I have used Lucas Fuel treatment for 4 years (and here goes the comments)
I mix 10 oz. lucas fuel treatment with 22oz. diesel kleen in a bottle and then add about 1/3 oz-1/4 oz per gallon of diesel,of my mix.
I have done this for over 3 years with no issues,and happy with what I do.
Actually Lucas is the only one I have found that has no kerosine,solvents or achol. which is not good for these new engines.
Diesel Kleen has a solvent,but they claim the type they use it is not harmful to the emissions and is safe for the new engines but use it.
I also use Lucas oil stablizer but only about 8-10 oz with the 10 quart oil change on my LMM.
With my Ford 6.0(sold) I put in 16 Oz. OIl stablizer with 14 1/2 quarts of oil and noticed the engine was not as clattery and smoother when using the oil stablizer.
2007.5 GMC Sierra 3500 BLACK SRW C.C. 4X4 LMM/Allison,long bed,Loaded,Westach EGT/Boost pass side, Edge Insight CTS EGT driverside, DIY stock airbox mod, aFe proguard 7 OEM airfilter. Back-up sensors + Back-up camera tied into the navagation screen, Redi Lift leveling kit, Cognito UCA's, Pitman Idler arm support, AMP Power steps, Firestone Air bags with controller in cab.