Guessing others have probably noticed & discussed this, but just thought I’d pass along in case they haven’t.

Lately I’ve been wondering why my car, when supposedly ‘floored’ in automatic mode, kept short shifting in 1st & 2nd gears well shy of redline … at 5500rpm or so, even in Sport+.

Noticed today that you really have to firmly press down the accelerator as there’s a secondary buried button behind the accelerator pedal that fully unleashes the beast.

Basically, when stabbing the throttle, if during the last inch of travel you don’t feel some resistance followed by the feel of a button being depressed, then it’s not truly at full throttle. Just seems to be relevant to first gear or two - haven’t had issues getting to redline when passing on highways in 3rd or 4th gear. And obviously not an issue in manual mode.

I’ve had cars with similar secondary throttle mechanisms, but none had half the resistance of my IS500s, to the extent that up to today I had been assuming it didn’t have one.

 

Of course you were driving at a safe speed the entire time right?…… Right?


Im gonna have to try this…

 

Hum, I'll also have to look at this, been bugging me for a while!

 

This isn't just an IS500 thing. I notice the same thing on the IS350. It's when my little 6 Cylinder comes alive.

 

(Lmao) - That created an image....

 

Same I've encountered in other brands as well. It's like an "are you sure?" notch/hump at the end of the pedal.

 

Try turning traction control all the way off and shifting with the paddles in M mode.

 

Oh how important one more inch truly is... 🤣

Yeah, this car feels like like 98% of the gas pedal gives you maybe 70% of throttle. The last 2% with the button feeling gives you the final 30%. Me no likely. I used to be able to roll on the throttle in the C7 to help with launches or just for fun, but this car just gives you the middle finger and shifts lol no fun for you! Manual mode does solve all these problems.

Oh, and I would NOT turn the traction control all the way off unless you are very experienced at recovering oversteer. The backend likes to step out on this car quickly, there just isn't enough tire under it. I punched it on a sweeping turn yesterday and the backend wanted to come out at 45 mph! I felt it start to slip and the TC light started flashing. This car will surpass its limits quickly.

 

Does this mean our car goes past 150?

 

Agreed, even on the 350 that final bit of the gas pedal matters a lot. Paritcularly if TC is fully off, it definitely feels stronger if I go through the kick-down switch.

It's weird, since I'd think the kick-down switch is just that - for forcing a kick-down of the transmission. However, it seems like Lexus decided not to give us 100% throttle unless we hit the kick-down as well. For me, what's most noticeable is the feeling of "getting onto cam" is less pronounced when I have the pedal truly on the floor. Seems like I get more power everywhere if I have it fully depressed. Mind you, this is not something I do often.

I wonder if the 500 is like the 350 where TC subtly is intervening even when the light is not illuminated. A friend did some data-logging on his 2015 IS 350 and found that timing was being cut even while traveling in a straight line at highway speeds when TC was on. With TC fully-off, this did not happen. Same fuel. It's probably negligible in the real world but something to think about when tracking or drag-racing the car.

 

Yep…it’s a kick-down pedal. My ‘16 IS 350 FSport had the same set up, so think of the downshifting as a two-pronged process between it and the transmission. Without a purposeful press of the pedal, the transmission will halfheartedly respond. It’s a teeny-bit better in Sport+, but the kick-down still needs to be clicked to unlock the performance.

 

As for the OP’s original question. The transmission will probably let you hit redline without upshifting early if TC is off and you’re shifting manually in either sport or sport +. This how it works in the 350, so I’m assuming this may work for the 500, but someone should try it out.

This is all independent of the kickdown pedal as I’m sure you’re aware that you don’t need to floor the throttle to hit the redline.

 

... If in manual mode. Does it redline in auto mode? Maybe in Sport+? I know in the 350, I can't possibly hit redline if I leave it in auto. I have to use manual mode.

 

For the 350 you cannot hit redline in auto regardless of mode or even if TC is off. It only works in manual with TC off.

 

24 hours into learning this, I can only gety IS500 to hit redline in manual mode (which has always been the case) -or- if in the kick down pedal is engaged in auto mode. Traction control can stay on and still get to redline in auto mode, at least in my custom mode and sport+.

I had been able to get to redline in auto mode in 3rd and maybe 4th gear without the kick down pedal, but up to yesterday had never been able hit redline in auto mode in 1st or 2nd gear until I learned about the kick down pedal quirk.