Just bought '03 FX4 5.4 with 150K miles and would like suggestions on what oil to go with. I do not have any idea what has been used in it previously and wondered if I should go with the 5-20 as I am not sure that is a great idea with that many miles on the truck. The truck runs great and still puts out a ton of power.

 

There are TONS of oil threads here.

Use the Motorcraft 5W20 semi-synthetic and a Motorcraft filter. You can get both at Walmart.

 

Thanks glc. This was my first post as I am newby. Thanks for the screaming "TONS".

 

Walmart sells Motorcraft filters?

 

Has for years.

 

With that many miles, I've heard that switching to a synthetic may cause the engine to develope a leak, or current leaks to become larger. The sludge from the dino oil around the seals will be "cleaned" by the synthetic and leak past.

Anybody have more input/knowledge on this? I'm not sure if that right.

 

Go with SWEPCO. No problems. No questions. They are the best by far. I use SWEPCO for ALL my gear lubrication needs on every vehicle I own. Check 'em out:
www.swepco.com
The best by far.

P.S. MudTerrain: don't switch to synthetic. No need. Synthetic oils are great with heat resistance but can't suspend zinc or calcium. two crucial additives needed in ANY oil. Synthetic is way over priced for what you get. Check out SWEPCO or Mobil Delvac: www.mobildelvac.com. Both great Oils.

 

Find out what the previous owner used and stick to it. It worked for 150K miles, it'll do just fine for another 150K.

Motorcraft 5W20 and an FL820S filter are guaranteed good to go items though.

 

x2

 

The recommended Motorcraft is a SEMI-synthetic and that's what the factory put in that truck and what they recommend it be serviced with.

 

They reccomend Motorcraft because Ford owns them!!!! they reccomend it because they want $$$ !!! Doesn't = best!! Not saying it's bad but definately not the best! Switching wont hurt, using better oil will only help!

 

Help how? The thread starter's truck has 150,000 miles on whatever oil/filter combination the previous owner used. How do you propose to better that?

 

In a word-no. Motorcraft is a licensed product manufactured or distributed through a publicly traded company known as Universal Manufacturing Company. They are traded on the stock exchange as UFMG. Ford provides the specs and Universal gets the finish product from Conoco-Phillips. For other parts, Universal will either manufacture under Ford license for the required parts, out source the parts to others to meet spec, or manufactures to their own specs for after market sales.

I don't know why you would say this when Motorcraft oils have always produced some of the industrys lowest wear metals. The CP basestock is known world wide as one of the finest produced.

Partially correct. Most of todays synthetics are a GP III dino basestock and will do a little better than a GP II but generally the engine is toast long before the oil breaks down with todays technology. Heat is not really much of an issue for oil anymore providing it meets Fords specs. GP IIIs and PAOs do not support the additive package- that's true. Both will use either a mineral oil for a binder or an ester. Either way, it works quite good. Ester blends do not require any binder as they suppport the add pack. Zinc and Calcium are not totally required in any formulation. Zinc wasn't even used until after WWII. It has remained in use mostly because it works and it's cheap. There are many others that will work in its place but not necessarily cost effective like Zinc.

I'm not sure why you are on a Swepco kick but from everything I've read at their website it MAY be decent oil for a diesel but that doesn't make it good for a gas engine. Any oil that has a service life in a diesel of 100,000 miles has got to have one heck of a high TBN. A high TBN in a gas engine will cause overbasing and oil useage will be the result because of calcium deposits forming on the cylinder walls. The only fix is a complete tear down and all static parts honed to get the calcium off- not a cheap fix. Swepco also does not show up on the API certified oils.

kaseylewis, since you have no idea what has gone into this engine, I would suggest using an Energy Conserving oil in 5w-30 of your choice that meets Fords spec 929. Note the fuel mileage for every tank of gas. If the mileage drops 1-2 mpg, the previous owner used a 5w-20 oil. You can, if you like, use this oil as a flush and short cycle the oil change say at 1800-2000 miles. If the mileage doesn't change, the previous owner used a 5w-30 viscosity oil. If the fuel mileage goes up, the previous owner may have use a 5w-40, 15w-40, or a high mileage oil. If that is the case, I would run the 5w-30 and see if oil consumption is an issue.

 

dang, labnerd did you memorize all that...

 

Shhh.. bud. Don't **** him off !

For myself - I'm just real glad he and Q are here

Thanks, guys.