Guess I will start a controversy. I am old school and being a boater have towed with Ford Trucks for years. I like my oil to have some backbone to it to cope with extra heat and stress of todays engines. (especiallytowing) So Here Goes. I have been using 20w50 for years in my ford trucks and my 95 5.0. (I recently Ordered a SC Roush Mustang I plan to use it in as well.) In the winter I do drop back to 10w40. Here in the Ohio Valley the heat and humidity can get bad.

I also change oil every 2000 to 2500 miles or 3 months which ever comes first. Don't drive a lot of miles. I know why the manufacturers are using the thin stuff but I dont like that water. I realize heaver oil produces a little more resistance but when I drain a warm engine my 20w50 is pretty thin as well.

Well there it is guys - I said it - I am sure many of you will tell me how wrong I am. Lets keep it friendly - and have at it. Thanks.

Steve Fetter
Louisville, KY

 

i thought the tolerances in the 3v motor were too tight for anything thicker than a 5w-20. If thats the case... enjoy the short time your engine runs!

I learned my lesson with my old dodge 5.2 liter... I used to put 20w-40 in it cause that is what the company i worked for had on hand... When i quit and started buying oil again i went with the usual 10w-30... and wow! the truck was more powerful... less resistance... faster revs... cooled off quicker... i learnedthat just cause it is thicker doesn't make it better...

 

You are correct. The dealer down the road has replaced a few engines that they unknowingly put too thick of oil in. They thought 30W was OK. The 50W may blown some seals with the added oil pressure. Remember, added oil pressure means LESS oil flow. 50W may actually starve the engine of oil in our case.

 

It really has nothing to do with tighter tolerances but it does have something to do with the Variable Cam Timing Solenoids and making CAFE Standard for fuel mileage. I would not run anything thicker than a 5w30 in the 3V Engine.

If you destroy that engine from running the 20w50 Ford will NOT cover it under warranty.
These are not Old School Engines. It's time to Re-Educate yourself. These are not OHV Engines.

Richard

 

I thought about saying it, but ..............you did.

 

If you destroy that engine from running the 20w50 Ford will NOT cover it, and If you destroy that engine from running the5W30 Ford will NOT cover it also.
Tighter tolerances is the only reason Ford engineers recommend and Ford Motor company mandates 5W20. A 30Weight oil does not want to fit in the same space that a 20 weight oil will. You can make a 30 fit but that will require a higher pressure. At a Idle or just cursing there will be no problem, But when you put your foot in it and the oil system is straining to keep up with 5-20, it will be hard pressed to keep oil where it should be with anything thicker.
Back when Main bearing clearances were 2.5 thousands 20W50 was the thing to run. Now you try to force 20W50 threw 1 thousands clearance and you can see that no good could come from this.
The reason Ford made their tolerances tighter is long life. A 4.6 with 100,000 miles on it will have close to the tolerances of a new engine requiring 5-30 oil.
Everyone has a different opinion on what is and is not good for a oiling system. I would say take what every opinion makes you feel good.

 

Don't ever let Roush know you put in 20w-50[&:]They will attribute any engine failure to improper oil used. 20w-50 is pretty thick and since most wear occurs at startup, that's where most of your wear will occur as well. 20w at room temperature will take longer to circulate than the the 5w and a 50 weight...you'll probably have some parts of your engine (like rod bearing or mains) that don't get proper lubrication.

20w-50 is great for older pickups and such but new cars (and trucks) have much tighter tolerances. Try fitting a .050" feeler guage into a .030" space. Just doesn't work. Same goes for oil.

 

It's not about fuel economy folks. Let's not forget that Ford WANTS 30W in the 6 bangers.

 

Well Guys, I have been doing a lot of reading including all of your comments and I hate to admit it but, it looks like I have been living in the past. The general idea seems to be that the thinner oil is better for todays engines. I want to take care of my Roush right so I will use the 5w20. Just hard to get used to the idea something as thin as water (almost) is better for your engine.

After seeing some things on the net that caught my attention - I knew if I posted what I have been using and what my old school thinking was I would get some responses from some people who were more up to date on oil tech than I. Thanks.

I am hesitant however to change much lower than 10w40 on my 5.0 (12 years) and the 4.6 (7 years). I have had no problems with these engines whatsoever in relation to oil. As I have said - I went with the heaver because of towing with the expedition, and the 94-95 mustangs tend to run hot. I would be concerned that droping the weight that much after all these years could create problems. Thank you again for your information!!

I like to think that I am never so smart that I can't learn something from someone else!!

Steve Fetter
Louisville, KY

 

I've recently been changing my oil with 10w-40 here in AZ on my 00 mustang. 114K miles and counting. Those tolerances aren't as tight as they used to be.

I agree that as an engine gets older it's fine to change to a higher weight.

For the first 60-80K miles though5w-20 or 5w-30 tops.