primecut

iTrader: (1)

Sorry, I'm not trying to be ignorant, but this is confusion regarding how to drive the car, rather than a problem with the software or the transmission. I have NEVER had a delay in downshifting. They are lightning quick. Furthermore, I've read dozens of car reviews and not a single one has mentioned of any delay with the transmission. Maybe someone who has tracked an IS-F can chime in (Flipside?).

If you are in auto mode, then the shifting will NOT be as responsive as in manual mode. However, if you are cruising in 8th in auto and you want to pass, the car WILL select the right gear and you will be able to get to where you want, and FAST. Therefore, if you don't know how to anticipate shifts or drive a manual, you should be in AUTO mode, not MANUAL. Some of those near accident stories sound like the driver should have been in auto mode because they were in the wrong gears and they are downshifting like they're playing gran turismo.

On the other hand, if you use auto, then you can't expect it to read your mind. You can't have your cake and eat it too.

Good luck!

ngl1145

Honestly she should have made sure she was in gear before pulling into the next lane. It's like if you were driving a manual car and changing lanes while having your clutch to the floor and shifting gears part way. Before I shift, I make sure I can do it and that I'm in the right gear. But glad she's ok!

BigMikeISF

I agree. The IS-f downshifts aren't the fastest they could be but I don't really have a problem driving around town passing people either in auto or manual mode, but thats just me

I notice the delay every once in a while, but oh well, I love everything else about the car

Good luck!

foup

I think there is a misunderstanding about the car "behavior". The car offers two modes, manual and auto for two different kinds of driving, the former for fast driving and the second for economical cruising. Shifting is extremely quick in manual, faster than with a conventional manual gear box.

It sounds like some wants a third mode like "be economical" but "unleash your power instantaneously" when I ask for it. Obviously this is not going to happen. If you are at 8th gear at 1500 RPM and seek to get to 4th at 4000 RPM it's going to take a while. It would take exactly the same amount of time in a Formula One or any DSG, Tiptronic or whatever car. I concede that a true manual allows you to go from 6 to 3 perhaps in one second and it may be faster than the ISF that may do it in 1.5 or 2 seconds. The race driver does not need that because the race driver rarely downshifts from 6 to 3 without passing by 4 and 5 (otherwise Formula One cars would not have sequential boxes).

I think what you are asking for is a "fast auto" mode that basically is an auto mode that shifts at red line or so. In such mode you would rarely be driving below 4000 RPM anyway and therefore you could unleash the power instantaneously or almost when you want to (and you would likely only have to downshift once if any).

Perhaps Lexus could engineer such a mode, after all it's just software. They probably would have to lock the torque converter too. But then people are going to complain that their car does 15MPG while cruising.

One other aspect of the problem has to do with emissions. My previous Mercedes was manual but drive-by-wire. To me "drive-by-wire" is evil because it kills the spirits of the car. Even on the Benz if I would press the pedal too fast it would "temper" my actions by introducing small delays. Some are due to the physics of the hardware (valves, actuators, solenoids, etc) but some are engineered in the software to avoid spurts of bad emissions. Put your car in neutral (while parked obviously) and press the pedal, you will see there is a delay.

It's hard to have the best of all worlds. But there is hope, Larry, try a Tesla roadster and you will see what I mean: there is no cruising vs sport mode, no torque converter, no gear box, no emission issues. At any speed and at any time you press the pedal and it flies you to the stratosphere instantaneously. You will wonder if you want to keep your planes after the experience...

larrysb

No, I do know how to drive the car. This is isn't a driver problem or a "read my mind" problem. It's a bug.

I've driven plenty of other slush boxes, but this one in particular, needs some software revision for down shift programming. It's slow enough to react in certain situations, that it is quite humanly-observable to see it has a problem. In fact, it's slow enough to react that I have time to look at the gear indicator and say outloud, "is this thing ever going to downshift?"

Seriously, if the car is in 7 or 8 and you stomp the pedal to the floor, it should not take it 2-3 seconds to downshift. I've done this plenty enough times to be sure that it is a bug, not a feature.

In fact, I noted this problem within a week of owning it, on a post here.

I don't think it is "broken" as in replacing parts will somehow fix it, but it is definitely a bug.

I've driven plenty of 6-spd autos, both domestic and import, and I didn't find the same problem. The 6-speed auto in the C6 Corvette is actually pretty good, as are many other cars with performance cars. There's no huge lag following application of throttle to get it down shift.

larrysb

You know my C5 Corvette was also drive by wire, with a stick. It was very well implemented though. The throttle motor opened very quickly and the only interference you might get is throttle modulation if traction control was invoked. The Corvette had a nice feature there, in that the display on the instrument panel would tell you instantly that traction control had been invoked, or stability control, or ABS. Very good feature, very good driver feedback.

I did NOT like the 4 speed auto in the C5, but the last year introduced the current C6's A6 automatic, which I found to be pretty good and more responsive than the F's programming.


I'd be interested to drive the Tesla, for sure.
But for $100k+, I'd pick a Corvette ZR1.

