Why does the GX550 get worse MPG than the LX600?

[Buck]

The GX550 is rated at 15/21/17 MPG, with 349 HP. The LX600 is rated at 17/22/19 MPG, 409 HP. Both have the same 479 tq and 10 speed transmission. I suspect the LX is slightly heavier and enjoys the extra 60 HP. Thoughts?

 

[Cobalt650]

This-is a very interesting comparison!

 

[Gunner]

Good question. I wish I knew the answer.

 

[killy]

Gearing, off road tuning of engine, ground clearance can be a big one, GX might be less aerodynamic. Buts it’s a massive game or calculus with dozens of inputs that are difficult to resolve to one silver bullet.

Highway numbers are a rounding error away, so my bet is more on the low speed gearing and tires being more optimized for off road that is dragging things down.

It’s not some conspiracy, end of the day most of the things the GX is good at are contrary goals to good mileage.

I’m personally quite happy they focused on those attributes rather than the cynical game of designing cars to game magic EPA ratings that detract from the experience.

 

[95YotaPickup]

Gearing, off road tuning of engine, ground clearance can be a big one, GX might be less aerodynamic. Buts it’s a massive game or calculus with dozens of inputs that are difficult to resolve to one silver bullet.

Highway numbers are a rounding error away, so my bet is more on the low speed gearing and tires being more optimized for off road that is dragging things down.

It’s not some conspiracy, end of the day most of the things the GX is good at are contrary goals to good mileage.

I’m personally quite happy they focused on those attributes rather than the cynical game of designing cars to game magic EPA ratings that detract from the experience.

I couldn’t have said it better, it’s always a tug of war between efficiency on road vs capability/comfortability off-road , and the GX is more leaned toward the latter

 

[supersix]

I'm surprised there is not difference between the Overtrail GX and other models. I figured the off-road tires would eat up some fuel mileage.

 

[wessermgm]

I'm surprised there is not difference between the Overtrail GX and other models. I figured the off-road tires would eat up some fuel mileage.

The biggest difference is aerodynamics. The LX and the old GX are more aerodynamic than the brick shape of the GX 550. Just look at the windshield angles. The GX 550 is very vertical oriented for an auto windshield (very similar to my old Jeep Cherokee). This is why the extra weight of the LX doesn't keep it from having worse fuel economy as the GX 550. The design is sexy as hell, but there is a price to be paid.

 

[SethGX]

It's a simple calculation that is based on adding the tire size and the angle of the windshield multiplied by the inverse of the amount of awesomeness to get mpg estimates. I'm surprised it's not lower for the GX once you realize that.