EBMCS03

Anyone know if our Transmission, specifically the IS 350's can skip gears when downshifting? Say I floor it in 6th can it skip 5 and just goto 4? Or does it still go 6 5 4 really fast? I was doing that on the freeway today and I noticed the Gear screen goes from 6 to 4 but that doesnt necessarily mean that the transmission skipped 5th...

kensteele

i'v never seen it skip.
i guess i should have said "felt" it skip.

TimboIS

Considering it's a SEQUENTIAL transmission, that pretty much says it all.

EBMCS03

Well damn... then the new 335 transmission is better.

IS3CM

I guess you could say its skiping 5 gear when you step on it in 6th gear. If you were doing 35 mph in 6th gear and you steped on the gas to pass, the car might even downshift from 6th to 2nd depending on how far you push the gas pedel down and what gear the computer feels like it needs to go to to get the acceleration that the computer thinks that you want. If you push the pedel down a little it might only downshift one gear but you push the gas to the floor and the car will downshift to the lowest possible gear to get the fastest acceleration that the car can provide. Works just like you shifting a manual and going from 4th to 2nd. Hopefully this helps.

EBMCS03

Right... What I was wondering was but does the car physically go from 6th to 2nd or does it go through 5 4 3 really fast and then to 2nd.

In a manual I can physically move the stick from 6 to 2 and not go into gears 5 4 or 3.

As smart alac Dumbo I mean Timbo noted above... the transmissions is "sequential" I dont know if it is or not... can it physically Skip Gears...

I know the new tranmission thats going to be used for the BMW 335Ci CAN physically skip gears.

kensteele

i don't think anyone here knows that answer for sure. it doesn't appear to go thru each and every gear when you step on it in 6th as suggested above, seems to go right to "3rd" or whatever....but who knows for sure. does it really matter if it's quick?

The Chad

When I test drove the 350, it didn't seem to hit any of the gears when I mashed the go pedal. But it's possible in the brief time it took for the downshift that it physically selected each gear before finally getting into 3rd.

What would really make the transmission better would be if it "blipped" the throttle on downshifts like the ZF transmission in the Aston Martin automatics and the Range Rovers.

It seemed like a seemless downshift in the IS, and I agree, if it feels seemless does it really matter if it is or it isn't?

TimboIS

Quote from How Stuff Works...

"you have to shift in sequence. There is no skipping, for example, from first gear to third. You must always go through second gear to get to third gear. It is the same when downshifting. The advantage of this system is that shifting mistakes are impossible. You always go to the next gear."

But in the end, like Chad says, does it really matter?!?

HaveBlue

Automatics skip when up and down shifting if necessary. The bands disconnect and the appropriate gear is selected based on inputs. Old trannys did this with a TV valve and a governor. New ones do it with a brain and solenoids. The tranny is no more different than most other auto trannys. If you've ever disassembled a motorcycle tranny, you'll see that they cannot physically skip gears. They have to go through each but you don't have to release the clutch.

EBMCS03

Sure it matters... if it skips its "faster" no matter how fast it already is... also if it can skip it shows how advanced our tranny is. AND its good info to know. YOu know how much HP and how much TQ the car has... you know if you have NAV or not Why not know if your tranny skip gears?

As noted since the IS tranny does not rev match like the Aston or RR autos OR the Infiniti Trannys also makes it seem not that "advanced"

What I dont get is why do some of you bash people ie. me when I ask more technical questions about the cars... Or do comparisions of it between other cars. I find these kind of topics probably more intriguing than "What Shade of Tint I should use?" topics.

As for Timbo keep insisting on trying to inform me what the defintion of "sequential" means save it. I know what it means. My other car is a Sequential Manual Gear Box and I know that cant skip gears but it Rev matches and goes through the gears. BUT is the IS tranny sequential or not, show me documentation. I seem to believe what HaveBlue posts more than just people going off 1 word "sequential" with out proof and trying to tell me the car doesnt skip gears. I need more proof than that word.

onihc

iTrader: (1)

There is a difference.
Sequential gear boxes on cars are "semi-automatics" that has at least one computer operated clutch.

Automatics, such as Lexus, has torque converters. Just because IS has paddle shifters, does not make them sequential transmission.

The Chad

When I agreed with someone and said "does it matter?" I wasn't implying that I thought your question was stupid. In fact, I would like to know the answer myself. But the fact of the matter is that it doesn't shift as quickly as a DSG-equipped car or even an SMG-equipped car. Also, like I said, though I only have briefly driven the IS350, when it downshifted from 6th to 3rd, it did it just as quickly as any other automatic I have driven, and I didn't notice any change other than the one major shift. There was no application of throttle after each gear change if there actually was more than one.

Personally I would like the see Lexus use a DSG-type box in their cars, especially the IS, because after driving several DSG-equipped cars, the shifts are so quick and so smooth that it was almost impossible to tell the car shifted.

But back to the subject at hand. A torque-converted automatic, no matter how intelligent through rev matching and gear skipping, will never be as quick to shift as a good driver in a manual or as an SMG or DSG car. The Lexus transmission felt pretty good and pretty responsive considering that it may not be as "intelligent" as some of it's competition. My point for saying "why does it matter if you can't tell the difference?" is that it's still hindered by the torque converter. No matter what, that will be a disadvantage to this car over the Bimmer for example, because you can get the Bimmer in a full blown manual, and you cannot in the IS350. And if you're in a situation where the milliseconds of shifting really matter, the IS probably isn't the best choice in car.

Not trying to bash, because I agree I would like to know the answer, just I can see why there isn't a rush to find the answer either.

That's all.

EBMCS03

Are you telling me? Or general comment?

EBMCS03

Not trying to rush. Its just that if no one knows the answer than we can discuss the matter looking for hints of wether the transmission is one way or another... or let the topic sit for a while and see if anyone who DOES know the answer chime in.

Saying "Does it matter" indicateds or hints to the fact of "who cares?... why does it matter?... why even bother asking?..." You see what I mean?

And yes you're right it wont be as fast to shift as SMG or DSG but knowing is half the battle. Its good info.