The difference between sportscars and airplanes: When you reach 75 miles an hour in a sports car and pull back on the wheel, nothing much happens.

ngl1145

I'm going to try putting the car in D sport mode later and keeping it 6th gear by clicking the paddle. In D mode it should be able to downshift gears for me. I'll have to see if it's more responsive. I do know the car likes to go to the highest gear possible and that's 8. By keeping it in 6th and stepping on it, the car should be more responsive. The 6 speed in my IS350 was quicker because it doesn't have 2 extra gears to skip down. Because we have 8, the car has to downshift past gears 7 and 8 to even reach 6th. I realize the gearing ratios between the 6 speed and 8 speed are different, but your car still needs time to downshift. It bugs me too!!!

foup

larry perhaps you can describe a typical procedure for us to test, what speed, what gear, how you floor it, how you measure the delay, etc. We'll see if that can be reproduced with other cars.

Just F Me

Hi everyone,,,,i don't own an IS-F nor do i even own a Lexus....however, i hope to own an IS-F in the middle of this month. Right now i drive a 2005 6-speed Acura TL....when i'm on the freeways, if i get in a jam, or i REALLY want to pass someone, i go from 6th to 3rd and punch it...no problems (i don't know how my tranny feels about it though).

But all this talk about the IS-F tranny not downshifting properly kinda scares me. I like having FULL control of which gear i'm currently in but i do know that when i need to make my way around traffic, i usually keep the car in 4th/5th gear and sometimes even in 3rd, until i calm down and drive like a normal person then i throw it in 6th.

But i think that IF i had an IS-F...i'd just drive it in sport mode and keep the gears low. I watched a Fifth Gear video and they say the car can do top speed on 5th gear (is this true?) So if you need some excitement while you drive, just stay in 4/5 and keep the car in the powerband, but like everyone has said, it can't go from 8th to 3rd like i can go from 6th to 3rd in my TL....limitations of the car i guess? at least your tranny will be happy 100,000k miles from now...

foup

Downshifting delays cannot possibly be a problem to pass someone unless someone appears in front of you in less than one second and then you decide to pass him still within a second or two, while you were cruising in auto mode.

Usually when you want to pass you have plenty of time to think about it. Say you are cruising at 60Mph at 1500 RPM in 8 th gear, click the left paddle 3 times to go to manual mode in 5 th gear, and when you re ready to pass floor it. It works very well.

And if you are afraid to find yourself in the first situation then simply keep driving on manual above 3000 RPM all the time but you will get tired of the noise and the low MPG.

primecut

iTrader: (1)

Don't worry about it. Like everyone was saying, there is time to anticipate your shifts. And like you said, if you are doing spirited driving, then you'll stay in the lower gears. Honestly, the F has massive torque, such that you don't need to downshift 3-4 times like you do in the TL anyways Most of the time you can pass without even attempting to downshift.

Nevertheless, I'd suggest test driving it and see for yourself.

ToothDoc

I don't know about you, but my car downshifts just fine in auto mode. I decided to punch the gas. I was cruising along at 42 mph in 7th or maybe it's even in 8th gear because I'm around 1100 rpm. I hit the gas and within a split second, I'm in 2nd gear and spinning my tires (you can see the traction blinking in the lower right).

Maybe your car has adapted to slower driving and mine's more used to more aggressive driving?

Here's a quick mobile phone video:

http://home.comcast.net/~youngsongdmd/nolag.3gp

larrysb

Weirdly enough, this happens in my experience, more often in "sport" mode than in normal mode.

I honestly do NOT believe this, or any other car, "adapts to the driver" in such a way that driving it a certain way over time will alter the car's firmware or programming in any permanent way. It's just not do-able from a computer science standpoint. It would also preclude multiple drivers from using the same car. Just doesn't make sense and someone is going to have to cite some evidence that the F "learns from the driver".

Look, I like the car, but it appears to have bug, which others have confirmed. It doesn't happen all the time, but it is repeatable that it does not downshift as expected in certain circumstances.

The first time it happened to me, I was going up a mountain road at about 35 mph, in sport mode, D selected. Slower moving traffic towing a trailer made a quick dodge to a turnout to allow me to pass. The turnouts are short, so I hit the gas and not much happened. I literally had time to yell at the car, "Is this thing ever going to downshift?" I had to pass an RV towing a trailer, so I wasn't thrilled with the ponderous response to driver input.

Bug. Not a show-stopper, but a bug.

I've been driving high performance cars pretty much my whole life, skinned plenty of knuckles working on them and have a pretty darn good idea what a software bug is.

BoGiE

Thank you for the video, because there is no way in he!! my IS-F has ever downshifted that fast. My 5th to 2nd gear downshifting takes 5x the amount of time it took your car to go from 7th to 2nd. I would be a VERY happy man with your shifting times. BTW, I just forwarded the video to the heads at my local dealership because this seams to be a hit or miss issue with IS-F's.


L

foup

ToothDoc,

When you have a chance, would you mind to shoot a new video that also shows the gear number (instead of the temperature)? That way we'll see better from where to where it downshifts. Then I will try on my car. Looking at your video it seems there less than 0.5 second delay delay.

There is no reason why another ISF should behave differently. Certainly that should prove there is no firmware issue (unless you have different firmware - perhaps you can tell when you bought the car).

Thanks.