Probably just a difference in the additive package, but it could also be group III, rather than IV or V (I'm not sure which one is TWS), both being 100% synthetic. Group III oils, like Mobil1, Syntech, etc. have a dino base stock, but they're allowed to say they're 'fully synthetic', which is crap. But K&N also says their filters filter great, eat a pill and eat all you want without getting fat.... so I don't believe any marketing in this country
At any rate, if you decide to use it, I wouldn't leave it for more than 7,500 miles, plus I'd also get an oil analysis done to see what you find. I personally rather use the right oil while under warranty, but that's just me. I'm doing my own oil changes, and just did my annual (low mileage) one. Will all the horror stories I've heard, and only dealer in town being small, it's a small price to pay
. Take care.