What weight oil do you guys run in your 6.8's? Yes, I know the manual says 5w20, but man, that stuff is like water!! I have always ran the 5w20 since I have had it. I was told by a engine manufacture that i should run 10w30 in it. What are your thoughts?? What do you run in your Ex??

 

I use Motorcraft Synthetic blend 5w-20 oil in my X. I believe the closer tolerances in the newer engines require the oil to be thinner in order to reach all internal surfaces while running. If at any point when I've got over 100k miles on her and I see (oil) smoke coming from the tailpipe I may move up to 10w-30, for now I stick with what's called out in the manual.

 

I'm running Mobil 1 5w20 in mine with the Motorcraft FL820s filter. I wouldn't recommend going to a 10wxx as the first portion of the identifier is the winter or cold viscosity. Going to a thicker oil at startup or when it's cold is not a good idea. I personally recommend going with the manufacturer recommendation and just using a good quality oil.

 

I run 5qts of M1 5W-20 full synthetic with 1qt Lucas Full Synthetic oil stabilizer in all my MOD motors and never have had a problem.

 

I use same as Shafe76 with the FL-820s. I do a complete oil change at 5K miles and I change the filter at 2500 miles and add a quart. 95K miles with no oil related issues so far.

 

I use Mototcraft blend as well. Cant beat the price at Wally world.....$11.50 for the 5 quart jug!! Wally world also carries the Motorcraft oil filter. I am up to 117,000 miles now.

 

What tolerances in this engine is so close that anything heavier than 5w20 won't lubricate? I hear this a lot but never any specs to back it up. I have a 2001 F250 that has had mobil 1 extended performance 15w50 in it since it was new (5.4 engine) but now (as of the last oil change) I'm using mobil 1 extended performance 10w30 simply because I can't find the 15w50 any more in my area. My engine (78000 miles) is as quiet and solid as when it was new.

 

I once posted specs of the main bearing and other clearances of the V10 versus my Yamaha Royal Star Venture's 1294cc V4.

Now my bike calls for 20w-50 or 10w-40 and has the same exact main bearing tolerances as my V10 plus it has to lubricate my transmission. So the "use 5w-20 due to clearances" arguement is crap, IMO.

 

i've been using motorcraft 5w30/5w20 for 67,000 of my 75,000 miles on my F250. i use either a motorcraft/wix/napa filter, just depends on what they have where. when i bought my last oil at wally world (yep 11.79/5qt jug), they were out of motorcraft filters. so i headed down the road to napa (had to go that way anyway). i've been using napa for a while now, and one reason i keep going back is the price they give me on filters. not to much more than wally world, bout $0.80 more than a motorcraft.

i use the same thing on my Excursion, motorcraft 5w20 with motorcraft/wix/napa filter.

 

I use motorcraft 5-20 from walmart. I used mobil 1 and started consuming oil so I switched back to motorcraft. The bus has 178,000 on it and still going strong.
Joe

 

Mobil 1 5W20. Wouldn't run anything but Mobil 1. Spent some time in a petroleum lab a few years ago, and the lab supervisor told me that after the testing he did on dino oil and synthetics, he won't run anything but synthetics in his personal vehicles. Good enough endorsement for me.

As to the weight, I guess I'm just going to trust the guys that designed the engine to suggest what weight oil is appropriate, rather than compare bearing tolerances to a motorcycle engine and decide that I should run the same weight oil. (Not meant to be a slam, Monsta, just stating that there's probably a few other variables between the two engines that could effect the viability of your comparison).

Call me silly, but what possible advantage could Ford gain from having us run a lighter weight than appropriate oil in our vehicles? Mileage doesn't matter, these were not in the overall manufacturer calculations, I don't believe?

 

My comparison was not to justify me using the same oil (Shell Rotella T 15w-40) that I use in my bike for use in my truck. FWIW, I use Motorcraft 5W-20. The example was to debunk the whole "tighter clearance" issue. You do not need a 5W base oil "to get to all the lubricated parts".

The reason my bike uses the "heavier" oil is for shear stability. Actually there's a strong argument for it's use in modern truck engines as well but that's another discussion.

Standard factory fill.

When you produce hundreds of thousands of vehicles that all come filled with oil you don't need a bunch of different types/weights. Same with dealerships.

Ford calls for 5W-20 in virtually every gasoline engine it produces for the NA market.

But Motorcraft 5W-20 is a very good, very stable oil. The further the numbers get spread apart (actually by a factor) the more susceptible to viscosity loss it is due the oil having a greater amount of Viscosity Index Improvers (VII). So 5W-20 is more stable than 5W-30. And 10W-30 more stable than either. But I digress...

I believe regular change intervals and a quality filter is honestly more important than the oil brand. If you use Brand C's "Recycled Oil with Liquid Candles" of the proper engine manufacturer's suggested weight but change it before it degrades what's the big deal? Well....that change interval may be every 1000 miles but that's another discussion as well...

Bottom line really is you cannot go wrong using 5W-20 or 5W-30. Both were specified for use in the V10. 5W-20 superseded the 5W-30 suggestion but nothing changed in the engine.

 

i use Mobil 1 5w20 synthetic in mine. with either a motorcraft or K&N oil filter.

i switched it to synthetic when i bought it at 80k miles. since then i've logged 12k miles and 3 oil changes with no issue.

 

Good comments all. The mileage item may not be a factor on our Ex's but it is supposedly one of the main reasons for 5w20 and 0w20 oils coming into the market. I've never bothered looking for a study to see if they truly made a difference or not. At my shop we use the manufacturers recommended oil unless the customer requests something different. I know having additional oils makes it a bit of a pain to do inventory and store it all!

 

I just changed oil and filter today. I put on a wix filter and motorcraft 5-20 semi synthetic. I had the ford oil for awhile, so I used it. I have been running 5-30 mobil 1 because the Costco up here only carries the 5-30. I used 1/4 quart of Mobil 1 in 3000 miles. I will go back to mobile 1 next oil change. The motorcraft oil was free so I couldn't resit. No switching back and forth from full to semi synthetic wont harm your motor. I've done it for years. The Big blue whale (Ex) doesn't mind it at all. No leaks and 105,705 on the clock.