CTLG

I've not seen this happen in my travels with this fine machine. I switch to and from modes all the time while driving and while in park. They seem to do the exact same things to the driving dynamics, regardless of how I activate each mode.

Can you try doing it again, intentionally and report back your findings?

Side note: I personally believe that it's plausible the ECU is limiting performance for a preset amount of time/mileage/or other dynamic factor. But, your engine will continue to "break-in" as it ages, which will increase power output and efficiency. The first few hours of a fresh engine's life determine it's future - This is due to the proper seating (or lack thereof) of the piston's rings. After that, the engine's bearings/cam shafts and direct contact parts will continue to "wear-in", thus increasing power/efficiency. This could be what you're feeling. Does it seem like a light switch? Because if it's directly from wear-in, the increase in power/efficiency would be gradual and like barely noticeable.

carderoni

I've switched driving modes while in D in both cars and never noticed a difference versus switching modes while parked.

johng99

I don't have as much time behind the wheel in both variations as the OP, but I did drive the RWD for an hour, and ended up getting the AWD (both 350 F-Sport). Admittedly the 8-speed shifts slightly quicker, and feels like it provides slightly better acceleration from a stop. I would bet that the extra weight in the front of the car inhibits the handling slightly at the limit for the AWD too.

But, I think it's important to realize that you probably get 95% of the performance and handling with the AWD version. So if, like me, you live somewhere that you kind of need the extra all weather traction, you really don't miss out on much. I've only had the AWD for a few days, but i'm totally loving it.

ujwal1989

I mean the sensitivity of the accelerator in the AWD was more than that of my RWD. Sorry that I explained it wrong. The difference was noticeable even in P or N, it does not have anything to do with the transmission set up.
One reason for this that I could if is that the Lexus didn't want a too sensitive accelerator on a RWD as it would lose traction easily as compared to the AWD. Do you think this is possible?
Again, I observed this as I have the chance to drive both the cars back to back on a regular basis.

Aeromotive

Would you care to give your opinion about both cars? If I understand clearly you find the difference between RWD and AWD not as important as carderoni noted. I'm waiting for my RWD IS350 in 20 days and I'm still wondering if I made the right decision. As I stated in the other thread I'm in Montreal and we get similar snow conditions to yours but our streets are cleared within 12-18 hours and roads are flat. Would you buy your RWD again for the difference in driving dynamics?

Slust

This looks to be what is going on, though possibly more related to how warmed up the car is. I will go into further detail while responding to CTLG but I wanted to quote yours because it seems fairly accurate.


Yes, repeatedable ...with notes. Tho to answer your last paragraph first, I have 4500ish miles on the car and it is already starting to break in nicely. Gas mileage has already improved.

What I see...

Cold start (car's been off for at least a few hours)
- While still in Park, turn **** to Sport/+ mode ...car shifts gears with typical Sport mode behavior
- Put the car in drive, stop car (still in drive), turn **** to Sport and it shifts like Normal mode for the first few minutes/miles and then switches to Sport mode shifting. I like to watch the gear the car is in on the Tach.

Warm start (car turns on with coolent still warm and low idle signature)
- It does not matter when I switch to Sport mode, it shifts like Sport mode

Driving in Normal mode and car is fully warmed up
- It does not matter when I switch to Sport mode, it shifts like Sport mode


So I think it's a combination of what you and Kuma are saying. I think the car's ECU is limiting full Sport mode until it is fully warmed up. Now it may only be limiting it if you switch from Normal mode to Sport mode while in drive, but the car's throttle response is definitely better once warmed up. Now whether that is the ECU limiting it or just natural mechanics on how autos normally operate who knows. Both make sense.

CTLG

This makes sense. I'll have to try this for myself. I've always put the car in ECO mode when cold, because I'm super-**** about pushing a cold engine too hard. Once the coolant starts to warm up, I'll switch modes if need be. It doesn't take long for the engine to warm-up to proper operating temps, it takes the coolant longer, so by the time the coolant temp starts to creep up, the actual engine is warm. The worst thing you could do to a totally cold engine is let it sit and idle until the coolant is up to normal temp. This is unneeded, unless you're going on a very short trip (like moving the car from one parking spot to another) - then allow the car to warm-up until the coolant temp starts to move up a few bars. This is especially important for a new engine. There is a fine line between allowing an engine to warm up and idling it for too long.

ujwal1989

I definitely would buy the RWD again. It is a lot more fun to drive even in snow, BUT winter tires are crucial. Even with the 2013-2014 winter, there was no trouble getting around the town. Ofcourse, the RWD is slower in snow off the line, but once you get going, there is absolutely no difference between the RWD (with winter tires) and AWD (All seasons). Infact the RWD with winter tires stops better and understeers lesser when pushed. You can get to higher speeds in snow on an AWD, but I prefer driving slow in snow (I think everyone would ).

