Got a buddy that just bought a '08 F250. I came across this thread on a Powerstroke forum and wanted to know what you guys think. I would think that a new 6.4 with a six speed auto would outrun a 5.9 / 48RE, but that's not what this guy seems to think.
http://forums.thedieselstop.com/ubbt...=0#Post3394332

 

I don't know about a race but was just talking to a new f450 owner at discount tires, with his 6.4 towing a six horse trailer tucson to flagstaff he got a whooping 4.5MPG bone stock.

 

The quickest quarter mile I have ever seen a 6.4 turn was something like a 16.3. It was a crew cab long bed single rear wheel. Most of his runs were in the mid 16's. Some guys have claimed they are fast, but those that know better have said they are not as fast as you think they would be. There's some guy on youtube saying he was beating dodges bad enough with his 6.0 and now he's beating them worse with his 6.4. I think he needs to race trucks that are actually running, not parked.
From what I have seen, I doubt that the 6.4 stock is faster than a stock 5.9, but it may be close.