I pulled my xzillerator XZT about 1000 miles ago, as I'm nearing my 70k warranty and wanted to make sure everything was O.K. for the last 6000 miles.
At first I of course missed the extra power, but after driving it around like this I've noticed the truck runs much smoother.
I had a slight studder at the 1-2 shift when it was cold, and the studder was innermittent. I no longer have this.
I also noticed that my fuel mileage has increased about 2 miles. I don't know if it's because of the lesser power, and maybe I'm not conciensly getting on it. Or if my motor just likes the stock parameters better.
Anyway, I know the unit was advertised to increase fuel mileage, but I also never expected it to. However I didn't expect a large drop such as this.

 

My milage is the same when towing with the XZT. 10 mpg when towing 13k 5er.

Think about adding a Quad Commander. You get EGT, boost pressure, trans temp and more with the fuel pressure kit. You can also control the XZT from zero level ( stock) to level 3 by pushing a button. Use what ever level for good milage and then push the button for power.

 

I was having the same studder on the 1-2 shift. I was hoping it was just the xzt. I guess I'll send it back to quad and get it reflashed with the latest settings. Thanks for the post.

 

I didn't know that an updated flash was available. I also get a fuel pressure code every once and awhile, but it goes away after I start the truck a few times.
I was always worried about that studder but was O.K. with it after I realized it was a cause of the XZT.

 

I was thinking about getting one of these for my 03. You guys are making me just want to stay stock.

 

Mileage has always been better for me with my Quad Race in the "Off" position.

 

My mileage was always better in the OFF position too!!!

Actually, when I had the Quad STD on the truck my mileage was better than stock, made me think it was the boost fooling that was helping my mileage. I am a very conservative driver, the Quad was more for towing using the 1st two positions. I recently took the Quad off/out and sold it. Since it was better in the OFF position, boost fooling only, I just ordered a boost fooler to do the same thing. Now in the ON position NOT towing, my mileage was terrible, but that was my fault, or should say mine and the skinny pedal.

CD

 

You last two posters have a different box than the XZT. We were talking about the XZT.

 

I put mine in with the Commander and Smarty and have had no drop in MPG from before the install. I am getting about 15.5 MPG hand calculated with about a 50/50 around town and hwy driving.

I have the Smarty on #3 and the ZXT at #3 all the time. The extra power is nice and if there is no appreciable drop in MPG, why not use it?