Hey everyone, not sure if this has been discussed before, I couldnt find anything about it in search. I've got an '04 f350 with the 6.0 in it. been running conventional 15w-40 Delo 400 in it. I run mobil 1 full synthetics in all of my other vehicles and thinking about putting it in the 6.0. I've found that mobil 1 makes a 5w-40 synthetic for turbo diesel but not a 15w-40. I'm just wondering if anyone has used this. I cant find it in stores locally but it may be worth it to buy online if i could push my oil changes to 8,000 miles or so with synthetic. Also does it matter that its 5w-40 instead of 15w-40? I will be in climates that range from about -15° to over 100°. Thanks.

 

Amazon.com: Mobil 1 44999 5W-40 Turbo Diesel Truck - 1 gallon, Case of 2: Automotive

$125.08 for 4 gallons. Anyone know of a better online vendor to get it from?

 

Mobil 1 is a GREAT oil !!!!!
I can find it at Walmart.

 

I agree - a great oil.

Ford has approved 5W40 for the temp range you posted.

 

Ya, i love the mobil 1 synthetic in the rest of my vehicles. I dont know why my walmart doesnt carry the 5w40. I looked closer at the picture of the 5w40 and it says on the bottle that its recommended for applications calling for 15w40. What interval would you guys suggest for synthetics in a diesel? Im thinking around 8-10k with the mobil oil filter. Does that sound about right? And if i went 10k between oil changes, I'm guessing i would need to do a chassis lube half way between oil changes haha.

 

Even with synthetic oil, you shouldn't go much past 5k miles. The oil gets sheared down to below a 30w in these engines in that amount of time.

 

Its pretty much well noted around these parts that no matter what oil you use you need to do oil changes at or around 5k miles. The engine apparently beats the oil up pretty bad.

 

Thanks for the input guys, I keep learning more and more about diesels everyday haha. I'm slowly moving out of my comfort zone of my ford 5.0L.


Cartmanea- You live in Corvallis huh? I just started at OSU this year. Do you know of any good places to wheel or shoot around here? I went up Mary's peak once, but there were some trees down on most of the trails and i didn't have my saw.

 

I haven't gone wheeling around here, usually do that back home in eastern Oregon. As far as shooting goes, you have to drive a ways to get to Alsea National Forest, there is also BLM land here and there around Mary's Peak. I've gotten tired of trying to find places to shoot guns and my bow and I'm going to join the Albany Rifle and Pistol Club this summer.

 

Don't feel bad. Around here Walmart doesn't sell it either, however, I'm not a fan of Walmart period, so it's no skin of my back.

 

This is why many people use Rotella-Syn 5W-40 motor oil.....

1) Lower cost - still get synthetic oil benefits.

2) Can afford to change it every 5,000 miles

BTW - per the opening posters post above, Mobil does not make an oil filter for the 6.0L motor.

The 6.0L motor shears all brands of oil down... so this is the reason for changing it at 5,000 miles. Expensive synthetic oil brands market their expensive synthetic oil brasnds by advocating extended oil drains... but all of us on this forum can show you via our oil analysis reports that all brands shear down.... so going past 5,000 miles is not advisable.

This is why I choose to use Rotella-Syn (less expensive)... so I get the benefits of synthetic, readily available at Walmart (along with Motorcraft oil filter) and I can afford to change it every 5,000 miles per the owner's manual.

Buy hey - nothing wrong with Mobil 1 if you got the money!!!

 

I guess i was mostly interested in the mobil 1 synthetic because of my brand loyalty to them. And if i could have gotten a couple thousand more miles between services that would have justified paying more. Thanks for the info guys. You saved me from makin a big mistake

 

Synthetics are still worth the extra cost. They stand up better to turbo temps and they do extend your OCI. With dino oils, I wouldn't go over 3500 miles.

 

For the sake of this thread... I used Motorcraft 15w-40 dino oil for the first 50,000 miles in my 2003 Excursion. After which, I switched to Rotella-Syn 5w-40.

My Blackstone oil analysis reports have always come back good and really showed no major improvement after switching.... but why did I switch?

I switched for the following reasons:
1) Better cold weather starting.

2) Better high heat protection (or the belief I was getting it).

3) I do not like to switch brands or grades.. so I use Syn 5w-40 year-round.

4) Synethic is more highly refined and cleaner than dino oils... so must be better for my motor and turbo bearings.

The key to the 6.0L is frequent oil and filter changes with OEM filters. I run a by-pass oil filter (which was given to me for free by Racor - OEM supplier to Int'l and Ford due to sending them my oil reports)... and the stock/OEM filter does such a great job and 5,000 mile intervals work well... that by-pass oil filtration does not really show any benefit.... maybe it would if I believed in extended oil drains, and yes the oil could go longer, but due to the shearing down of the oil by the 6.0L motor, I refuse to go past 5,000 miles.

Many of used dino 15w-40 oils and used OEM oil filters and changed every 5,000 miles with zero issues... so to each their own. My main reason for using synthetics was for winter/cold starting benefits.

 

I have read on here on many occasions the 5w40 is better cold starting in all temps and better for the injectors!