7AT, 7th gear: Cruising or Top Speed?
 

Couldn't find anything in the search function, so slay me if this did exist!

But yeah, just wondering if the 7th gear is used for cruising or top speed. My commute on the freeway averages around 70~80mph and I noticed that even on 7th gear, the RPMs lick 3K. Constant 3000 RPM seems a bit high for cruising in my opinion.

:driving:

Yeahhhhhh... But that's just the way it is... The AT hits top speed of 155 in 5th gear

Wow, then this 7th gear is pretty silly. >_>

Surprisingly, I get better gas mileage not using 7th. The interstate I commute on daily is very hilly which causes you to basically floor it to maintain speed going up a semi-steep hill at 80mph. I find that if I stay in 5th I end up getting better MPG. YMMV.

Also, the FI exhaust in 7th up a big hill is fairly annoying on the inside :icon17:


Note: On normal roads, I get better gas mileage using 7th. On the hilly interstate is the only place it is worse.

It's because of 7th we get better gas mileage than MTs... Because 7th can be engaged at 42-43MPH

i can tell you that i can hit 155 in 5th on my MT

6th on MT and 7th on AT is really just overdrive, so its for gas savings

thats what i was gonna respond with. the last gear for a 6MT or 7AT is an overdrive gear for gas purposes. You could technically go without using those gears and still be fine.

Overdrive to improve economy and allow for better spacing of other 6 gears.

I only use it for highway cruising over 70 or 80 MPH.

5th on the 7AT and 6MT are 1.0 ratio, so 6th and 7th are technically both overdrive. Ever notice how the car shifts into 5th automatically if you switch into manual mode after cruising in auto? 6/7 aren't meant for acceleration, purely for fuel economy.

I see about 2400 RPM in 7th gear at 70 MPH.

What is this sorcery you speak of???

7th on AT is for gas savings.

I could run 180mph at 6th on a TT 7AT, but I did not filmed.
I don't know what is the limit of the automatic transmission, for this reason I don't give more.

I'll try to record the next.

Sorry my bad english :P

mine like to shift to 6th at around 110

The limiter on 7AT is 155MPH


And god bless you to buy a 370Z in Brasil, if I come can I stay with you???

(to our non Brasilians, the import tax is sonething like 500%, and you have to buy a brand new car... Can you say $200k 370Z?)

:iagree:

F that 7th is my highway gear. :icon17:

Small correction. Both 6th and 7th gears in the 7AT are both overdrives. Done for improved gas mileage. But I don't see any improvement from the VQ35 5AT, at all. :shakes head:

It's actually a much-improved transmission over the 5AT, there's some technical whitepapers out there from Jatco (the mfg of both). Mostly it's about improvements to the shifting speed/firmness, the downshift rev matching, and the full lockup stuff. For a fluid-drive true auto, it's really one of the best units out there. It's almost good enough to be a poor man's DCT/PDK type thing (which is what I used it for), but obviously a real DCT would be better.

6 and 7 are definitely cruising overdrive. Even 5th doesn't have a lot of umph, and I'd call it an "overdrive" too at the 7AT's rear end ratio, although if you plan to be full in the throttle past ~120mph you'll need to accelerate in 5th as well.

In 5th it will red line the 155 mph before you hit 7500 rpm on the dyno.
2800 rpm @ 100 kms with the 4.08s
z

I agree... but im not seeing the improved mileage... period. So they didnt achieve that. extra gears didnt help.

Does anyone know why they didn't make the ratios longer? Wouldn't you ideally shift into 7th around 60 or 65, that way your rpms would be under 2k at 75, thus getting even better gas mileage?

I don't get the bolded part, I mean you can shift into 7th at 42MPH.

I agree, especially when you have 7 gears... It's a joke... It should be so
Slow that it's barely above idle, just so the engine doesn't sputter and die, lol


I REALLY wish our cars had a little ball, or switch behind the gas pedal, so just in case you were in tiptronic and you needed to floor it, it would automatically shift ALL the way to the lowest gear possible. Maybe put that as a feature in place of the SRM button on the sport package? (Just off hand, BMW's, my Maxima, and the Porsche's I have driven have it)

Sorry. I meant make 65mph the earliest shift point for 7th, instead of the 42mph. Surely they know highway speeds are 70+, so it would be logical to have the cruising gear to only be accessed once you hit 65, thus allowing for the lowest rpms at highway speeds.

Yep, sorry, I misunderstood the logic when I first read it :tiphat: