Need some questions answered about the predator. Plz help.

[DJM]

In April of this year I inherited my Dads 2001 Chevrolet Silverado Ext cab, 2wd with a 4.8 V8. A few years ago my dad put a GM Performance Parts Cold Air Intake in it. I don't find that the truck gets that great a mileage on it. I average about 15.5 to 19.2 mpg. I have switched to synthetic oil and replaced the GM filter with an AEM washable filter.

I have been told that the next two things I can do are replace the exhaust and get a chip or programmer.

Research has led me to Diablosport which came highly recommended by a retailer but also by a friend of a friend who said that the predator is a good product. I believe the stock truck 4.8 Silverado was rated at 270hp and 285 ft/lb.

I am a total noob to the world of tuning, so please bear with me.

I am wondering if anyone who has the same engine could give me an idea of what kind of mpg increase and hp/torque increase they realized after doing a tune. I would most likely be looking at the 87 tune as gas prices are so darn high and I don't really want to switch to premium.

I also notice that you can switch transmission shift points with the predator? What advantage would this offer? Does changing the shift points affect the tow/haul mode?

If anyone can offer some advice I would most appreciate it.

On an unrelated note, any aftermarket performance exhaust kit recommendations? And any advantage to go to dual exhaust, or is it more for looks?

Thanks,

DJM