Why does my 02 get better mileage than my 06?

[tmds3]

I have an 02 with 94000 miles on it and an 06 with 34000 miles. We have taken a trip to Colorado in both vehicles, same route taken, same time of year, everything the same except for the vehicles. On the 02 we averaged 22 mpg but the 06 we only averaged 18 mpg. When we take trips everything is done before we go,oil,air filter,gas filter if needed, air pressure and alignment.

Any ideas or thoughts.

 

[ExPlOrErImPoRtS]

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[EasyRhino]

I have an 02 with 94000 miles on it and an 06 with 34000 miles. We have taken a trip to Colorado in both vehicles, same route taken, same time of year, everything the same except for the vehicles. On the 02 we averaged 22 mpg but the 06 we only averaged 18 mpg. When we take trips everything is done before we go,oil,air filter,gas filter if needed, air pressure and alignment.

Any ideas or thoughts.

Which engines, transmissions, rear end gear ratios, size of tires (and whether or not same as OEM), and whether 2WD, AWD, or 4WD?

 

[tmds3]

the 02 is the 4.6 flex, the 06 is the 4.6 regular, both 2wd. everything is stock on both vehicles, not sure of tranny or rearend gears

 

[tmds3]

Any ideas?

 

[EasyRhino]

Only thing that quickly comes to mind, assuming all others items are equal (tire pressures, alignment, weight carried, etc), is that the newer one might have a lower rear end gear ratio. For example, the towing package on my 02 gives 3.73 rear gears and the non-towing package 02 I seem to recall has 3.27 rear gears.

Two ways to check this: look at the VIN tag on the door frame, where there will be a code for the rear gears (I think it is a letter). The other is to compare the engine RPMs at the same speed - if the 06 engine is turning faster at the same speed as the 02, that could well be your answer.