わたしの　くるま　....Oops, using wrong language. Anyway, my truck gets around 12 city/highway, but one mans city/highway is not necessarily the same as the next. Mine is actually quite a bit of city driving with some 10-15 minute highway jaunts tossed in here and there. On the highway unloaded I can push 17 mpg if I stick to the speed limit (65) and treat the go pedal with some care getting there. This is better than I could do with my CC F250 Lariat 4x4 V10, and considering what a fat heavy weight pig my current truck is, not too bad I think.

My truck weighs in at around 9,400 lbs full of fuel and with me in it. I'm running factory sized rubber with 4.30 gears, bed cover, CAI, straight pipe exhaust, and a Spartan programmer set on the 210hp tow tune. I run this tune all the time, loaded or not. When I tow I'm pulling close to 17,000 lbs and I know conventional wisdom says don't tow heavily tuned, but my theory is don't tow heavily tuned....and driving like an idiot. I run the high tune and keep all my engine parameters such as engine temps, boost, tranny temp, etc within acceptable limits. As long as I stay within these limits I don't see what difference it makes if I'm tuned or not. I usually get between 8.5-9.5 mpg and have seen a high of 10.4 on one trip.

I bought my truck used with about 17,500 miles on it. By 21,000 it ate it's radiator, which was not unexpected based on the research I had done ahead of time. I have 36,000 on it now and no further radiator issues to date. I never had oil making issues but chose to delete/tune anyway and have no regrets. I have had no other engine issues at all, but did have the blend door issue, which again was not unexpected based on my research.

These engines are VERY easy to make power on, and from what I've read can handle quite a bit. Head gasket issues due to inadequate head bolts are not a problem. EGR/oil cooler problems are not the issue they were with the 6.0. Generally the tranny gives up the ghost on tuned 6.4s before anything else.

A Spartan tuner will add up to 350 (supposed) RWHP to a 6.4, and if you've got a stupid right foot, you CAN make bad things happen. To me that says more about a driver than the engine being flogged.


Keep in mind when reading "reports" online that very few owners will come online to sing praises of their vehicle. Good performance is expected when you buy a vehicle and generally doesn't warrant any comment when you get what you expected in the first place. On the other hand, almost everyone who has a problem is more than happy to come online and crow to the world about the "piece of crap fill-in-the-blank-engine" in whatever vehicle they just bought. Naturally this means that every engine in that category ever produced is also likely a piece of crap.

To date this is my most favorite vehicle I've ever owned, from BMWs to Broncos, and I don't regret the 6.4 one bit. It was strong enough to begin with, and tuned it's an absolute street beast.