lexusUS1

Caught this forum as I googled for the Lexus Lurching problem. My wife recently purchased a 2005 ES300 in 02/05 and within 2 weeks started to have the problem discussed herein. We ignored it for awhile until it continued to worsen. As with many here, it became very annoying and dangerous with time. Today we took it to the dealer for a review. The "fix" was as follows: "Test drove car. Found to be lagging when accelerating from a stop. Recalibrated ECM to reduce downshift lag when accelerating at speeds from 10-20MPH. Less gear hunting when driving on/off accelerator at 20-30MPH. Improved response rate during heavy acceleration from a stop." After reviewing the TC004-04 that was posted in this site, I believe that is what they complied with. I now find that the car idles at a slighly higher RPM in drive when stopped but the lurching has disappeared. Now I find that the general overall engine/transmission reponse is squirly at moderate cruise speeds of 40-50MPH as if it's searching for the right gear setting or throttle position. I told the wife to anticipate a reduction in gas mileage. The Dealer also told me it was because of the octane gas we were running in it. The manual says 87 Octane is OK yet the Dealer says the car was designed to run on 97 Octane for best performance. This little tid-bit was not disclosed, not really sure if it's true anyway, but nontheless, it was not disclosed on the sales information sheet on the window nor did the salesman mention this at the time of the purchase. I can understand if the engine was retarding to compensate for an engine ping, but this is not the case so the octane grade shouldn't matter. I am very surprised as the amount of postings here as well as on the Lexus Owners Club UK, that Lexus hasn't addressed the issue a little better. In the UK, people are returning their cars and demanding refunds. I for one will not take this problem as a "Lexus thing" being the car is $40k+. And finally, it can be very dangerous if you are not able to judge your vehicles next movement, speed or lack there of to either one.