I'm getting around 14mpg, but it's only city driving, as there are very few highways here in Vancouver. I think for a 4.6L V8, it's giving very good mileage.

by computer, after fillup, ave mpg read 22.8.

believe it, i got nothing to gain by lying.

i left the LCD on eco and mpg mode, that helped a lot so you know how much you are depressing the gas pedal. try it out. There are plenty of hills on I-95, so that really had nothing to do with it. You shouldnt really be going past 70-80 mph in this. If your tire blows out, pray to god. Its not a sports car.

In the city, fyi, with stop and go, getting about 14 mpg.

The GX will get better mileage then my 4th gen V8 Limited 4Runner did. Supposedly the 460 has the best mileage in its class. That's pretty amazing considering it is a 5300 lbs vehicle.

Koz

Yes, stop and go is a killer but you really can't include stop and go traffic in the measure for city mileage. City mileage should be based on normal city driving where you do not exceed 40 mph and only stop for red lights, not rush hour traffic. Also the time of year makes a difference. The biggest effect on gas mileage you have control over is the gas petal and maintaining the proper air pressure in your tires. Using all synthetic fluids will also contribute (The 460 may already have all synthetics). As soon as I get mine, I will change the diffs to high quality synthetic gear oil. I'm an abscessed oil guy. I only use Amsoil products. Primarily, 0w-30 motor oil and 75-90 severe gear oil. From what I understand the transfer case uses “Gear Lubricant Special” (GLS), which is synthetic gear oil and there is no replacement fluid (only GM part # 12378557), so that will stay until Amsoil makes a replacement. I usually keep a vehicle many years and I always start with the best fluids.

Koz

Too bad we didn't get the 8 speed transmission like my LS 460. Our mileage would even be better...

The 6th gear in the 460 is substantially higher than 5th gear in the 470. Its also a little reluctant to downshift at highway speeds. The edmunds review noted this.

It helps the mileage, but for the first time ever, I'm starting to use the manual shifter feature in a car. I actually works pretty well with little chance of a screw-up. You just leave it at the"6" position, and if you want to get around someone at speeds above 65 or so, its very easy to just tap it down to five, which does the job nicely. If you're on a long upgrade, you might need to tap it to "4" to get the kick you want.

Do you notice any difference in how the GX 460 behaves between moving the shifter to 6 in sport mode or leaving it in D? In other words, do the shift points seem to change or does the transmission get 'stuck' in the wrong gear, especially when you slow or stop?

If I understand correctly, moving the shifter to 6 in sport mode tells the transmission to upshift all the way when the situation permits, e.g., the vehicle speed is high enough, the pressure on the gas pedal is low enough, the vehicle is not climbing a steep hill, etc. Presumably, slowing the vehicle, lifting off the gas, pressing the brake, descending a hill, etc. initiates an automatic downshift. If so, this would be a neat way to combine an automatic transmission with a simple manual shift ... with the minimum number of shift lever motions.
Regards,

SaniDel

As far as I can see, the manual mode in "6" behaves like the "D" mode. If you move the lever from D to the manual side at high speeds, it seems to default to the "4" gear, which is just a little lower than you really want if you're going 60+, IMO. I don't know why it doesn't stay in 6 as you shift over from D, but it seems as though it assume you want to downshift, by default, and puts you in "4".

Today on the streets I used manual to see if I could detect the manual upshifts when I moved the lever, and I was able to see the shift happen......until I went from 5 to 6. The 6th gear is so extremely high that the engine transmission has to be under a very light load before it will shift into it.

on highway going about 70-80 the rpm stayed consistently between 1500-1800 rpm. The 6th speed tranny and dual vvti i am sure has a lot to do with the gas mileage.

I did shift the gear over to manual mode on the highway once, and i think it did shift to 4th gear. RPM shot up so i quickly moved gear shift back to right side.

I take back one thing. Today I tried to duplicate the downshifting on a long highspeed downhill run when the brake is lightly applied. It appears that the GX does not do that in the manual/sport mode. I'll have to experiment a little more, but it seemed pretty clear that the downshift on braking was not there when the shift lever is in the other mode.

The best mileage we have gotten is 12MPG, normally we get 11 mpg, city driving here in south florida. Had a GX470, that got 14mpg? I thought the GX 460 would have done better. The EPA sticker was 1mpg beter than the X470. We use regular gas normally. I did try premuim gas, but it did not improve the MPG. Back on regular gas now.

I can confirm that. There is no automatic downshift in the 'S' mode ... it must be done manually.

I have adopted your suggestion that the 'S' mode is best for around-town driving. As you suggested, I leave the shifter in 6 and confirm that the transmission will upshift all the way. Other than manually forcing downshifts to 5, 4, 3, etc. on downhills and for slow-speed maneuvering, it operates as any automatic transmission.

What I 'sense' but can not confirm is that the shift points seem to be advanced, the transmission seems more responsive to throttle pressure and the GX 460 seems less 'clumsy'. Just the slightest increase of pressure on the gas pedal and the transmission downshifts ... a little more pressure and it does it again ... and quickly. Stand on it and it seems to downshift from 6 to ...well, there's no way to tell, but the GX 460 takes off like a rocket ... it's quite impressive for a vehicle that weighs almost three tons.

Starting from a stop with the shifter in 6 seems similarly more responsive. The engine revs higher between shifts although if you 'feather' the gas pedal it seems no different than the 'D' mode. Stand on it from a stop in 'S' and it redlines in all gears ... quite a ride!
Regards,

SaniDel

I just took a 410 mile drive over the PA turnpike and through NY into New England. Average speed was about 70mph. The computer showed that I got 22.9 mpg, and my calculated mpg based on the fillup after arriving at my destination was 22.98 mpg. After having driven the 410 miles, the range indicator was saying that I was good for another 57 miles. That's pretty decent. Was using Exxon super premium.

15 stop and go
23 mpg on highway.

see this thread also

https://www.clublexus.com/forums/gx-...-gx-today.html

Be careful not to overfill the tank. Trying to force additional fuel into the tank could push fuel into the EVAP system. This may cause a check engine code and/or may require the replacement of some EVAP system components.

Koz