@gfmoto
Emerson posted the part #'s for the Twin-Air that will work above in this thread.  As for the UNI the part # for this one is UP-6229AST.
I'll let NMK give you his thoughts on the better one.  I went with the UNI because it seems most of the guys here have used those when swapping out the paper filter.

[2015 Z Force 800 53/Trail EPS]

Both UniFilter and TwinAir's dual stage filters are pretty much the same as far as the grade of foam materials used. The TwinAir as a taper to it where the Uni doesn't but I don't think that really matters. I personally think both have not enough surface area for the 800s but they both do seem to work fine, just wish we could get a bigger or longer one with the same flange size. Like it to be an 8" instead of a 5 or 6. Think it will fit. I have not used the foam prefilter but do use the Outerwears prefilter on my second filter..which by the way is a dual stage Unifilter.

So in short, In my opinion, both are great filters and work very well. As long as the OE paper is gone, you are way better off.

Looks like I am gonna pick up a 2016 Z800EX EPS tomorrow.

I would like to install the UNI Filter option immediately. I found two part numbers commonly used. Would any of you all be so kind as to clarify which is the correct best fitting option for me please.

Uni 2-Stage Straight Pod Filter - 57mm I.D. x 152mm Length UP6229ST

or

Uni Air Filter 6" Two-Stage Pod Air Filter - 2-1/4"x6"/Angled Mount UP-6229AST

Thank You, I am quite nervous about dropping a big chunk of coin on a newer brand. I hope I am making the right choice....

[2015 Z Force 800 53/Trail EPS]

This one:

Uni Air Filter 6" Two-Stage Pod Air Filter - 2-1/4"x6"/Angled Mount UP-6229AST

OK gang it's time for my first oil/diff change after break in.  I've read the posts and looks like Shell Rotella 15w/40 would be a good fit for my area and machine.  Question is can I use that in the diffs as well or do I need to run something heavier?  Service manual says 15w/40 SG or 80w/90 GL. 
Let me hear your opinions.

BTW I ordered a UNI air filter as well and will get that installed next week once it gets here.

Thanks

I run 80w90 in mine during the winter with no issue.

I HIGHLY recommend using a hypoid gear lube.

the 15w40 is a great choice. It offers the best protection for these motors, especially since the internal bearings used arent the best.

If you can, go with the TwinAir + The Prefilter vs the Uni. I have had  much better luck in my personal one. The uni seem to get dirtier quick and requires more frequent services & cleanings.

Emersonsc what is the best air filter to use on a 2014 Terralander 800 (cforce 800) and do they come preoiled?

Twin-Air Filter 156052FR and the prefilter is  Twin-Air 156052DC. The air filter does not need to be oiled, but i recommend oiling the pre-filter.

I am unable to find 156052dc, Anyone have an idea where I can get one. I have looked on ebay and Amazon.

[2015 Z Force 800 53/Trail EPS]

I am unable to find 156052dc, Anyone have an idea where I can get one. I have looked on ebay and Amazon.

I never found one either. I would just get an outerwears prefilter. Just get the measurements and go to their site...get one larger then what you measure though..like at least an inch in all directions.

OK thanks I will look into it!

OK thanks I will look into it!

I have found a spot that sells the Dust cover for the Twin Air Filter.
http://motopartshouse.com/search/?view=search&search_terms=156052dc
Have one on Order