A couple of notes. The oil in question is Mystik JT-8. I went looking for some infor on it and i figured it wasn't JP8 (jet fuel. . .diesel)
the state sheet i found for it list it's pour point as -27f (15wt40) and -22 (15wt50)
http://docs.mystiklubes.com/msds_pi/M20003.pdf
Shell Rotella T (15wt40) has a pour point of -33f
http://docs.google.com/viewer?a=v&q=cache:G8LHa7VJvp0J:www.shellusserver.com/products/pdf/RotellaTCI-4CI-4.pdf+shell+rotella+t+15w40+specs&hl=en&gl=us&pid=bl&srcid=ADGEESj-w5LsZa36GdNKSxz7fw45OZueVfGl1R-lMMkBkhJIFcP9X3RRNukpfmmERQhhEQWPU1B_herELFkWTFMEf3ToYnYFE73ET_WgjDFBfS67B1up8NTB2v6qXLwgMa2c637p-RmX&sig=AHIEtbSNYCqTUUOZNyHPvKXVh8RvJuaVGg&pli=1
I don't see a lot of differences in the oils that would lead me to use the JT-8, but no reason not to either. Now if they made a nice blended 5wt40 i mightb e tempted. Seems to me a 5wt40 would be a good call during the winter months, Any thoughts on that RDSL you know you stuff what you think?
shell rotella t6 5et40 -49f pour point
http://www-static.shell.com/static/can-en/downloads/shell_for_businesses/oils_lubricants/1-52.pdf
and then there is amsoil 15wt40 -44 as per their website.
It all makes my head hurt buti figure if i am paying this much attention to what oil i use then the truck is in good hands regardlesss of what i choose lol
There are a number of conflicting temperature specs floating around on that mystic . If you managed to actually find that on their website, it's probably the most recent, although someof the other listed figures are from group tests of a number ofdifferent oils andmight actually be more real world.
If VA as listed on your tag is where you spend most of your time, then there is no reason a 15w won't suffice year round.Most commercial rigs still use 15w-40 dino oil in all climates, and 20 years ago the rule used to be above 10 degf shut down below leave it running or plug in so the things will fire off for a heavy diesel, but even dino oils have dropped their pour points in recent years. If you ever get temps that are lower than the pour point of your oil and you don't have a place to plug in , then yes, you need to go with a lighter oil, that's the nutshell version. Otherwise you will be running dry, plain and simple.
It's no secret that there is no love lost between me and Rotella after loosing an engine to that stuff, but you show an affinity toward it and if that's what trips your trigger, make dang sure that you ALWAYS carry enough spare with you that you never have to run the risk of having to mix the stuff with anything else. Their oil has always done fine by itself, but they have a poor track record of rushing changes to market without thorough testing in regards to full market compatibility. I found out about this the hard way and it ruined a family vacation... not to mention a nice car ( trunk space was at a premium for the trip, no room to carry extra jugs of synthetic and it ate a bit of oil like all diesel cars do, so I switched it to rotella a while before the trip since I figured I could get that everywhere. ran on the stuff for a couple of months , but had to mix a qt of something else in Oklahoma in and in 500 miles the bearings and rings were gone, the stuff turned to the consistancy of water,didn't even have enough power to make it back up the hill out of Albequerque )
I found out later from a friend at a heavy truck shop that rotella was quietly paying for all the rebuilds on newer engines that were still under factory warranty under deals with the factories to keep things quiet, but for older engines, you were left holding the bag.
