Perspective F-450 4x4 CC buyer: Is the 6.4 OK? Improved over the 6.0???

[Lone Ranger]

How does the fuel mileage compare? I was getting about 14-16 mpg out of my F-350 6.0 average.... How is the 6.4 running on fuel economy...

How about with the 430 gears, how much will that hurt me?

And what about general reliability? The 6.0 seemed to have a few emission control problems like the EGR Cooler, and head bolt and gasket problems, are those cured in the 6.4?

Anybody have 430 gears F-450 fuel figures for me???

Thank you..

[foursixtysix]

On my '08 450 I was getting about 11 mpg average on a tank of fuel, most of the time I saw high 9's and low 10's though.. I did a full delete, with 5 inch exhaust, kept the stock intake and I have been running the Spartan 210 tune and getting around 14 average..most of my driving is city/short distances though. As far as issues I haven't had any though my truck only has 14k miles.

[hammett88]

the 6.4 is proving to be a good engine.. the issues are far in between.. you have to remember how many are out there compared with the problems you may hear.. in my opinion my stock engine that can withstand 610 plus hp and still be reliable is prty bulletproof..still worried? just wait for the 6.7

[geabis]

6.4 is one of the most reliable power plant we've seen since the 7.3.

mileage is bad i got 8-10 and 12-13 highway for my first 3k then i put the spartan on and am seeing 13-15 and 16-18. all on the lie-o-meter (mine only lies about 1mpg. i quit hand calc about 1k ago bc its really consistent)

[Lone Ranger]

Thank you for that advice Hammett, but I need a big towing machine now, about the F-450 4x4 CC size... And the 6.7 will not have Australian Design Compliance until about 2011 some time...

That is why I considering this 6.4 F-450 now, and sell in 2011 if you guys get good fuel economy and can't kill the 6.7... I need one for next year, and that is why the query on reliability and fuel with 430 gears..

I need to know if I can afford one...

[geabis]

another thing i just remembered. with the 4.30s and 19.5 rims it has the same rear drive ratio as my 3.73 with the 16" rims. i looked at this before i bought mine. now the 4.88s would definatly be some deep gearing and dont think there would be anything you couldnt tow.

[Lone Ranger]

OK geabis,

Lets see if I get this..
The larger wheels equals bigger loads... OK, got that.......

And you are saying the turning radius of the tyre in relation to the gears, is the same ratio with 19.5s and 430 gears as with the 16s or 17s and 373 gears... Right? Ok, I would like to believe that, and if so then the following would be true (roughly):

That means that a F-250, an F-350, and an F-450 would all run about (100km) 62.5 Miles per hour at 2000 rpm.. ??? Hope, hope... Then they should get about the same fuel economy running empty.. Is that right? I mean obviously the F-350 and 450 have more drag with 6 wheels and more weight by a few hundred pounds, but if your theory is right they should run about the same RPM per speed and roughly the same fuel economy..

Make me a happy Man and tell me this is correct, OK?

[geabis]

Originally Posted by Lone Ranger

OK geabis,

Lets see if I get this..
The larger wheels equals bigger loads... OK, got that.......

And you are saying the turning radius of the tyre in relation to the gears, is the same ratio with 19.5s and 430 gears as with the 16s or 17s and 373 gears... Right? Ok, I would like to believe that, and if so then the following would be true (roughly):

That means that a F-250, an F-350, and an F-450 would all run about (100km) 62.5 Miles per hour at 2000 rpm.. ??? Hope, hope... Then they should get about the same fuel economy running empty.. Is that right? I mean obviously the F-350 and 450 have more drag with 6 wheels and more weight by a few hundred pounds, but if your theory is right they should run about the same RPM per speed and roughly the same fuel economy..

Make me a happy Man and tell me this is correct, OK?

i went from a 2006 3500 GMC that had 215r16s i do believe, they may have been 205r16s (cant remember what i had on it last) and the 450 has 225r70 19.5s and the distance traveled with one revolution of the drive shaft is approximately the same. if i am remembering correctly the gmc would of had a 4.2 ratio after normalizing. as far as mpg the GMC was at 14-16 mpg town and up to 19 (i had seen 20-21 but that was all flat land and no load) highway. were as the ford would give me 9mpg town when i bought it. after putting the spartan on it and getting rid of the dpf i get 13-16 around town and 15-18 highway. now this is a much larger truck 14500# GVW compared to 11300# GVW and the allison does have a higher 6th gear than the fords 5th.

you are comparing ford to ford and i haven't researched how their final drive ratios stack up (i couldn't drop down to a smaller truck and didn't want a GM MD chassis). but its fairly easy just find your circumference of the tire being run ( there are numerous calculators on the internet) and see how far you travel on on revolution of the drive shaft.

[po-po 5.0]

STock 6.0 vs stock 6.4: The 6.0's fuel economy is better, but everything else is better on the 6.4.

[geabis]

if i get some time tonight or sometime over the weekend. i'll sit down with the 2010 specs and calculate the differences on the rear end ratios and tire sizes for all the superdutys and try to put together some sort of comparison to make it easier to look at with a quick glance and base a decision of gas mileage vs weight and rear end ratio. i tink it will be useful for anyone weighing out a decision.