Dynamic

I am puzzles how MB was able to improve the new 2013 GL350 with 30 extra HP 55 extra pounds of torque and 5 mpg better milage on the highway in coparison to the 2012 model.

The vehicle size is the same, weights the same, uses the same 3.0 engine, same 7 speed transmission and has to comply with the same EPA standards yet accordding to fuelmileage.gov they show an increase in city highway MPG, horsepower and torque.

I have started my search with 2007 GL320 which shows 18/20/23 (city/combined/highway) then in 08 a small improvement 18/20/24 then in 09-10 with the addition of bluetech there was a drop to 17/19/23 in 11-12 a further drop to 17/19/21 plus lowered horsepower from 215 to 210 and then you see the new 2013 with 19/22/26 and 240hp 455 torque.

I understand why these numbers have dropped as the EPA made stricter requirements lowering HP and burning more fuel as a result. I can understand when a custom tuner makes such improvements with maping that does not pass emmissions but how did MB do all that on the same engine is beyond me.

dgiturbo

"...uses the same 3.0 engine..."
It's not the same engine. The block is made differently, using twin wire arc spraying coating. This involves cylinder wall coating technology that reduces internal friction in the engine, and reduces weight by about 9.5 lbs. AMG has been doing this since 05. The reduced friction is where most of the power is "recovered", and I am guessing they also tweaked the ECU a tad.

FastMoneyPlaya

I can tell you from real world experience, my 2011 GL350 gets much much better mileage than the EPA would suggest. I easily get 25+ mpg on the highway, and have even gotten as high as 28+ if I keep it in cruise control at 65mph.

Perhaps the new higher numbers are just closer to reality than what the old EPA numbers indicated.