makes 5w20 and 0w20 oil.

However, the service manager, and several of the techs told us to use 5w30 in the summer and 5w20 or 0w20 in the winter. When they saw that we had installed a towing hitch, they recommended the 30 wt. oil if I planned on towing on a frequent basis.

I asked about warranty and the 20 wt. recommendation. Answer: "That is a joke, that is for fuel CAFE requirments. Your motor is better protected with the higher viscosity. We'd stand by our recommendations if anything ever happened to your motor."

I asked him to put it in writing, and he did.

 

These manufacturers are confusing everyone

 

They are FORD and at the time the tolerances in these motors were a huge achievement for a mass produced engine let alone a modular OHC motor.
The fact that the improperly stamped mustang dipsticks were never recalled is not a moot point.Oil level was still acceptable as long as it fell between lines which is the point.Thats why it was only a TSB.
Sorry Ow30 is thiner,keep thinking 10w 30.
If you don't have the specified oil in a motor all bets are off when it comes to any warranty work related to oil associated parts.If you call and ask a dealer thats you will hear.
I was around when the machines were being built and debugged if specs including tolerances are to far out on the samples the company refuses delivery.And tolerances were an issue.

 

Want to tell a certified mechanic how I'm going to check to make sure you've been using the proper oil? I don't know of any mechanic or garage that will shell out the money for the equipment to check viscosity.

 

Easy - they can ask for oil change receipts. If you don't produce them, warranty claim denied, no proof that you even changed the oil at required intervals.

 

And if you changed your own oil? Got the filter and oil for free? Paid cash and didn't get a receipt due to printer being out of paper on those days? etc. etc. etc.

It is very hard to deny a warranty claim. There has to be irrefutable physical evidence.

One more thing just for fyi... original filter on all fords is completely white, no markings.

 

I said to dump it before he brings it in not prove he had the right oil in it.If ford has to pay they will check the oil and tear it down.Anyone can mail out motor oil to be tested for a multitude of components.On a $6000 motor you can bet on it being tested by ford.I wouldn't show up with fresh oil either.

 

0w-30, 5w-30, 10w-30 are all 30 weight at engine operating temp. The first number is cold start up weight. The change is effected by viscosity modifiers (polymers, etc) that uncoil or elongate when heated. Motorcrafts 5w-20 is fairly close to the bottom range for most 5w-30 oils. It is not too thin as some have claimed. I use Amsoil 0w-30 and have 110K miles with zero engine problems.

 

GEEZZZEEE... Just use what is 'spec'd' for your specific engine and deal with it...... OMG.... My oil fill cap says 5w30.... That's what I run..... Sure, FORD said I can use 5w20........... I ain't gonna use it however..... If my oil fill cap said 5w20, then that's what I would use.....

When I drain my 5000k 5w30 oil, it comes out like water! So, it's pretty thin on it's own!

Whatever.... I don't know why I keep responding to these dumb 'oil' threads anyway!! I guess I'm just addicted to this....

Mitch

 

Hey Mitch -you should hook up to that trailer and head up here to the Mellon Fest. - You can anchore here

 

LOL

I use 5w30 and no problems either... Like Mitch said, I'll just use whatever it says on the oil cap, if it said to use no oil, I would do so... the warranty on my truck is over a LONG time ago