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Discussion Starter #1
So I haven't been on in a while, business has picked up considerably for me. But it seems like the consensus on the forum is to go with the Flashpaq. I have an 06 4.7L, and it appears that several have already used these on their XK's. I don't care about performance or more go-fast feel. I tow a 24ft travel trailer (which is probably on the close side to being at the XK's tow limit) and need more umph...yes, I said umph...I can usually only muster about 55 without sending the revs to 3500 or higher. I don't mind running them higher when needing to pass or get going, but for optimal fuel mileage, 2k rpm is about perfect. When towing, I try to keep it about 2500 rpm. I average about 13.5 everyday driving, when towing it drops to about 9 mpgs. Not too bad, I guess....so...point of this long post is to ask for some advice...anybody?
 

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I love the FlashPaq but I would gather information from those with the 4.7L since their experiences are going to be closer to yours.
 

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I can't comment on tuners, but you don't want to drop the rpm's too low when your are towing. You don't want to lug it. I would think you would want to stay at an rpm that will give max or close to max torque.

What weight is the trailer and contents? It's probably over your max. Occassional would probably be ok but on a regular basis or sustained trip, seems like it would damage engine/transmission. If you are going to do this, you might want to get a transmission temperature gauge and watch the heat.

Good luck.
 

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Although the trailer weight may be close to the Commanders maximum, I bet the frontal area is the real culprit.
That things gonna have drag aplenty above 55.
Your asking a lot out of only 287 cubic inches......especially if you want low RPM torque.
Can't happen, the lever (stroke) is too short.
Back in the day of only transmissions with a one to one high gear, 2800 to 3200 RPM operation was the norm and posed no threat to engine life.
Nothing has changed, they can run like that just like they used to.
On my own 97 Chevy which tows a 24 foot car hauler, which, when loaded weighs just over 9000 lbs. the manual says to tow in Drive, not Overdrive.
This is a one to one ratio, I operate at 2900 RPM at 65.....all day long if thats the trip.
It is only a four speed auto...4th is .70 overdrive.
Kind of interesting, you can see torque loss with lower RPM.
This has a cable throttle, so, when the cruise is on you can watch the pedal (not stare at LOL) be drawn down when approaching a hill or rise.
Well, if I'm running at 65 in Drive (third) showing 2900 RPM and then slip it into Overdrive,
the RPM's drop to about 2100 and the gas pedal is pulled almost to the floor....what happened, eh?
Well a 350 V-8 really isn't making good torque numbers till around 2500RPM and above.
By taking away its mechanical advantage of gearing and slowing the engine down, reducing torque, I am watching it try to replace torque with....fuel...throttle position...its doing anything it can to keep from downshifting....and it succeeds.
But the engineers were right, it is much happier towing in Drive and to prove it, it returns 13.5 MPG on flat ground, still day conditions.
A big block or diesel will accelerate faster, but the fuel consumption will be almost the same between the three.

My thoughts, experience,
Rob

P.S.
What I am trying to relay is, the odds of a reprogrammer giving any benifit are highly unlikely.
It cannot increase torque to any noticable degree....maybe a few ft.lbs. but nothing that you would consider an improvement under your current operating parameters.
 

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I also love the Flashpaq tuner after installing it last week. Even with my 75 series tires and 2 in RC lift, I experienced 12.5 MPG pulling a moderately sized duck boat this past weekend in the 87 Performance setting. I haven't tried the towing setting, but I had plenty of power, and didn't have to re-tune when I got done. Definately pull the trigger on the tuner...best mod I have for immediate impact for the money. Disclaimer: My results were with the 5.7L engine, so you may not get that good depending on what you are pulling.

-Tom
 

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Discussion Starter #6
Sounds like the tuner may not help the towing much then. But it may help with fuel mileage around town. I really want to find a Hemi to trade up to, or pull the trigger on a big boy truck (diesel), as the girlfriend and I will be upgrading to a larger camper in the future as well.
Guess it doesnt hurt to spend the money on it now, since I will be keeping the truck for the next year or two at least.
 
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