GX460 - Top end struggles
03-18-19, 07:25 PM
#1
Pole Position
Thread Starter
GX460 - Top end struggles
last weekend I was coming home late.. was by myself. I was on a major interstate in PA and besides very few cars there was no body around. I was mostly driving the speed limit (set radar cruise) but there was an area where tractor trailer traffic was high and these guys would come over take me and come in front and the GX would brake( the radar cruise isn't very subtle in braking). I though it keeping up and possibly going faster than the big boys, I would go on a high end around at times (very flat roads) and open it up and felt the car was sort of struggling to remain at that speed. The only way I can explain is when you let your feet go off gas it comes back to lower speeds fast ( I don't feel that in the LX). maybe it was more wind in the opposite direction anyhow it didn't feel every safe so I went back to cruising at 65. i just turned the radar off and let the folks pass me 
and turned up my ML to some nice tunes.
How about you guys ? I know this is not really made for highway speeds I feel like the sweet spot for this car is about 55-65mph.
and turned up my ML to some nice tunes.How about you guys ? I know this is not really made for highway speeds I feel like the sweet spot for this car is about 55-65mph.
03-18-19, 08:38 PM
#2
Lead Lap
Definitely experienced this - just last week as a matter of fact.
If I am going 50-60mph and let my foot off the accelerator, it tends to gradually slow down. However, if I am going 75-85mph and do so, it's quite abrupt. Now I don't know if it was because I had my cruise set to 65 and had accelerated to pass a car and had not turned off or reset my cruise control, but it certainly was a jarring transition when I let my foot off the gas.
If I am going 50-60mph and let my foot off the accelerator, it tends to gradually slow down. However, if I am going 75-85mph and do so, it's quite abrupt. Now I don't know if it was because I had my cruise set to 65 and had accelerated to pass a car and had not turned off or reset my cruise control, but it certainly was a jarring transition when I let my foot off the gas.
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UZ214 (03-18-19)
03-18-19, 09:52 PM
#3
I would attribute this to the 6 speed gear box. I have a year 2000 land cruiser which feels like it has much better throttle response between 70-80, however, the GX without down shifting and a jarring response typically takes longer to accelerate. I have a 4 speed on the land cruiser and the struggle really begins at 78 mph if you want to cruiser at 3000rpm and get 12mpg. The 6 speed is at the cost of fuel economy and higher speeds at a comfortable level for the engine. Keep in mind the land cruiser has 230hp... gearing makes all the difference. I wonder if any of the guys with the pedal commander can chime in on how the radar cruiser reacts to it.
03-19-19, 03:57 AM
#4
I felt the same after a 500 mile road trip. However, I'm coming from a Jeep SRT with close to 500hp and 8 speed gearbox, so I figured it was just that. I guess I'll have to further adjust my driving style especially once the E-rated tires go on.
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UZ214 (03-19-19)
03-19-19, 09:18 AM
#5
There is a speed at which what passes for aerodynamics (or randomly comprises aerodynamics) on any vehicle "stalls" just like the sails on a sailboat sailing close to the wind. Above this speed, the vehicle becomes a true brick insofar as the air is concerned. I would guess that point must be no greater than 50 or 60 on a tall, boxy vehicle like the GX. It might even be lower than that. The deceleration from higher speeds can feel like an air brake under such conditions. You should notice that this air brake effect should attenuate as the vehicle slows to a range where the air begins to reattach to the body of the vehicle. Have you noticed that the back of the GX gets exceptionally dirty from road grime, etc. compared to other vehicles you have owned? Mine does. That's because there is terrific suction back there; the GX must be excellent to draft behind. Also, as noted, gearing may be involved. Also, check tire pressures.
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Bylan (10-19-21)
03-19-19, 09:20 AM
#6
I think it may also be the kind of soft feeling of the gas pedal. When I say soft I mean one needs to push the pedal a good distance to get a little oomph out of the engine. I know on mine I feel like I have to almost floor it to decent acceleration when getting on a freeway on ramp.
UZ214, Is this an issue all of a sudden or has it always felt this way?
UZ214, Is this an issue all of a sudden or has it always felt this way?
03-19-19, 02:09 PM
#7
Super Moderator
I can't say I have noticed this behavior or forgot about it since I have been running Pedal Commander. I'm normally around 78MPH on stretches of I-90 here in WA state. Only time I found issues was driving this speed with 40-45MPH headwinds. I slowed down for that. Vehicle does get especially dirty on the rear door. PC is simple to install and remove and money back guarantee if you don't like it.
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03-19-19, 07:22 PM
#8
I would attribute this to the 6 speed gear box. I have a year 2000 land cruiser which feels like it has much better throttle response between 70-80, however, the GX without down shifting and a jarring response typically takes longer to accelerate. I have a 4 speed on the land cruiser and the struggle really begins at 78 mph if you want to cruiser at 3000rpm and get 12mpg. The 6 speed is at the cost of fuel economy and higher speeds at a comfortable level for the engine. Keep in mind the land cruiser has 230hp... gearing makes all the difference. I wonder if any of the guys with the pedal commander can chime in on how the radar cruiser reacts to it.
