i have my 2001 4x4 f-150 with 76,000 miles on it. I have heard about people that really like synthetic oil. I have been running the motorcraft 5w-20 synthetic blend since i had it and want to go full syn. I have heard that it could make my seals leak??? dont know if thats true. Also what kind of synth. oil do you guys recomend?? I heard 5w-20 royal purple was good?

Thanks

 

Royal Purple is a good brand. I use Mobil 1. Synthetics are not good to use if you are breaking in a motor. But with the mileage you have you should be fine.

 

this post comes up about every 3 months. normally gets a lot of guys going because everyone has their own "special" brand of oil and filters they like. fact of the matter is it really dont make much difference what you use. the Motorcraft 5-w20 is a good oil, meets all the new specs. So do 10 other brands of dino oil. The synthetics are good also. If you run 3000 miles month and want to extend your time between drain intervals, thats something to consider. If you put 5000 miles a year on the truck or do a lot of mud/ dust/ high humidity conditons/ dont bother with the synthetics thinking you can run the truck 10,000 miles or two years between oil changes, that would be dumb.
it really depends on what kind of drving you do and how many miles you put on in a year.

 

It was here, on this very forum, about 3 months ago that I learned something no one had ever explained to me.... that you change oil because it gets dirty, not because it wears out! I know, many of you think it is common knowledge, but for me, it was news. I alsways thought they "broke down" after 3000 miles.

So, I tried a synthetic blend once and then went back to my favorite Catrol 5w-20 with a motorcraft filter and 3000-4000 (depending on when I get to it) oil changes. 126k on my engine, burns no appreciable oil and runs like a top. I'd stick with what got you to 76k if it is working. Isn't there some saying about if it ain't broke...

 

I run 5-20 Royal Purple, and have run Mobil 1. My truck burns a little more than a quart or better with regular oil, about 1 quart with mobil 1 and 1/2 a quart with Royal purple every 3000 miles. If you have any oil leaks dont bother with a full synthetic because it will most likely leak more.

 

You've made it that far and this long on Motorcraft 5w-20. So why switch, there is little to no difference from changing to other oils in terms of benefits. If it is used to that oil keep it on the same kind and schedule along with Motorcraft filters, this should more then meet the needs of just about anyones truck.

 

Why switch? You can get Motorcraft filters and oil at an affordable price at Walmart. Keep the oil and filter replaced, you should be good to go.
The MC synblend is good stuff in my opinion.

 

Exactly!!!!!!!!!!!!!!!

 

I find synthetic a waste unless you are running extended drain intervals, and I doubt it will give you any lubrication advntages except in turbo applications where you can get huge heat build up. I use cheap dino (Castrol GTX) and run the heck out my engine, still going strong and internals are spotless.

 

Important additives in motor oil do wear out & oil filters do a good job at preventing oil from getting dirty. Oil breaks down & becomes chemically contaminated. There should be virtually nothing in terms of outside dirt getting in. Running dirt roads or the super slab shouldn't make much difference. However frequent short trips, loads of stop & go driving, or regular heavy WOT hauling equate to severe duty, requiring more frequent oil changes than easy, light duty, commuting.

Older motors are in the process of becoming broke.

For these reasons oil companies developed 'High Mileage' oils specially blended for older motors. IMO they deserve a look.

I've had leak problems trying switch to synthetic oil. I understand that over the years seals have been improved reducing this phenomenon. IMO it was not a myth that switching to synthetic was responsible for leaks.

The 'High Mileage' oils have the opposite reputation. They claim to revitalize marginal seals & extend their useful life.

Switching from synthetic blend to full syn may be splitting hairs & there's something to be said for using MotorCraft products. However IMO a major benefit of synthetic is extended oil change intervals. It becomes mostly a cost to benefit ratio. Early on synthetic was promising 50,000 miles between changes! At some point regular oil & regular intervals are going to out perform synthetic if extending oil changes.

I've used Mobil 1 & Amsoil, but do not recommend any synthetic motor oil. Not that I'm an 'oil is oil' advocate, but there's probably more difference in price than performance among the major brands.

 

Just to add to what Club said, a high mileage will have swelling agents added to the oil. Also, some synthetics that contain poly-ester base (redline) will also reduce leakage to a certain point if the seal isn't damaged.....BITOG is great site if you want to learn more about lubricant properties and chemistry. Most "syns" contain PAO and Grp III base stocks and have no seal swelling properties, so long as you have no leaks, a synthetic oil won't harm factory seals.

 

Just to clarify, I did not imply synthetic oil would "harm factory seals" only that trying to switch an older vehicle over to synthetic may result in oil leaking.

Nor did I imply there were no 'High Mileage' formulated synthetic oils, only that oils blended specifically for high mileage are worth a look in the typical 75,000+ mile range.

In many cases where switching to synthetic oil caused leaks, switching back often stopped the leak.

 

Nobody said that you did.

 

I would like to see these cases you are talking about. I have went back and forth between synthetics and dino oils without any effects what so ever......that is simply just a myth. Once again, if your seals are in good condition you do not have to worry about leaks.

 

""I have heard that it could make my seals leak???"'

No, about as much as flies cause garbage
bruce