I'd buy the one that's cheaper per oz which is usually the Techron, Seem Amazon and Walmart run them consistently at around $12-13 a bottle for the 32oz, use a half a bottle every few thousand miles or so. For the last several months the 12oz bottles were on sale for $5 and the 20oz bottles were on sale for $8 at pretty much every retailer but they appear to have went back up. Redline is like normally $12 for a 15oz bottle and sometimes you can get a 12pack for less than $100 but that's still like $8-9/bottle, the 32oz Techron seems like a better deal if you use half of it at a time, just don't buy it from the autoparts stores because it's like $17 a bottle there.