The dual turbo design isn’t for added power. The small, fixed position, turbo drives the larger, variable geometry, turbo in a manner that eliminates the turbo lag. For thos that do not think they have turbo lag just wait until you drive a 6.4.
To clarify to 6.0 reliability troubles let me offer an abbreviated description based on complete hands on experience. The early 6.0’s were by far the most troubled. But let’s be clear here and seperate the engine from the engine management system. The mechanical enigne is and always was “bullit proof”. The failures early on came from poor choices in engine management. Fords diesels are built by International and International insisted on using a version of their Diamond Logic control system. It didn’t work. Over 23 PCM updates later and the 6.0 was starting to run as it should have. That is phase one of the 6.0 troubles.
Phase two wasn’t the fault of International or Ford. It was the EPA and the relaxation of the LSD (Low Sulfer Diesel) standard. The 6.0 was built to run on diesel with no more than 500 PPM sulfer. As the 6.0 was rolling off the line the EPA relaxed and the actual PPM varied but almost never came as low as the “allowed MAX” of 500. This caused all the turbo and EGR problems that people had reported. The additional soot created from the sulfer wreaked havoc on the VGT plate and solenoid as well as the EGR. Ford has service messages that detail how to properly disassemble and clean the turbo’s. Something that has never before been recomended by an manufacturer, the wholesale disassembly and cleaning of a turbo! However since about October the new fuel standards have again been in place and many areas have had the ULSD allowing people to run the 500 or 15 PPM (both numbers indicate the highest amount allowed) and the issue with stuck turbos and EGRs is all but gone.
When running as designed the 6.0 is an extremely potent engine. Neither the Cummins nor the Duramax (all in stock trim) will flog the 6.0. The drawback to the 6.0 is it is a relative fuel hog compared to the 7.3 and chipping the 6.0 doesn’t add MPG. The power chips make the 6.0 snort like crazy but also raise combustion chamber pressure so high that it won’t be long and a headgasket will blow. While some feel the 7.3 was the better engine they must have forgotten all the $500.00 injectors that have failed or the high pressure oil pumps that blew or the countless other little problems that everyone came to accept. In comparison to anything Dodge or GM offered in the early days of the 7.3 PSD these kind of problems were easily accepted.
As good as I think the 6.4 will be I’ll say now that the people that like to modify these trucks will be sadly dissapointed. Chips will be a thing of the past thanks to exhaust baffles and regeneration. All diesel engines will suffer from the growing pains of the same exact system as all three will be using it. Don’t know what I mean? Better study up! It is the very reason the trucks are going to take a 4-6K price hike.
I thought I had power with my 6.0 but this one feels like it has twice as much. Much different power band then the 6.0. It was like driving a gas truck, no turbo lag at all and super smooth. The redone interior is just about like the F150. And the 3D navigation was cool to 
I was almost tempeted to order one today. The only thing that was holding back was that I didn’t have an extra $45,000 around to buy one and I don’t think the wife would aprove 
I didn’t pay even close to that for an 06′ 4 door loaded lariet.
the 6.0 has more power.
