I have a 2002 F150 4.6l I installed the Superchip Microtuner in my truck after i bought it. My other truck is a 01 Expedition 4.6l and it has no microtuner, the question is why is the Expy truck so much faster then mine? I put the same Flowmasters and air intake in both trucks but the Expedition is ALOT faster and quicker off the start. Anyone have any ideas?

 

Gear ratios and tire size are 50% of the equation. What are they on each vehicle? You can read the axle code on your door sticker, there are many posts that will translate them for you.

 

Desperado is quite correct - also, vehicle weight, aero resistance (which is much higher in a pickup truck with the air hitting the tailgate) as well as normal production line variances from one vehicle to the next all play a role.

You cannot expect two different vehicles to perform identically or even similarly just because they seem to have the same engine & modifications - there are many differences even between seemingly identical vehicles that will cause differences in performance levels.

Also, seat of the pants comparisons mean nothing in this regard - what is required is properly controlled dyno testing including wideband A/F ratios to identify any difference in the actual amount of power getting to the ground in each vehicle and to compare the A/F's - along with proper timed acceleration runs on each vehicle, done at the same time, to really get an accurate comparison.

The bottom line is, each vehicle is going to do what it does - and if you have significant differences that just don't' seem right, then it's time to go over the vehicle with a fine-tooth comb from both a diagnostic and maintenance standpoint. Heck, a clogged fuel filter from just one tank of gas with some water in it ( which happens very often) can make a significant difference - there can be all kinds of reasons why one vehicle performs better than another.