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Sport mode eliminates it completely. Only at lower RPMs, around 1500 to 1800 do I feel this stuttering and howling from the engine. The tranny no doubt is mapped to keep the RPM as low as possible for mileage purposes. Every loaner RX and even the RX I owned never exhibited this.
Other than this my 4RX runs smooth as expected at highway speeds. Only happens when under light to medium load around 1800-1900 RPM.
"Every loaner RX and even the RX I owned never exhibited this".
do you mean your 2016rx loaner don't exhibited this? or 3gen rx?
I have the F sport and having some problems, as posted in another thread. However, I am curious wether any of your cars are switching gears hard. Not like where you just feel it, but where it is hard and you know it isn't right. This is one issue I have, sporadically, and was told by the service department my car is running fine. Happens no matter wether in Eco/sport or sport +
Have to point out the 2015 is six speed while your 2016 is eight. From my experience the eight speed in the 3RX F-Sport had hesitation too. There's a thread about it in the forum. But I didn't feel it in a 4RX F-Sport I recently test drove. If anything I think Lexus improved the transmission.
It should not have anything to do with how many gears a vehicle has. I owned and drove BMW's with 5,6 and 8 speed transmissions. If anything, the 8 speed BMWs are the fastest *and smoothest* accelerating vehicles which I have driven.
I find it shameful that Lexus stores and HQ are giving all of you and I now see myself as well a 'brush off' that the hesitations and mis-shifts during accelerarion are somehow normal and should be acceptable. This combined with the engine 'drone' and vibration complaints which I too started noticing shortly after taking delivery of and leaving the dealer.
What is really sad is how long all of the new 2016 RX complaints have gone on without resolution.
This thread reminds me of a similar one on the GM forum. Lots of excuses why EPA was causing the issue but lIMO it's the manufacturer. Maybe some is the desire to get the highest EPA number but some car makers do a much better job and get the vehicle right first. Honda's 9 speed is bad but BMW, Audi and the new Jag F Sport shift very good. GM 15's with 8 speeds had terrible fuel and transmission mapping and hesitation, erratic shifting in city driving, etc. It's better on the 16's but still not right. A lot of owners went to aftermarket tunes for engine and transmission. There weren't any complaints about fuel economy after a tune but that doesn't mean that emissions were good. I noticed this issue test driving the RX and that's why I'm waiting to see if the 17's are any better. That and the lack of Android Auto that many others have AA/Car Play or updates pending.
Bully Dog had tunes for prior gen Tacoma pickups with a supercharger so maybe the ECU isn't the "tight like a vault" that some report. A good tune might be just what these need.
I test drove the RX over the past weekend and it seemed very slow and hesitant from a stop. I tried accelerating from a stop multiple times and it just seemed like it didn't want to go. I thought it might have been a gas saving feature since the fuel light was on but this thread makes me think that's just how the car drives. Good to know. Thanks!
In Lexus NX, in the setting from the instrument gauge, there is a option for eco on/off. you can see the image here
i dont know if RX has that, if it does, try to turn it off and see if there is any difference
My experience after 3200 miles is that the hesitation and lag in my car is directly related to the gas I put in it. It is almost like a different tune the way it lags and surges on less expensive brands regular v premium from Chevron or Shell. Many years ago I had a Thunderbird that also ran noticeably better on some fuels. But for the most part in modern engines (German, US, and Japanese cars I've owned in the past 10 years) it seemed like gas is gas, just use the octane recommended. Not with my 4RX. Now maybe there is some kind of break in effect, or maybe it's just running better in the hot weather we're having for the first time since I bought it in February, or maybe it's the gas I put in it (accidentally - pushed the wrong button on the pump last time I filled up and got premium instead of regular) making it run so well. It's dramatically better now, making seamless shifts, idling smoother, not lagging after each gear change, not droning as much when in higher gears.
