Actually, I meant the opposite. I’m not sure how to word it differently. It sort of sounds like folks at lower altitudes (higher octanes) have more issues than those at higher altitudes (lower octanes), but I’m just guessing & have no real data on this. I’ve run some tests on my 450h using 87 octane & then having the dealer check the knock sensors logs. Nothing showed, so that told me, it’s not an octane issue. I don’t have this problem on my 450h, but some of the loaner 350s I’ve had, did have some problems, but they were not consistent.

 

Do you think that it may have something to do with the quality of the gas?

 

Yes, it could possibly be related to how much ethanol and/or additive is in the fuel. Too much will cause all sorts of issues. On my 450h, I get consistently better mpg when I run Top Tier gas. If I buy anything other than Top Tier, my mpg drops by at least 2 mpg & the car runs poorly.

 

Love my rx350 but hate the lethargic transmission. Recently took it to my dealership to seek some type of remedy and was told that my transmission needed an update. What a difference!!! The transmission no longer hunts for gears, instead it is prompt and assertive!!! The whole thing was covered under my powertrain warranty since my 16 has 50k. I would highly recommend if you rx is having similar transmission issues.

 

When they update the ECU, it is my understanding that it resets your driving behavior. In a few weeks, you'll start noticing the same lethargy you speak of. Resetting the ECU is only a temporary solution, unfortunately.

 

that's unfortunate even after the dealership reprogrammed the ECU. Is there any permanent solution?

 

I had the ECU update 2 or 3 years ago and 85 to 90% of the hesitation went away and stayed away. Maybe it hasn't yet figured out my non-linear driving behavior.

 

Trading it is the only solution that I know of. Unfortunately, Toyota doesn’t think it’s a problem.

 

I just purchased a 2016 RX 350. IMMACULATE. The most beautiful car I've ever owned. The only other luxury vehicle I've ever owned was an Infiniti, which drove like velvet. I touched the gas and was smooth acceleration. YES, I test drove the RX 350. Yes, I am a woman and was not paying attention to the acceleration. It's my fault, so let's get that out of the way now. The best way I can describe the RX350 is unpredictable acceleration. Doesn't matter whether I'm in ECO or SPORT, it is sputtery. NOT to the point of OMG my car is about to break down, just OMG this is so annoying. I brought the car back to the dealership (Lexus in Baton Rouge) and they checked the car over and assured me nothing was wrong with the car and that it probably needed a "reset" since it was not used to me, the new driver. I scratched my head, squinted my eyes and said, uh, ok. They said they "reset" the car and it should be "used" to me in about 200 miles. Well, it must hate me. Honestly, I hate it back. I paid about $5K more than I should have because...there are just no cars out there right now...and feel like I got screwed. Is this NORMAL for a Lexus? Am I being ridiculous? I'll just go back to my Honda Accord with 150K miles on it if this is luxury.

 

The ecu will have to learn your driving pattern and will adjust. Give it a little time and a couple hundred miles and see if it gets better.

 

Normal: https://www.clublexus.com/forums/rx-...ost-159-a.html

 

Curious if the reset ultimately helped in anyway. I'm in the same boat as you with my used 2017. The shifting up and down looking for the right gear makes me want to trade it after only 7 months. I like pretty much everything else about it but its driving me crazy.

 

After 11 months of frustration, I sold the car. I ended up buying a Rav 4 Prime. The ironic thing is the finance manger at the Toyota dealership has a Lexus with the same issues

 

I don't know where you are with researching this issue. Have you had the TSB done to update the software AND confirmed that it was done correctly AND that the correct software number comes up as the current one?

 

I haven't done anything - just inquiring if those who had recently done some type of reset were satisfied with their results and if their dealers charged them to do it. Based on reading through many pages of this thread and responses to a review thread I posted, the results are a mixed bag at best. I realize no car is perfect, (although I would state without hesitation that my old Infiniti M35 - it was a 2007 and even then had features that most cars don't have today - including the RX, was damn close) so I can either live with it or move on to something else. I'm torn because of the known reliability and quiet ride it offers.