I am getting ready for my first oil change since I've been running bio. Just wondering what the benefits of 5-40 are instead of 15-40??

Thanks,

Thanks moneypitt

I would not put in 5-40. Viscosity will be too thin for a diesel.

5W-40 is fine for your truck year round. Better cold weather flow and starting.

I have had a couple of ford diesels. I just started making and using my own bio-diesel a few months ago. Started using it at about a b-90 mix, now that the weather is getting cold (in the teens at night), I am mixing it at about b-50. The truck I have now is an 06, and the oil is black every time I change it at about 5k intervals. My truck has 69k miles on it (yes i know that is a lot of miles for an 06). My last oil change was a few weeks ago, and the oil looked the same as always. I figure most of the milage between this change and the last were run on bio-diesel. Bio is a solvent, and it does clean everything from the fuel tank and up. But remember, your driving a diesel. My last truck never saw any bio-diesel. It was a 94 turbo diesel that had 100k on it when I bought it, and 205k when I sold it. I could change the oil in that one, drive it around the block, check the oil and it would be black as coal. Point being that it dosn't take long after an oil change for the oil to look black. I think when running bio its a good idea to keep an eye on your oil and change it at shorter intervals.

I've been running bio since new and oil gets dirty pretty quick and change at 5k

So I don't think its the bio but just that its a diesel . :-X22

Oh yea I run 15w40 Delco diesel

I'm glad I found this thread, and apologies to OP for hijacking, but felt it was better this way than ask the same question again.

At any rate, I recently bought a 1992 7.3 dump truck. It has 46.5K miles on it. I've been running B95ish since I bought it this summer but have only put about 500 miles on it. The oil wasn't due to be changed and was still at full with 2000 miles yet to go. When I checked it today it was BLACK and felt dirty so I immediately changed with 15-40 Rottela T. It was black again immediately - but now feels smooth and slick.

I've read in this thread it'd be a good idea to change again at 3-5K, but I'm alittle nervous. Anybody wanna give me a nice warm fuzzy feeling about this?

BTW - I also stopped using bio today and filled up with dino (my bio supplier doesn't have any winter additive). Maybe run up to 25% bio over the winter.

How many days from you last oil change did you change your oil. I change mine every 90 days or 4K miles.

Check out this link. http://www.practicingoilanalysis.com...up=OilAnalysis

Interesting reading. I don't know when the previous oil change was done, as it was done at the dealer before I bought the truck. I suspect spring time, but there's no way of knowing. I can also only speculate on the miles - the sticker said it was due 2000 miles from now. What do you figure the dealer used as an interval?

I had to buy a bigger drain pan because of the whopping 11 qt. capacity, and the fact it's my first diesel. I'm thinking I might have it tested - it should be OK pouring a sample out of the brand new container (right?).

No issue with the sample from the new drain pan. I have used Blackstone labs for oil anlysis. They are a sponsor on this site.