I know this is an older thread, but most of the canola threads seem to have seen a last post about a year ago. That said, just thought I'd toss my two pennies out there about canola. I just finished milling (and by milling I mean cutting the 10 foot sections into quarters and quarter sawing a la Malloff) a 100' Sitka (about 32" at the butt) using straight canola in both my milling saws and the 346 I use for limbing. I clean the bars every day and check for wear, and so far there has been no difference between the Canola and the petro oil I was using. Well, there is a difference, actually...the bars are staying cooler, and it's a noticeable difference.
Since I'm not an engineer, I can only parrot what I read, and that is that the canola has a higher shear strength than the petro oil, so I presume that translates into a better ability to hang on around the nose. As for tacking agents in the petro oil, once the saws are good and warm, the standard bar oil seems to pour out just as fluidly as the canola does. I presume the additives adhere just as well when hot.
I've also read about concerns with oil going rancid, or gumming up the works after sitting, but I keep things clean I mill with a 281xp, 394xp, and 3120xp, and I pull the oilers and clean them up about once a month, so not worried. As for spoilage, I treat it like I do good olive oil in the kitchen: keep the lid on tight, and don't open a five gallon jug when one gallon will do. Even then, just transfer to airtight containers and keep out of the light. Oxidation is the enemy, so I don't let it oxidize.
Bottom line is that I have not seen a difference yet, except in what I am spraying a future vegetable garden, and a cooler bar. As so many here say, and with good reason, your mileage may vary, but it's working well for me. I've got several more spruce trees and a couple of red alders to go, so I'll keep posting updates if anyone is interested.