Mine never has had the vibration others describe here, so I don't know what to make of all this. I really thought the problem was "too many gears" for this much vehicle weight with the amount of torque the V6 is producing in this application. I owned 2 Mercedes with the 7 speed in them, both shifted quickly and smoothly - but both had V8 engines, one an AMG. I know Cadillac uses the same transmission in the current CTS (and maybe others) with their V6 and the ones I've driven shifted very nicely with no hesitation or lag. I figured the additional torque in a lighter vehicle made the difference. Now I'm not so sure. My 4RX feels like it should now, smooth and responsive in normal mode. I sure hope this isn't dependent on the hot weather. I'm happy to put more expensive gas in it in return for the smoothed out drivetrain response I'm experiencing now. Hope this can help somebody else.
My experience after 3200 miles is that the hesitation and lag in my car is directly related to the gas I put in it. It is almost like a different tune the way it lags and surges on less expensive brands regular v premium from Chevron or Shell.
Well this is very encouraging considering the dealer put Citgo 87 in it when I usually drive my vehicles almost exclusively on Shell 93 regardless of whether they need them.
Let's hope my mid pitched 'engine harmonic' (as my Lexus Service Manager described it) goes away too!!
In Lexus NX, in the setting from the instrument gauge, there is a option for eco on/off. you can see the image here
i dont know if RX has that, if it does, try to turn it off and see if there is any difference
I became hopeful and excited when I saw your post. Upon looking that up in the RX owner's manual, page 101 states that this simply turns on/off whether the *indicator* light will illuminate on the dash when Eco mode is active. It does not actually turn Eco mode off. Bummer
I sometimes feel it when doing a moderate acceleration from stop. And also right after shifting the gear to the next during acceleration, the steering wheel and gas pedal feel a little rough from some vibration. Once it goes to higher RPM or higher speed, everything is smooth again. This is more noticeable if drive in ECO mode. I only drove the car for less than 200 miles. Dealer filled the gas for me but not sure what type of gas. For next tank I will try the premium gas to see if it does the same or better.
It is just Lexus trying to squeeze every mile per gallon out of the RX by keeping the RPM VERY low. Great for EPA figures but poor for driving in the real world.
My experience after 3200 miles is that the hesitation and lag in my car is directly related to the gas I put in it. It is almost like a different tune the way it lags and surges on less expensive brands regular v premium from Chevron or Shell. Many years ago I had a Thunderbird that also ran noticeably better on some fuels. But for the most part in modern engines (German, US, and Japanese cars I've owned in the past 10 years) it seemed like gas is gas, just use the octane recommended. Not with my 4RX. Now maybe there is some kind of break in effect, or maybe it's just running better in the hot weather we're having for the first time since I bought it in February, or maybe it's the gas I put in it (accidentally - pushed the wrong button on the pump last time I filled up and got premium instead of regular) making it run so well. It's dramatically better now, making seamless shifts, idling smoother, not lagging after each gear change, not droning as much when in higher gears.
Mine never has had the vibration others describe here, so I don't know what to make of all this. I really thought the problem was "too many gears" for this much vehicle weight with the amount of torque the V6 is producing in this application. I owned 2 Mercedes with the 7 speed in them, both shifted quickly and smoothly - but both had V8 engines, one an AMG. I know Cadillac uses the same transmission in the current CTS (and maybe others) with their V6 and the ones I've driven shifted very nicely with no hesitation or lag. I figured the additional torque in a lighter vehicle made the difference. Now I'm not so sure. My 4RX feels like it should now, smooth and responsive in normal mode. I sure hope this isn't dependent on the hot weather. I'm happy to put more expensive gas in it in return for the smoothed out drivetrain response I'm experiencing now. Hope this can help somebody else.
I had some vibration in my ES. My service guy suggested it might be the gas. I switched from store brand to Exxon. It made a word of difference in both cars. Same octane.
I've thought of trying the premium gas for the RX but driving in sport mode gives me a powerful smooth take off.
I now have about 3000 miles on my 350 F sport and the car seems much smoother. I rarely get the vibrations at start and the hesitations. It seems like the transmission is learning my driving habits or Vice versa. Either way I find it almost acceptable now.
