B12 is stronger than MMO, Lucas or Seafoam.
I added a half a can to an '87 Ranger the other day. It had less than half a tank. I drove it for maybe 20-25mins and I was definitely impressed what it did to the truck. Accelerated better and felt like it needed since its been a neglected farm truck for the past several years.
These days with ethanol doing it's damage to everyone's engines stuff sold in the cans that some swear off and some use religiously DO WORK GREAT!
B12, Lucas UCL, MMO, And seafoam I must say are best of the best stuff you can buy and use in any engine to help clean it out a good bit.