I too will be switching over to rotella 5w40 synth.. also got it at wallyworld. Right now I'm running Castrol 10w40 waiting for the next oil change, or the first snow (that sticks) before worrying too much. It's still in the 50s during the day here.
EC means energy conserving. This means that it has a friction modifier in it. Not good for transmissions or clutches. Will cause them to slip. If you do any research on the internet as to what kind of oil to use, you will find that Amsoil tests out the best in almost every catagory. I am switching to 0w-40 4 stroke Amsoil on my next oil change.
I'm still using up what's left of my stock of Castrol Act-Evo 10W40... but I just purchased a 16-gallon drum of the Polaris PS4 synthetic oil from my local Polaris dealer at cost, so I will be using that in everything from hereon out.
Anybody here who is local to Reno... there are three more of these 16-gallon drums available if anybody wants one. They cannot be shipped; they must be picked up (hence the part about being local to Reno). So if you want one, email me and I can put you in touch with the contact at the dealer. Cost is approximately $216 plus tax for the barrel. You will also want a $29 pump to go with it.
I think the honda stuff is just castoral with different label! LOL no, honestly I dont think that it matters!! I used to use honda oil and the mechanic stopped me one day and pulled me to the side...told me to go to wally world and get standard oil...that it was the same stuff?
When I walk in my dealer for waranty work,they know that I have used GN4 and Honda filters exclusively which eliminates any questions. Yes you can save a few dollars by using other oil but I don't want to risk it.