I am running a updated U7170 Diablo and since tune upgrade I have great power but have lost 5mpg.Truck passes diagnostic tests on certified computer but do not know where the mpg's went to?Question:Are the DP-Tuners hard to use?I do not switch tunes much,I like to stick it in one that I can drive/pull with and have power/mpg's around 19mpg.Bad part,have $350 tied up in this programmer!Looks like several of ya'll run them?

2002 F-350 4x4 215k 4'' exhaust,K&N cai.Diablo Predator U7170,Texas

 

What are you using to track mileage?

 

I use the gals divided by miles.Just checked it again this morning after filling up and it was 13.I guess I should have never sent my Diablo in for updates.Tell me what you think about the wicked wheels.Have one on your turbo?

 

WW changes the compressor map and makes the surge much better. It is a little less efficient than the stock wheel but when you mod these trucks the surge created by the stock wheel can ultimately damage the turbo bearings. The mileage drop off could be partly because of winter blend as well.

 

Oh yeah, the DP tuner is very easy to use and you can switch tunes on the fly, very easy.

 

I have been thinking about changing the stock wheel to a WW.Do you know a estimate on the labor cost.I seen where some have done it themselves.I do alot of industrial/tractor mech work but this seemed a little tricky.
Did not think of the winter.My wifes 07 Dodge has not dropped and she has the Dr.Performance 2021 in hers.....Thanks

 

Have not made my mind up about spending the extra money on another tuner.Have $350 tied up in the one I have.

 

That's good that you aren't using the overhead display to track mileage, because it is not even remotely accurate after you add a chip or tuner.

However, even when using the miles/gallons method, there is still a problem with the Superduty. Inside the tank there is a vent tube that protrudes down from the top of the tank. This tube causes foaming issues when filling up. The problem is that you don't know if you are filling up to the same spot every time. When there is foam present, the pump will automatically shut off once the foam reaches the filler neck. However, there may still be room in the tank for another 3-8 gallons of diesel. A 3-8 gallon spread can affect your mileage calculations considerably.

The only way to truely track mileage in a SD is to drop the tank and cut off the vent tube inside the tank. This allows you to completely fill the tank with fuel, and not foam. If you are able to fill up to the filler neck, then you know you are filling up to the same exact spot every time, and your fuel mileage calculations become much more accurate.

On another note, the others have mentioned winter blend fuel. This does affect the Powerstroke considerably, so be aware that it's normal to drop a few MPG's during the winter months.

Last, don't expect 19 mpg's on a 4x4. Unless you drive like a super slow old grandpa, it's rarely going to happen.

 

You could sell the Diablo to finance your next one. If you're decently mechanically inclined (and it sounds like you are), you'll have no problems swapping the wheels. I did mine on the truck, but knowing how easy it is to pull the turbo (I have since swapped in a van turbo), I'd just do that. Get a set of pedestal O-rings and go for it. Might also plan to gut the EBPV while you're in there. It's a good mod too, and also fairly easy.

 

Pocket..I have read alot of your replies and sounds like you are very noleable on the PS's.Thanks
Thanks Izzy351..Maybe I can e-mail and you explain the procedure on the tubo.I see you are in the Metroplex,I am in Glen Rose.brazosriverat@hotmail.com

 

That and the from what I have heard, the pumps only have to be within 10% of accurate. 20 gals on the pump may only be 18 in your truck, but it could be 22gals, but for some reason, I doubt it errs in our direction often.

 

I cann't see a pump being 10% off. I think its 1% because the pumps have to be tested and calibrated every few months. At least I think thats what I read on the sticker on the pump.

 

You might be right, don't even recall who told me that.