OP, If you want to go faster at higher speeds, downshift.
03-19-19, 07:53 PM
#9
Pole Position
Thread Starter
Brillinat thinking, I actually never paid attention as to why it happens but yes, the back of the GX gets dirty every quick. The tire pressure was High at 38, I adjusted them today. BTW it seemed ok at 70 today but there was almost no wind. I think your explaination is point on.
There is a speed at which what passes for aerodynamics (or randomly comprises aerodynamics) on any vehicle "stalls" just like the sails on a sailboat sailing close to the wind. Above this speed, the vehicle becomes a true brick insofar as the air is concerned. I would guess that point must be no greater than 50 or 60 on a tall, boxy vehicle like the GX. It might even be lower than that. The deceleration from higher speeds can feel like an air brake under such conditions. You should notice that this air brake effect should attenuate as the vehicle slows to a range where the air begins to reattach to the body of the vehicle. Have you noticed that the back of the GX gets exceptionally dirty from road grime, etc. compared to other vehicles you have owned? Mine does. That's because there is terrific suction back there; the GX must be excellent to draft behind. Also, as noted, gearing may be involved. Also, check tire pressures.
Last edited by UZ214; 03-19-19 at 08:05 PM.
03-19-19, 08:03 PM
#10
Pole Position
Thread Starter
yea I feel that with this car both gas and brakes I have to "push" more than normal; I think its the same with als GXs. I have brand new GX standing in my home (my father in law) he's getting parking permit in NYC and I took it for a spin- same case.
I think it may also be the kind of soft feeling of the gas pedal. When I say soft I mean one needs to push the pedal a good distance to get a little oomph out of the engine. I know on mine I feel like I have to almost floor it to decent acceleration when getting on a freeway on ramp.
UZ214, Is this an issue all of a sudden or has it always felt this way?
UZ214, Is this an issue all of a sudden or has it always felt this way?
03-19-19, 08:05 PM
#11
Pole Position
Thread Starter
car was able to go faster, it was more an issue of putting an effort to make It go faster- (keeping the pedal in and the pedals wants to fight back!!) I know sounds weird.
03-20-19, 01:22 PM
#12
Advanced
In my experience my GX can cruise all day at 90mph pretty effortlessly.
Foot to the floor it'll pull very strong all the way up to the limiter. Fuel cut at the limiter is fairly abrupt though.
But yeah it's a huge brick on wheels. You've gotta use more fuel to go faster.
Foot to the floor it'll pull very strong all the way up to the limiter. Fuel cut at the limiter is fairly abrupt though.
But yeah it's a huge brick on wheels. You've gotta use more fuel to go faster.
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MrTorgue (10-18-21)
03-23-19, 04:54 PM
#13
In my experience my GX can cruise all day at 90mph pretty effortlessly.
Foot to the floor it'll pull very strong all the way up to the limiter. Fuel cut at the limiter is fairly abrupt though.
But yeah it's a huge brick on wheels. You've gotta use more fuel to go faster.
Foot to the floor it'll pull very strong all the way up to the limiter. Fuel cut at the limiter is fairly abrupt though.
But yeah it's a huge brick on wheels. You've gotta use more fuel to go faster.
I found its very easy to speed in this vehicle. It didn't seem to feel like I'm going that fast.
I'm also averaging about 19mpgs.
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tbrasuell (05-21-19)
03-23-19, 05:15 PM
#14
Lexus Champion
Look at the power band. IMO this is generally under powered across power band. Spec'd ~at 300 Hp and ~ 300 ft-lbs. coupled with 6 speed gear box.
Personally I don't like driving under powered vehicle. My current SUV with smaller V8 bi-turbo gives ~430 Hp and ~430 ft-lbs. (particularly flat torque from 1800 rpm and above) If I install modified chip it can put out 600 Hp.
Personally I don't like driving under powered vehicle. My current SUV with smaller V8 bi-turbo gives ~430 Hp and ~430 ft-lbs. (particularly flat torque from 1800 rpm and above) If I install modified chip it can put out 600 Hp.
03-23-19, 06:57 PM
#15
Look at the power band. IMO this is generally under powered across power band. Spec'd ~at 300 Hp and ~ 300 ft-lbs. coupled with 6 speed gear box.
Personally I don't like driving under powered vehicle. My current SUV with smaller V8 bi-turbo gives ~430 Hp and ~430 ft-lbs. (particularly flat torque from 1800 rpm and above) If I install modified chip it can put out 600 Hp.
Personally I don't like driving under powered vehicle. My current SUV with smaller V8 bi-turbo gives ~430 Hp and ~430 ft-lbs. (particularly flat torque from 1800 rpm and above) If I install modified chip it can put out 600 Hp.
