I found an old bottle of Prestone FSC and called their tech support. The guy said that this product (which I assume would be a product similar to Techron) was made of petroleum distillates and shouldn't be used if it was several years old, so I took it to the local household hazardous waste.
It will all burn. Shake it for 15 seconds and pour it in. The companies just want more of your money... it's the same BS spiel as "motor oil only has a shelf life of two years..."
Last year I took some 32 year old Wynn's fuel system conditioner and poured it into my daily driver..... several ounces at a time on fresh fill ups. No issues.
I'd use the 14 yr old Techron as well, esp. with a lawn mower.
Zee09, mine was an example of two years as a slight exaggeration... you certainly like to leave out details since you actually STARTED the most recent thread about oil's shelf life:
Wow. That was the laugh I needed. Its late but that was fantastic. Go ahead and shake it,then run through a paint strainer, then use it to soak a barrel/bore to remove lead and copper. Or if its unopened then leave it alone and buy a fresh supply.