chandlervt

Same thing happens with NX. As one poster suggested, its because the car cannot find the right gear. This usually happens if you try to accelerate really fast from stop (or from slower speed). You may want to switch to sport mode if you want to do that and see if that resolves the issue.

RXOwner

I have also found that while in "normal" mode and you need quick acceleration, you can push the shift lever over into manual which drops it a gear or two and you are right where you need to be in the rpm range to move quickly. I find it great for turns where the RX always seems to be a gear higher than it needs to be when you make a 90 degree turn.

tava

Could you post it after you get the service for hesitation?

barx

I'm noticing the same problem - hesitation and vibration at lower speed and climbing hills. Feels like when you're driving stick and in a non-optimal gear. Harder to diagnose b/c the display doesn't tell me which gear I'm in.

Eco mode is the worse. Normal mode feels slightly lacking, and Sport mode feels overly aggressive. Would love to hear insights from whoever has their first service appt. We're only at 600 miles, so we're a ways away.

I hope it's something that Lexus can and will easily update with software.

RXOwner

I think Lexus, in trying to get great EPA numbers, mapped the tranny to shift way too soon in normal mode. Seems to want to keep the RPM around 1250 which is too low for any kind of acceleration. I am finding myself pushing the shift lever to the left to drop it a couple of gears rather than just push even harder on the gas.

I doubt the Lexus will fix this as their new 8 speed is helping their EPA numbers. It needs to be somewhere between normal and sport, wish that **** was adjustable in between! Accelerating gently is the worst, get a little more aggressive with the gas on starting out helps.

Macs4RX

The F-Sport has, in addition to Eco/Normal/Sport/Sport + modes, a Customize mode whereby one can adjust the Powertrain, Chassis/Suspension & Air Conditioning system independently. Wouldn't it be awesome if each parameter could be infinitely adjustable?

Unfortunately, this won't help RXOwner who I believe has the Luxury. And it still doesn't provide an option between Normal and Sport.

sc400

I haven't tried this on the 4th RX but on my 3RX, flipping the transmission to Manual from D would show the gear you're in when driving.
This doesn't hurt anything. It changes from auto transmission into shifting yourself.

dchar

Anyone else feel that the transmission is very laggy even in manual mode. I tried it this weekend, and there is a 1-2 second delay from when you upshift or downshift with the lever in both normal and sport mode. As you accelerate in first, you push the lever forward at 4500RPM, but it doesn't accomplish it until almost 6000RPM. I guess it's fine for people who just cruising around town, but annoying for when you want to have a little fun. The programming on the RX350's 8-speed is completely different than the 8-speed on my GS350.

RXOwner

Prior to the 4RX I used to downshift when, for example, coming off the highway on the exit. I found the 4RX slows very little downshifting so I no longer do it. The tranny is not lightning fast shifting but for the average driver it should be good. To tell you the truth, I would have liked to keep the 6 speed in previous RX units.

The is no RC-F but I sure enjoy driving it.

tava

I have 16' RX350 FWD. it has been running about 3000 miles so far.
Does anyone have experience about stuttering at around 40mph? I've felt several times at accelerating and climbing uphill.

What about hesitation? This one is pretty stressful issue for me. One of my experience: It doesn't feel like I'm driving with V6, 3.5L engine. Especially, when I accelerate the pedal at the starting point, rpm goes to around 1500 - 1700 rpm, but the car's response is not as I expect. This is the same at the various speed range.

Please tell me, how's your car?

RXOwner

I do not feel it at just 40mph. It can come at any lower speed where the rpm is under 2k and you apply enough gas to get over the hill or accelerate but not enough to to make it downshift. Does it while under medium load.

At lower RPMs, under 2000, you can not only feel it but see it on the tach. The RPM will jump up and down about 100-200rpm. Give it more gas and it gets worst until you push the pedal to the point it downshifts. This can be rather disconcerting as the 4RX wants so badly to keep the rpm low.

Going up a hill where you are under 2000 rpm and adding a little gas will do it bad enough that I not only feel it but can see the rpm changing on the tack. This will also be joined by the "howl" from the engine unless you force it to downshift.

I will bring this up to my dealer in a few weeks at the 5K. I have driven many RX loaners and even owned one and never felt this excellent 6 cylinder do this. I have even tried a tank of higher octane with no change in this studder.

Macs4RX

I'm wondering if the 450h suffers from this issue? At 1500 rpm or so, wouldn't the hybrid have an abundance amount of instant torque?

corradoMR2

tava and RXOwner, sounds like the tranny is geared for fuel economy over anything else. Determine if this is the case if the behavior is non-existent in Sport mode or in manual mode.

RXOwner

Sport mode eliminates it completely. Only at lower RPMs, around 1500 to 1800 do I feel this stuttering and howling from the engine. The tranny no doubt is mapped to keep the RPM as low as possible for mileage purposes. Every loaner RX and even the RX I owned never exhibited this.

Other than this my 4RX runs smooth as expected at highway speeds. Only happens when under light to medium load around 1800-1900 RPM.

bootman

That is the 8-speed trying to get you the best eco. It is doing its job just learn its habits and adapt when in eco mode.
if not, stay out of eco and keep it in sport.
Now if you want the best gas mileage but want to keep your foot down you and I both know that isn't happening.
gas is cheap now. enjoy.