Yeah, you can put whatever you want in it, though factory fill is never a bad option. I figure if the engine was designed around it to some degree that it can't be a bad idea to use. Doesn't mean there isn't better stuff out there, but it makes it easy to deal with. There have been some studies done that say overall it doesn't really matter what oil you use in anything, as long as you regularly change it. Weight probably matters more than brand.
Most Dealers have switched over to the Pennzoil Ultra Platinum Synthetic which is made out of Natural Gas. SRT Engineers and Shell/Pennzoil got together and worked on a new formulation for the Viper , as they did not ( at the time) have a 0-40 product. Do believe it is still the only fully Synthetic made from Natural Gas though other Petroleum Corporations were looking into it or were going to buy through Shell. All that being said, Mobil 1 is very good also , and of course a bit easier to find. Either choice would be a good one in my personal opinion.
Thanks to all for the feedback.....decided to go with the Mobil 1 0W-40.
I'm a first time Viper owner and learning more about it all the time..... I Just removed and replaced the clutch fluid using the ranger method.....I don't think it had been changed since new....The next thing I need to figure out is how to change the front & rear axle fluid.....hopefully I can find a "how to" video on Youtube!
The diff fluid is pretty easy to change since there are effectively drain plugs on the axle compared to a lot of cars. I believe they are actually plugs for where an oil cooler would normally attach, but they are on the bottom of the case so they work great as a drain plug. Getting fluid back in is the harder part if you don't have a pump. Hard to get a bottle to run downhill in the limited space back there.