Lexus said GX 550 gets 17 MPG, but it dosent make sense. The LX 600 uses same engine with higher 409 HP gets 17/22, 19 MPG combined, the GX has detuned 349HP, but only gets 17 MPG? Anyone know whats going on?

 

The GX even though boxy, is also lighter so I agree with you. I was thinking it's combined mileage would be at least 20-21 mpg, even though the engine is detuned.

 

Didn’t they say production vehicle is subject to change?
I think 19MPG combine on the LX600 is a little stretch.

 

Exactly it's not in production yet. Calm down people.

 

my thoughts exactly.

 

https://www.lexus.com/newGX scroll all the way down to "press release". It's kinda official if you ask me. On Canadian lexus.ca website it also posted 13.8L/100km which is 17MPG. Anyway, thanks for your reply. I hope it's better than 17MPG

 

Detuning the engine doesn't make it more efficient. Thats not how it works. The torque curves on the two motors are 100% artificially set within the PCM and the HP difference is a matter of changing a few numbers in the tuning. The only time the GX engine would use less fuel is if both are at WOT and the LX is using all of that 409 hp while the GX is limited to 349. The engines are physically the same and will operate the same when producing the same power/torque.

Take a look at the Tundra. They don't differentiate between the detuned SR trim with 358hp/406 tq and the SR5 and higher trims with 389hp/479tq because its all in the tuning. If both engines are producing 200 ft-lbs or torque at 2000 rpm, they will both be operating exactly the same and using the same amount of fuel.

EPA tests arn't running the trucks at WOT.

 

Also I wonder if the 17 mpg combined is for the Overtrail with 33" all terrains and they are just broadly applying the same MPG across the board.

 

that’s definitely a possibility.

 

New to Lexus, so excuse me for ignorance. If the mech is the same on the LX / GX, is it possible to load the LX fuel/air map into the GX and safely drive around with 409 hp?

 

One of the reviewers on YT(Toyota Jeff), flipped through the handouts they gave the reviewers in Tucson in preparation for the Feb 1 driving reveals. All of the spec sheets said 15/21/17 for MPG, so average fuel economy is 17 MPG regardless of trim.

 

5 degrees better approach than previous GX - this hurts MPG
smaller turbos so they spool faster for off-road response - this hurts MPG.

It's clear they balanced compromises well to still obtain better MPG than previous GX.

 

Real world MPG won't be any better.

That's sure a healthy torque figure though, for sure.

 

I’ve never averaged under 18mpg on my 2022 GX at 1900ft ASL event though I have a full set of BudBuilt 3/16” stainless skid plates and OEM size Falken Rubitrek’s installed.

Most of the time I’m in the 20-21mpg range.

 

There might be a 3.5 V6 Hybrid in the mix.