15-w40 for fuel?
 

i know where an endless supply of free 15w-40 engine oil is. question is can i burn it for fuel? should i heat it up before it goes into the motor? start on diesel, run on oil? mix it 50/50 and go. forget it and just change oil really often?

Just change oil really often.

worth it to heat your shop with it.

i heat my shop with used motor oil. lol, got plenty of that on hand. cant get rid of it all winter

Waste motor oil
 

Yes you can use it as fuel. Start at a lower mix about 20% move up slow with each tank and see how much your truck likes. I was burning 80% with no problems on 6.4 2008. I also had to do the SCT DP delete so as not to clog it. Now when outside air temps. are getting colder I have to mix 50%. I have been doing it for 20K miles.
Now as for lubercation add 2 stoke oil. I use 2 cups for 10gal and acidtone to help with the burn.

how much acitone per 10 gal? and if you get too much does it become a problem with cold temps. it never gets below freezing here so im probly okay

how much acitone per 10 gal? and if you get too much does it become a problem with cold temps. it never gets below freezing here so im probly okay and would there be any difference between using new motor oil and used motor oil. because i can get all the fresh motor oil i want.

waste motor oil
 

It has beed said that 1 to 3 OZ for 10 gals is good but no more. If you put too much in your tank than your MPG will start to fall off. Also I forgot to say that filtering is important, I filter to 5 microns and you can get new oil that will help going though the filter faster. I mix mine up in a 30 gal drum than add the diesel, 2 stroke oil and acidtone. From there it gets pump to the truck.