I think they did a decent job with the fuel economy/power and performance balance in this car. This car is about 500 lb heavier than my 4 Cylinder Venza, has 109 more HP, more torque and uses the same amount of gas MPG. At least for my driving.
I had some vibration in my ES. My service guy suggested it might be the gas. I switched from store brand to Exxon. It made a word of difference in both cars. Same octane.
I've thought of trying the premium gas for the RX but driving in sport mode gives me a powerful smooth take off.
Here's a post I made to the RX Hybrid forum regarding our choice of gasoline.
"Member dfc350 posted a while back about Top-Tier, which is an organization that helps ensure gasoline meets certain specifications, especially regarding additives. Members (like Shell, Exxon, etc.) must demonstrate compliance to these fuel standards. I read somewhere that some store brands, although they must meet federal additive concentrations, have a lower concentration of additives than some Top-Tier members. Apparently, the all important additives are introduced into the bulk gas at the local/regional terminal. The gas is then transported by truck to the member gas stations (the gas stations themselves also need to be compliant with Top-Tier guidelines. So, for example, in order for Shell to be certified as Top-Tier, all of their Shell gas stations must also be compliant with Top-Tier regulations). Our RX owners manual does recommend using a Top-Tier certified gas retailer although I'm sorry to say I can't find where I read that. I've been using a store brand gas (Regular) for my RX350 but I'm going to switch to a Top-Tier gas retailer for my next and subsequent refuelings. I'm going to try using a 93 Premium fuel to try to replicate billh556's positive experience using it."
I verified that the trucks which deliver the fuel to our local Shell station are different than the trucks which deliver fuel to our local "store brands" (Cumberland Farms and Stop & Shop). They're different companies delivering the fuel (just to be clear).
Last edited by Macs4RX; 06-06-16 at 10:08 AM.
Reason: Added content
Here's a post I made to the RX Hybrid forum regarding our choice of gasoline.
"... I've been using a store brand gas (Regular) for my RX350 but I'm going to switch to a Top-Tier gas retailer for my next and subsequent refuelings. I'm going to try using a 93 Premium fuel to try to replicate billh556's positive experience using it."
I verified that the trucks which deliver the fuel to our local Shell station are different than the trucks which deliver fuel to our local "store brands" (Cumberland Farms and Stop & Shop). They're different companies delivering the fuel (just to be clear).
May I ask whether switching to 93 Premium fuel and a Top-Tier brand made any noticeable difference for you when you did? Were you experiencing any issues/noise/roughness/hesitations prior to switching?
May I ask whether switching to 93 Premium fuel and a Top-Tier brand made any noticeable difference for you when you did? Were you experiencing any issues/noise/roughness/hesitations prior to switching?
Thanks
I still have a nearly full tank of "store brand" Regular gas in my RX350. So, no I haven't tried it yet but will next fill-up. There's some good information on the Top-Tier organization here. http://www.toptiergas.com/
And yes, I'm experiencing some of the driveability issues many others have previously mentioned: premature upshifts resulting in subsequent low torque, lagging and droning. But I believe this is a systemic issue and not unique to my vehicle. It's just the way the drivetrain has been configured and tuned.
billh556 made this interesting comment (quoted below):
My experience after 3200 miles is that the hesitation and lag in my car is directly related to the gas I put in it. It is almost like a different tune the way it lags and surges on less expensive brands regular v premium from Chevron or Shell. Many years ago I had a Thunderbird that also ran noticeably better on some fuels. But for the most part in modern engines (German, US, and Japanese cars I've owned in the past 10 years) it seemed like gas is gas, just use the octane recommended. Not with my 4RX. Now maybe there is some kind of break in effect, or maybe it's just running better in the hot weather we're having for the first time since I bought it in February, or maybe it's the gas I put in it (accidentally - pushed the wrong button on the pump last time I filled up and got premium instead of regular) making it run so well. It's dramatically better now, making seamless shifts, idling smoother, not lagging after each gear change, not droning as much when in higher gears.
02-09-16, 07:45 PM