The only time I faced trouble was during a snow storm in the Boston outskirts (Babson college campus to be specific). It had snowed heavily for 30 mins right after I parked the car and the temps were just below freezing leading to extremely slippery and slushy surface. Also, the Babson college area is hilly and the ramp out of the parking lot was steep (10-15 Degs gradient I would say). All these factors made it almost impossible for me to get the car out of the lot, which was maily due to the extremely sensitive TC of this car. I was able to get out once I turned the TC completely off and turned the snow mode on. Once I picked up speed, I had not issues even when the roads were steep.

I addition to the dynamics, you get better fuel efficiency and an electronically adjustible steering. (AWD has only manual adjustment as far I know). You would also be saving over $1500 which you can spend on winter tires with wheels and an Fsport exhaust. In short, you would be getting a better car for lesser money.

Slust

I do warm up the engine but only till the idle signature calms down (cold start it starts off around 1.5k RPM or higher) to allow proper lubrication. This is also about the same amount of time it takes for the car to see my phone and pair up - so about 30s. The one time I did get a Nav reboot it was when I shifted right away on a cold boot and tried to hit the volume button when the Warning screen was still on. So I wait 30s, which sometimes sucks I admit, allow the lubrication to set in and the phone to pair up and no issues. Only time I "warm up" longer than that is if I'm trying to deice my windshield in the winter time. I've heard the same thing you said that warming up the car is actually not good for the car ...not to mention it wastes gas.

So when I said a "warm start" I meant I just drove the car so the car has only been off for minutes or 1-2 hours and it's still pretty warm. Example, cold start going to lunch ...warm start coming back from lunch.

bp044

I thought i might like the VGRS. I am curious as to why you consider it "Kinda sorta funky "

carderoni

VGRS just boosts the power steering assistance depending on your speed. Granted, it's a more accurate system than you'll find on most other cars, but I didn't find it necessary after driving the AWD car for a few months. If you like a very light steering feel at low speeds (like in a parking lot) it might be right up your alley. I'm sure others that have lived with it can give you a more detailed description than I can.

bp044

I don't like a light steering feel. I assumed that it would give me a better " feel " of the road like the late lamented hydraulic assisted steering did. Am I wrong ?

carderoni

I haven't spent much time with a VGRS equipped car but it didn't seem to me like it imparted any more feedback from the road or steering feel. It's still an electric power steering system. A few of the members who have it swear by it while others thought it was kind of awkward in some situations, like on tight highway ramps.

carderoni

Just crossed the 4,000 mile mark so I figured it was time for an update.

Gas Mileage
This has been a hot topic on this forum from the beginning. After logging 5,000+ miles on the AWD vehicle I was averaging 20.9MPG according to the trip computer. Like many others I experienced improved fuel efficiency after logging a couple thousand miles. While nothing to write home about, this was a huge improvement over my Subaru Legacy GT, which was rated at 17MPG city, 22MPG highway, and probably saw about 18MPG combined.

As I noted in a previous post, I've been driving the RWD model in Sport and Sport+ mode more often - and pushing it harder - inspired by the more aggressive gearing and quicker shifting of the 8 speed transmission. Despite this I have averaged a surprising 23.8MPG according to the trip computer. Like the AWD version, this car has also seen improved fuel efficiency once the odometer clicked a couple thousand times. It's worth noting this car sees the same commute and same (roughly) 60/40 city/highway split as the AWD model, using the same JoeZ intake, with an oil change after 1,000 miles plus RSR Ran-Up.


Reliability
Not much to say here, really. The AWD car had a driver's side blind spot monitor failure around the 400 mile mark which was taken care of quickly under warranty by the dealership. No leaks, rattles, vibrations, or aberrations to report.

The RWD car has even less to report - it's been completely problem-free so far. I believe the BSM monitor on the AWD car was a fluke and, based on my limited mileage, both cars are as reliable and quality-built as a Lexus should be.


Other Stuff
As a side note, it's been nice to see a few more 3IS's on the road around here. Within the past couple of weeks I spotted a Matador Red RWD IS 350 F-Sport and just yesterday crossed paths with an Ultra White AWD F-Sport (unfortunately I could not get close enough to see if it was a 250 or 350).


Gratuitous beauty shot: