I've got a 2.8, and Rick has a chip on the way for me for it, but I have a problem. My local fueling center only has 90 instead of 91. I spoke with Rick briefly about it, and he doesnt really recommend the 2.8 with 90 (not at all really) but Torco did come up and it got left at that. (all of which were PM's, phone messages and such) So, would torco be something I should consider (1 bottle per tank?) where can I buy it, how much is it? I'm assuming I'd have to buy a whole bunch at a time since i drive the cobra every day....Should I just drop the 2.8 and go with a 3.10.....let me know what you think.