More gears = less jump in rpms b/t gears to reach the same speed = smoother. So yes, the 5 sp would be rougher (or what you're calling aggressive/racy)...just not necessarily faster.

 

You just called "rougher" aggressive/racy, not me. Please don't try and put words in my mouth.

In theory the lower 1st gear in the 7sp should accelerate faster... heard it all before. Theory to practice... try it.

Again, have you driven each within 5 minutes of each other?

 

So a 4-speed auto would be really fast? The trend for better performance and fuel economy is more gears. There is a limit, I suppose, but I don't think it's 5 gears.

You like your 5AT, I like my 7AT. I think the 7 speed is better. To each his own.

 

Seriously, that's you're train of thought? More gears is better? Ever drive a continuously variable transmission? Those are fast...

I'm glad you like the 7sp. You're right, to each his own. The OP asked what the difference between the two years were and what he should be considering when buying. I provided my input for the OP from what I experienced.

 

I'm sure you didn't run a 1/4 in them 5 mins apart either. Flatter torque curve = less "thrown in your seat feeling". Doesn't mean the 5AT is faster. Your butt dyno don't mean ****.

Here's an official Edmunds article...
2009 Infiniti G37 Sedan First Drive on Inside Line

Just in case you missed the part about the gear ratios:
"Compared to the old five-speed, the seven-speed automatic has significantly shorter 1st, 2nd, 3rd and 4th gear ratios. In fact, it's geared more aggressively than even the six-speed manual gearbox...Infiniti says the 2009 G37 sedan should be a couple tenths of a second quicker from zero to 60 mph"

Forget about what you're "feeling"...numbers are numbers.

 

"Infiniti says it should be"... where are their numbers?

Besides, my butt dyno that you keep harping on has 35 years of calibration. I got it dialed in. And for your information, it wasn't even close.

 

anecdotal evidence is great and all, but the consensus among car journalists is the 09 7sp is a tad quicker than the 08 5sp. i believe their measurement devices are calibrated and quite accurate as well.

 

And let me guess...the world is flat because your a$$ tells you that too.

The point is, you're gonna think its slower if the torque curve is flatter. Just cause you "feel" something doesn't mean thats what's going on.

 

I know what your point is and you are correct on the shifting feel making the car "feel" faster. But there was a lot more going on than just the butt dyno.

Ok, let's forget about which one is faster for a second. The 5sp was a ton more fun to drive. It might even be slower, but it was without a doubt a ton more sportier than the 7sp was. She ruled out the 7sp during the test drive because it wasn't as fun to drive. She's the one who bought the car.

 

I can agree on that.

 

If we were talking race cars, less gears is actually faster b/c the car doesn't have to shift. For example, 2/3 speed PowerGlides and TH400s that Supras upgrade to for drag racing. Course, they're geared primarily for acceleration and don't make the best daily driven cars...Then again, they weren't designed for such. This would not apply to the current 5AT vs 7AT debate...especially since the 7AT gearing is more aggressive.

 

I disagree. The shifting does still apply in the street cars. With such a soft shifting transmission, more gears is felt just that much more.

The more aggressive gears should be a help but if the transmission is spending a lot of time in overlap between gears, then the more aggressive gearing is negated. If the shifts were instantaneous then I wouldn't have an arguement.

 

I don't disagree with what you're saying...I think you're just misunderstanding what I mean by does not apply. I'm saying it doesn't apply because the race tranny may only have 2 gears, thus most the time its in the upper revs. That's not a street car for daily use.

Of course, the more you have to shift, the more time you're gonna lose...but that's also dependent upon where your peak power band is. You can have less gears, but if you fall out of the peak powerband then its gonna be slower. If you take Infiniti's same soft shifting/same top speed/final drive/etc and tried to apply it to a 2 speed transmission, it would be slow as hell as you're not making much torque/hp in the lower RPMs during daily driving.

If the 5AT had more aggressive and properly geared gearing than the 7AT, then my money would be on the 5AT in a full out race since it wouldn't have to shift as much. But it doesn't (probably due to the trade off b/t acceleration and top speed gearing). The 5AT ends up being out of the peak powerband more often than the 7AT...And thus why the 5AT may feel "sportier" since there's more of a variation in torque. Plus the gearing for the 7AT is not overly overlapped. If we had dual clutch transmissions, the gap between the 7AT & 5AT would be much more apparent.

 

OK, I think I understand what you were getting at. And we haven't even started to talk about the weight difference between the two transmissions. (Mostly because I refuse to believe the 7sp is as heavy as the published numbers say. I don't think it's possible for it to be that much heavier.)

 

I test drove an 08 G37 S Coupe before buying my 09 G37x S sedan. I thought the 7AT made a big enough difference that it was noticeable, especially when using the paddles. It wasn't that there was anything wrong with the 5AT; it was aggressive, smooth...very nice. It's just that those two extra gears added a little more punch and the downshift rev-match is just straight-up fun.

Just my $.02, but I'd go for the '09 with the AWD.