Leeladisky

All,

I have had an interesting experience that I wanted to share, as well as my conclusions:

As you know, Lexus employs some type of AI (artificial intelligence) which learns your driving habits and styles and makes changes to the shift points and engine management to receive the best posisble fuel and exhaust economies. The power mode supposedly increases shift points to provide additional acceleration and more aggressive shifting for passing and general driving. Personally, I always try the "ECT/Normal" mode first, which is the way the car is shipped from the factory.

After driving the car for quite some time in normal mode, I decided to try "power" which was an unbelievable difference in the feel of the car. Shift points were higher, definitely a more aggressive performance curve.

Recently, I installed a K&N air filter and, at the same time, reset the factory ECU so that it could "re-learn" the airflow characteristics of the filter. However, this time, I left the mode in "power" as opposed to "normal." Interestingly enough, I noticed absolutely no benefit from resetting the ECU - even in power mode after the reset the shift points were well below normal (compared to the former power setting) and it spent about 1/2 a second in 1st gear, regardless of how aggressively I applied the accelerator. The car felt/drove as if it was in "normal/ECT" mode as default from the factory, however, I actually had it in "POWER." All-in-all, it didn't strike me as odd, until....

I installed the Tanabe Exhaust which should have added 6-8 HP to the rear wheels. Again, I reset the ECU and left the vehicle in power mode. No noticeable performance/shift changes whatsoever - the car felt like POWER mode didn't exist (i.e., shipped from the factory in normal mode). However, this time I decided to switch back to Normal/ECT mode to see if it actually became WORSE. It made no difference whatsoever between the two modes...

Hypothesis: Power mode offers no benefit to the driver unless the vehicle has been driven for several days/100's of miles in Normal mode. My feeling is that the vehicle doesn't actually learn anything in Power mode and if there's no baseline data which can be improved for a "power" feel/mode, the vehicle will make no changes to the performance characteristics and therefore, no change whatsoever.

Experiment: I am now driving in normal mode (so far, for the last 24 hours) and have noticed no degredation in performance/power over my default power mode after ECU reset. I am going to leave it in this mode for another 24-48 hours and then switch back to Power mode to see what changes occur.

Conclusion: Forthcoming....

nardeezy

Intresting study. For clarification, document some of your data on a spreadsheet. I think it would be easier to understand but good work!

SGT

Very interesting, indeed. Let us know what happens.

Leeladisky

I will let you all know the result, tomorrow or Friday. The issue with a spreadsheet is that I don't really know what objective data I could capture that will display what I notice subjectively (i.e., shift points, delayed downshifts or lack thereof, etc.). Any suggestions would be appreciated and I'll try to implement...remember this isn't a dyno test - it's a "braino" test. LOL.

Lx2

PoppFlyy

Thannxx fior the well thought out thread Leela.
I look forward to reading more.

Leeladisky

Here's the news so far:

Yesterday, after refilling my tank (at $3.15/gallon ARGH!), I switched to power mode - I instantly - and I mean instantly - noticed a different power curve trajectory with higher shift points, etc. But, it wasn't like it was before I installed the K&N and had power on. I am wondering if the K&N filter is actually NOT performing the way the claim... nonetheless, it's hard to do a complete double-blind experient because originally I had 1500 miles on the vehicle before switching to power mode and another 1500-2000 miles before installing the K&N/exhaust combo.

I have now switched back to ECT mode (Normal) and will continue driving the vehicle for another SLOW 300-400 miles and then try again... we'll see if the updated, extended data improves things.

Additionally, i will shortly be removing the K&N and replacing with a Fujita F5 Shortram intake and a Blitz air filter... we'll how the power mode likes that.

Conclusion: I definitely believe that POWER mode is only effective if there's 1000+ miles on the vehicle driven in ETC/Normal mode. I have confirmed that the tranny/ECU learns either better in ECT mode or not at all in POWER mode and, therefore, it requires sufficient data to impove the curve. If you reset your ECU I highly suggest driving the vehicle for 500+ miles in stop/go conditions to allow the ECU to properly learn things.

I will continue to post results as I have them..

Lx2