carderoni

I have not had to deal with any snow in the RWD model yet. The AWD model with stock all season tires handled this winter's snow storms (each accumulating under 4 inches here in Virginia) just as well as my Subaru. I experienced only very minor slippage on the worst day.

I've driven the RWD car through sub 40 degree temperatures for a couple of days - one of those through some light rain - with no issues.

As for turning radius, I haven't noticed much of a difference in U turns. Being that the car is still so new I haven't driven it hard enough to tell if either car is more nose heavy or tail happy than the other, but I'll report back on that once the RWD car is completely broken in.

JDR76

Turning radius for the RWD is 34.2 feet, and for the AWD is 35.4 feet.

carderoni

One little difference I've noticed is that, when I turned off the AWD car you could hear a buzzing noise coming from under the hood that would last maybe 10 or 15 seconds. The RWD car doesn't do this. Does anybody know what that was? Maybe a fan for the transfer case or 6 speed?

AndyL

Does the buzzing noise appear every singe time when you turn off the car?

On my 2011 RX, there is a buzzing noise near the back of the car (still underneath) and it is noticeable when you are outside the car. It doesn't appear when you turn off the car though -- it appears occasionally and it occurs when the car has been idle in the garage for some time. Basically when you walk in the garage and it buzzes out of nowhere. I talked to the dealership about this and they mentioned some routine check of the AWD system and it is normal. If there is something wrong, when you turn on the car again, there will be some error message.

liqinwei26

I noticed the same thing. It sounded like some electric modular were working

Dark9t316

Not just AWD, my RWD makes the same sound.

carderoni

Is that a 250 or 350?

carderoni

We're getting pummeled today in the mid-Atlantic area so the IS is safely at home in the garage - with up to 8 inches of accumulation expected the RWD with summer tires would've ended up in a ditch somewhere. A dusting is one thing but I'm not that interested in seeing how it handles snow and sleet.

This past weekend, however, was warm and dry and, with 800 miles on the odometer, I was able to let the car loose on some back roads. While I haven't taken it to its limits yet, I was able to draw some early conclusions about how these cars differ when your foot gets heavy.

Transmission in Sport/Sport+ Mode
This car was, admittedly, more babied than the last. I didn't even try Sport mode until I was officially out of the handbook's 621 mile break-in period. But once I did, my expectations were both met and reset.

What do I mean by "reset"? First off, when in Sport/Sport+ modes, the 8 speed will not engage gears 6-8 when left to shift for itself. Fifth gear is equivalent to about half way between third and fourth in the 6 speed, meaning the engine is spinning at about 2,800RPM at 50MPH. For the twisties this is a good thing as the transmission is doing its best to keep the engine in its sweet spot - great fun coming out of any turn. For daily driving it's just not as useful.

Under the same conditions the 6 speed engages all of its gears, which means daily driving in automatic Sport/Sport+ mode is realistic or even encouraged. The increased throttle sensitivity almost felt like a necessity in that car due to its taller first gear. In contrast I've found that since the RWD feels torquier off the line, driving around in automatic normal mode is more satisfying than in the AWD version.

Where my expectations were met was in manual mode, and I don't mean for that to sound disappointing at all. The gushing reviews of the 8 speed's 100ms direct shift performance have not been overhyped. Shift responses and shift times are noticeably quicker and crisper than the 6 speed, more so than in normal mode. Having two extra cogs in the box can take a little getting used to, and more than once I found myself a bit lost in the gears, but this transmission certainly feels and performs like something built to take this car to another level.

Aeromotive

Thanks carderoni : that's exactly the information I was looking forward to find in my AWD vs RWD dilemma. So would you still say both drivetrains behave the same under normal driving conditions?
For example, how does the AWD 6th gear Normal mode compare to the RWD 8th gear Normal mode at 60mph cruising? Does the 8-speed run at lower RPM's?

Also do you feel the faster shifting in normal driving conditions in Normal mode/automatic? Or only in Sport mode/manual?

(I'm putting a lot of emphasis on normal driving because my daily commute to work is 90-95% highways).

Thanks again. Please post more information when you get the chance

carderoni

Top gear in both transmissions will keep you around the same RPM at highway speeds. In 8th gear you're right at 2,000 RPM at about 69MPH, which is pretty close to 6th gear in the AWD car. While my trip computer says I'm averaging about a 1/2 MPG more in the RWD car I think it's too early to make any declarations about real world fuel efficiency (I still have under 1,000 miles on this car).

Shifting in Normal mode is smooth and quick with both transmissions - any differences under everyday driving conditions are too small for me to tell. The 8 speed is more eager to downshift when you gas it, but it also has more gears to make use of so that's no surprise.

The biggest differences under normal driving have been better throttle response in lower gears in the RWD car and more predictable engine braking in lower gears in the AWD car. I almost always drove the AWD car in Sport mode because I felt like the increased throttle tip-in was how the car should've felt in Normal mode - the 8 speed's shorter ratios make first and second gear feel almost as punchy in Normal mode as the 6 speed does in Sport mode. I also have a habit of manually downshifting when coming to a stop and have found that the amount/force of engine braking is more linear from gear to gear with the 6 speed.

Aeromotive

Thanks again for your informative post. If you had to do it all over again, would you pick AWD or RWD?

carderoni

No problem, I'm glad this thread has been helpful for someone.

Personally, I think I would pick the RWD again but that statement comes with a lot of caveats. I live in an area where we don't normally get a lot of snow, this winter being an exception. I also have access to an AWD vehicle, so having that feature on my daily driver isn't critical (though I do plan to get a set of wheels and winter tires for the 3IS). The 6 speed in the AWD is still a very good transmission. If I lived further north I'd opt for the AWD without a second thought. And if a future version of the 3IS combines AWD and the 8 speed transmission I would absolutely buy that.

jay631987

Hi carderoni, have you noticed any torque steer when driving it aggressively in the AWD or RWD versions?

viNz86

Thanks for the info carderoni! Would love to hear more information comparing the downshifts between AWD vs RWD and the auto-blip from your experience.

carderoni

jay, I think I posted in your thread already but if anybody is curious I never experienced any noticeable torque steer in the AWD car. The AWD system defaults to 70/30 rear/front (thanks redraptor for the clarification) and only sends a max of 50% of available power to the front.

With better weather on the way, 1,200 miles on the ODO and fresh oil I plan to get on the RWD car over the weekend, so hopefully I'll be able to give you a better idea of the differences between the two cars under a heavy foot relatively soon.