I think that I made this a more confusing question than it should have been ( from a price/value standpoint, at any rate) by failing to specify that I was referring to the "big" bottle of Techron at $9.88 which treats 20 Gallons vs. the "bitty bottle" of Techron at $6.88 (buy one, get one free at AA with rebate) which only treats 12 Gallons. I have an 18 Gallon gas tank, and would need the larger size. My wife's van takes 24.5 gallons. Thus the confusion (sorry, my bad). I presume that the $6.00 per bottle price for Techron at Wally World and $4.00 per bottle at O'Reilly's is for the bitty bottle. (We don't have O'Reilly's here in the Commonwealth - I think that people may believe that the stores are owned by Bill O'Reilly and won't let them open up. I am still amazed and grateful that we have Wal-Mart here in the People's Republic!!! Heck, where else can you buy a 5 galllon jug of Havoline, a loaf of bread, a DVD player, and a box of .22 rimfire all in the same store? I just LOVE this Country !!! [sniff])