The Supertech stuff for 7.88 US (blue jug) has a date on the reverse side at the bottom. The date I buy it is ALWAYS later than the date shown on the jug. I don't know if it's a mfg date or an expiration date. At any rate, I get ~700 mpg towing with anything I use. The ingredients show the same ratios as the pricier stuff. The spare I carry is usually the PEAK from Sam's/Walmart. If on the road and it will be consumed right away, will use the Supertech.
2016 XD 5.0 Cummins Pro4x Pearl White, Build date 4/2016, Conven & Util + Audio, Bumper Step Assist, Dark Chrome Step Rails (needed someplace to clean my boots before entering!), Front & Rear Splash Guards. 2004 Subaru Forester, 99.5 Powerstroke with mods, previously a 2011 Xterra Pro-4X - (a fine vehicle but was upsized by the XD)