Ford 6.7L Diesel - Oil Viscosity Choice

[seahunter]

My owner's manual states one definition of severe towing is "towing a trailer over 1,000 miles". I don't push the truck really, but do most of you go with the severe duty usage and use the SAE 5W-40? I ask because I went in for my first oil change today at the Ford dealership, and they looked at me like I had three heads. They didn't even have enough oil in stock to do the service so I have to go back tomorrow! I thought this was rather strange. Maybe they just don't get a lot of pickups through there, but it is a pretty big dealership. Just wondering what weight folks are using.

Greg

[Tom S.]

I use Mobil Turbo Truck Synthetic in my Duramax, which is 5W-40. It's expensive at $5 to $6 a quart, but I do my own oil changes so that lowers the end cost. I'm a HUGE fan of synthetic oils.

[ols1932]

5W-40 here and my truck is 18 years old!

Orv

[seahunter]

Thanks for the input Tom and Orv!

[mlh]

Mobil Delvic 1 5 w 40.
Lynwood

[1retired06]

I use Rotella T6 5W40. Autoway Ford in St Petersburg treated me the same way, insisting that was the wrong oil for the diesel. I was supposed to get the first oil change for free when I bought my truck there, but they refused to use 5W40.

[seahunter]

quote:Originally posted by 1retired06

I use Rotella T6 5W40. Autoway Ford in St Petersburg treated me the same way, insisting that was the wrong oil for the diesel. I was supposed to get the first oil change for free when I bought my truck there, but they refused to use 5W40.

Wow, I feel pretty good then. They didn't fight me on it, and not only that, he said since it was synthetic it would normally be about $70 more but since it is my first complimentary oil change, they are actually going to use the 5W40 at no extra charge.

[Flymutt]

Interesting...I've been using Rotella T 15W40 on my 05 Duramax. According to the manual, this weight is "preferred" in temps above 0 degrees F (I never drive in weather below 0)

[Art-n-Marge]

I think one must understand the spirit of a recommendation. I would be more concerned towing a trailer 200 miles a day if hills were involved compared to 1000 miles on just flat land. It's about how much you make your engine work (higher RPMs and heavy loads) and how often.

If you use Dino oil (which I do), my book says 15w-40w, but change it every 5,000 miles otherwise it's every 7,500 miles. I have never seen dino oil less than 15w-40w. Besides towing I carry loads all the time and rather than wonder when the truck is working hard, I stick to the severe duty schedule.

I don't have the courage to change to Synthetic oil which is typically designated as 5w-40w. This may where the confusion is created on the oil weight designations.

I haven't had any issues, but I don't live in deep freeze areas and only have 93,250 miles on my truck after 7 years (13,300 miles per year). I do live in high temps especially in summer and have towed or carried loads in heat and hills which is why I change oil every 5,000 miles.

I do know someone who changes their oil every 3,000 but he works at a Ford dealer and has a 2 mile commute to work. I still think he's over doing it and I also think he needs to find a longer way home since I don't believe his oil ever gets warmed up and I don't think changing it more frequently will help as much as getting more miles on the commute to warm up the engine oil.

[Hooker]

The manual for my 8.9L Cummins says to change the oil every 20k, 500 hours or one year, whichever comes first. It seems most use dino 15w40 (I use Rotella) since we don't go anywhere near 20k/500 hours...and it takes 28 quarts.

[seahunter]

quote:Originally posted by ols1932

5W-40 here and my truck is 18 years old!

Orv

I can only hope mine lasts as long!

[seahunter]

quote:Originally posted by Flymutt

Interesting...I've been using Rotella T 15W40 on my 05 Duramax. According to the manual, this weight is "preferred" in temps above 0 degrees F (I never drive in weather below 0)

Yeah, I don't get too low a temps usually in our area so I was wondering why the 5W40 is preferred. I'm thinking the lower viscosity just lets it get up and into the system a little quicker so you've got lubrication faster??

[seahunter]

quote:Originally posted by Art-n-Marge

I think one must understand the spirit of a recommendation. I would be more concerned towing a trailer 200 miles a day if hills were involved compared to 1000 miles on just flat land. It's about how much you make your engine work (higher RPMs and heavy loads) and how often.

If you use Dino oil (which I do), my book says 15w-40w, but change it every 5,000 miles otherwise it's every 7,500 miles. I have never seen dino oil less than 15w-40w. Besides towing I carry loads all the time and rather than wonder when the truck is working hard, I stick to the severe duty schedule.

I don't have the courage to change to Synthetic oil which is typically designated as 5w-40w. This may where the confusion is created on the oil weight designations.

I haven't had any issues, but I don't live in deep freeze areas and only have 93,250 miles on my truck after 7 years (13,300 miles per year). I do live in high temps especially in summer and have towed or carried loads in heat and hills which is why I change oil every 5,000 miles.

I do know someone who changes their oil every 3,000 but he works at a Ford dealer and has a 2 mile commute to work. I still think he's over doing it and I also think he needs to find a longer way home since I don't believe his oil ever gets warmed up and I don't think changing it more frequently will help as much as getting more miles on the commute to warm up the engine oil.

Good points Art. There really is a big difference in how you drive as to how often you may want to change it.

[seahunter]

quote:Originally posted by Hooker

The manual for my 8.9L Cummins says to change the oil every 20k, 500 hours or one year, whichever comes first. It seems most use dino 15w40 (I use Rotella) since we don't go anywhere near 20k/500 hours...and it takes 28 quarts.

Twenty-eight quarts! Ouch!

[Tom S.]

quote:Originally posted by Tom S.

Exactly. It has been said that most engine wear occurs during cold cranking, and by cold, they mean anytime the truck has set long enough to reach ambient temps, which could be -20 or +70 degrees Fahrenheit. A 5W oil, especially one made synthetically, flows better at all temps, but most notably at low temps where a regular 15w oil can turn to a tar like substance (figuratively speaking).