looking at a 09 superduty 6.4L powerstroke

[Soundguy]

Actually Soundguy, my 06 6.0L F-350 SRW 4x4 will do high 23's on the highway. I drive by the tach and at 1,900 rpm, the sweet spot for the 6L from everything I have read, is where it does the best. I do have it chipped, 4" exhaust, and a different intake. My 04 F-250 4x4 is equipped the same but does about 1 mpg less. It has smaller tires so I think thats where the difference is. My 05 Dmax I had for a short time would do 20mpg at about 60mph with no mods.

Chris

what rear end does it has.. my f250 is a 3.73

best I have ever goten is 19 not towing and driven 'mildly' and 17 towing a 7k trailer unloaded, road miles.. etc.. anything else.. like laoded.. 13-14.. etc..

soundguy

 

[Dmace]

Although I am going with Ford for my next truck, just because of the no bailout stance they took.

Think again! Ford took plenty of tax payer money but it was hidden as EPA incentives instead of a "bail out"...

 

[Diamondpilot]

what rear end does it has.. my f250 is a 3.73

best I have ever goten is 19 not towing and driven 'mildly' and 17 towing a 7k trailer unloaded, road miles.. etc.. anything else.. like laoded.. 13-14.. etc..

soundguy

3.73 gears. All the F-250's and SRW F-350 with the 6L Powerstroke had that gear only..

If you 04 F-250 has 16" wheels like mine does you are right on track. With the mods mine does 22-23mpg at best. 19mpg is honest for a stock truck.

Chris

 

[Soundguy]

wonder what it would take to get my 450 to do that..

3.73 gears. All the F-250's and SRW F-350 with the 6L Powerstroke had that gear only..

If you 04 F-250 has 16" wheels like mine does you are right on track. With the mods mine does 22-23mpg at best. 19mpg is honest for a stock truck.

Chris

 

[Diamondpilot]

wonder what it would take to get my 450 to do that..

Not possible and keep the ability your big dog has. It is what it is, a pulling machine. :licking:

What I really want to see and have been waiting on for years is a tranny system that is computer controlled with a 6-8 speed auto backed up with a computer controlled high low rear end. Something like a final drive ratio of 6.50 and 3.00 That mated with a diesel engine should yield 30 mpg day in and day out on the highway unloaded and still be able to pull loads of 25,000# with no effort.

Years ago Gear Vendors made something like that for 2 wheel drive trucks that were popular in Dodge and older GM diesels. It would only fit on long bed trucks and mounted in place of the carrier bearing and gave you 2 speed ranges, much like a transfer case, to aid in pulling big loads. It was aftermarket and popular with the 454 big block guys and early Cummins trucks pulling 5th wheel campers. I have not seen one in years.

Chris

 

[JESSE1]

There's a posting on another forum about a few owners that installed the Gear Vendors on F-450 trucks. One truck had 4.88 gears and with the GV engaged it dropped his RPM's to 2000 at 70 mph. These were installed on 4x4 F-450 pickups. You'd have to drive a lot of miles to get a return on your investment.

 

[Soundguy]

interesting.

I remember a flatbed truck we had at work with split gears. had a solenoid in the rear end somewhere and a lil switch ont he shifter you pulled to go swap ranges.

would be a neat thing for a modern truck .. like a 'over drive type setup.. ie.. when at a stable speed, it could engage and drop rpms.. using the auto trans it could do it pretty smoothly without a lurch...

soundguy

Not possible and keep the ability your big dog has. It is what it is, a pulling machine. :licking:

What I really want to see and have been waiting on for years is a tranny system that is computer controlled with a 6-8 speed auto backed up with a computer controlled high low rear end. Something like a final drive ratio of 6.50 and 3.00 That mated with a diesel engine should yield 30 mpg day in and day out on the highway unloaded and still be able to pull loads of 25,000# with no effort.

Years ago Gear Vendors made something like that for 2 wheel drive trucks that were popular in Dodge and older GM diesels. It would only fit on long bed trucks and mounted in place of the carrier bearing and gave you 2 speed ranges, much like a transfer case, to aid in pulling big loads. It was aftermarket and popular with the 454 big block guys and early Cummins trucks pulling 5th wheel campers. I have not seen one in years.

Chris

 

[Soundguy]

Not possible and keep the ability your big dog has. It is what it is, a pulling machine. :licking:

Chris

yep.. I figured it would be a pipe dream.. she's good for what she does. I just plan on running her at 67-70mph max to keep her fuel economy at 8-9 mpg when loaded... as it goes into the toilet at 75mph ( 5 mpg or so.. :licking: )



soundguy

 

[JESSE1]

interesting.

I remember a flatbed truck we had at work with split gears. had a solenoid in the rear end somewhere and a lil switch ont he shifter you pulled to go swap ranges.

would be a neat thing for a modern truck .. like a 'over drive type setup.. ie.. when at a stable speed, it could engage and drop rpms.. using the auto trans it could do it pretty smoothly without a lurch...

soundguy

Two speed rear axles were very common in medium duty trucks. The very first ones were manual shifted, then vacuum shifted and finally electric. Seems like they're not being used now in favor of more transmission speeds. Used to drive Internationals, Fords and Chevys with 5 speed trans and 2 speed rear axles. Now it's more common to just have either a 6 or 7 speed trans and single speed rear axle.

Years ago you could get a Columbia rear end for cars. It was a two speed rear axle that you engaged when you were in high gear.

 

[Soundguy]

yep.. this would have been on an old chevy flatbed..

soundguy