I know the manual states grades, but doesn't mention Synthetic products, I think. My dealer says they always use Motorcraft 50/50 blend (syn/natural) in the 6.7's. What do most of you folks use and why? Thanks

 

Well, when mine get's it's first change. I'm going with shell rotella T6 5w40 sythetic. Some are saying to wait till 5000 miles to switch to synthetic. I mit do it at 3000 JMO

 

Shell Rotella T6 5W40. Always been a believer in synthetics.

 

I agree that the benefits of synthetic are huge and I don't wish to start a huge argument on this issue, but T6 is not a true synthetic... It is a Group III+ oil which is still mainly petroleum base stocks blended with synthetic.

Personally, I will be switching to AMSOIL (Group IV oil made from PAO base stocks) at 10,000 miles and adding a bypass filtration system.

 

FYI T6 Is full synthetic T5 is synthetic blend

 

Not sure what oil your dealer would be recommending since Ford/Motorcraft does not offer a synthetic blend oil that is diesel rated. Your only choices of Ford/Motorcraft product are 10W-30, 15W-40, and SAE 30 (would not be used in a 6.7L) for dino oil and 5W-40 for full synthetic.

 

I'm a huge believer in Synthetics and love Amsoil. It will be going in my rig soon.

 

I can not say that there is anything wrong with Amsoil, but it sure would be nice if they would actually API certify it rather then just making claims that it meets/exceeds certification. With the lack of a correct API certification there is always the potential for warranty related hassles with Ford should any oil related warranty claims need to be made...

 

I just confirmed on the Shell website. T6 is indeed full synthetic. T5 is the blend.

 

I don't know that I would really take up the whole synthetic argument with Great Danes as he seems to be well versed in true synthetic oil production. I can't see anywhere on Shell's website that it states T6 is made from Group IV stock.

I always thought Rotella was a great product until I saw how 6.0 injectors react differently to it. Call it what you will, but there is definitely something not right about their product in general. I would prefer to stick with Valvoline Premium Blue Extreme, Mobil 1, or Amsoil for synthetic diesel oil.

Perhaps an email to Shell is in order to clarify the composition of their T6 product.

 

Thanks for the compliment. I just recently became well versed on the issue as I did all the research I possibly could and came to the conclusion that the North American market has vastly different oils than Europe and that we only have 2 or 3 true (Group IV) synthetic oils to choose from. Group III+ is somewhat further refined than regular Group III and as a result of a legal loophole, manufacturers can blend this with minimal amounts of Group IV stock and refer to this as full synthetic, when obviously it is not. Europe has different guidelines and there are more true synthetics available, even from manufacturers that sell product here in North America.

Shell (or any other producer for that matter) will not divulge this info as they deem it to be proprietary.

 

I have heard that Shell is a group III and mobil 1 is a group IV, I personally use the mobil 1 . I have for years in my 6.0, and will be using in my 6.4.

Check out bitog (bob is the oil guy) website lots of good reading there.

 

Danes & Deere - This is really interesting information. I think it's worthwhile to understand it more. I have always used Mobile 1 on all my previous vehicles and understood it to be a full synthetic oil but I also bought the marketing data that says Rotella T6 is also. Sure would appreciate some clarity on this matter.

 

Agreed. BITOG is a great site with lots of info.

Mobil 1 and AMSOIL are the 2 major full synthetic (Group IV) producers available in North America... Castrol sells a product here as well, but it is actually made in Germany and I don't believe it is recommended for our trucks (I may be wrong on that one).

As Epic mentioned the T6 data is a marketing thing and technically speaking this is not a true synthetic oil, although I am sure it is a fine oil and obviously serves many people very well.

For those people wanting a true Group IV synthetic oil, Mobil 1 or AMSOIL are about the only two options readily available.

 

You guys kind of went over my head concerning oil. I've always let Ford service my past trucks, with what I'm not sure and it really hasn't concerned me, so long as the truck performed good. But, I've never paid this much for a truck and I want the BEST that will keep this dude running for years to come. Apparently my dealer is telling me a little fib or their using something other than Motorcraft. Gee, how can something so simple be so complicated. Thanks guys for the info.