wavshrdr

It is likely the transmission logic. This issues work nicely with the huge hesitation it has when you want max acceleration from a stop.

Mustachio

I'm sure this has already been answered but it's a result of having a dual clutch transmission. The second clutch essentially prepares the next gear it thinks you'll need on reserve for a quick gear change. If you are braking, it will assume you need a lower gear next, but if you are braking then try to quickly accelerate, the transmission needs to correct itself to give you the higher gear, hence the hesitation. You also may have noticed if you slam on the gas pedal immediately after decelerating, you'll red-line and have no power. That's because it already had the lower gear on reserve, and by slamming the gas pedal down you're basically telling it to hurry the F up and think, but it gets nervous and gives you what it already has prepared...the lower gear.

The bottom line is to be nice to your transmission and give it a moment to think. You don't have to drive like a grandma but by simply easing into acceleration for the first second, you'll eliminate most of the lag. There's a lot of benefit to having a dual clutch transmission. It's good to understand how they work to avoid damaging them.

Funz51

Wow, I think you hit it on the nose! thanks.

wavshrdr

I think you are mistaken about the RDX having a dual clutch transmission (DCT). I am almost 100% certain it doesn't. First off compared to a DCT is shifts slow AF. Second, a DCT can skp 4 gears on a downshift as Acura claims.

I'll add I've had several DCT equipped cars and bikes and none of them had the issues with hesitation or slow off the line acceleration.

Here is an article in C&D that talks about it and one from Wards. Quote from Wards "Honda’s 10AT is notable as being the first planetary automatic transmission manufactured by the automaker". Notice it says planetary and not DCT.

https://www.caranddriver.com/news/a1...-clutch-pedal/

https://www.wardsauto.com/technology...e-10at-odyssey

Also not the rated torque capacity of 275 lb/ft. I hope they have more headroom for the trans than this or the modded RDX's are going to grenade the trans.

RDX-Rick

And this PAGE from Acura lists the models which do have DCT's

Also this PAGE which has the RDX specs, says


While the specs for the TLX on this PAGE says

Wander

The 2019+ Acura RDX has a conventional planetary gear automatic transmission, with 4 planetary gear assemblies, 10 forward speeds and one reverse. It's actually the first time Honda has designed and manufactured a planetary gear AT. The ZF 9AT is also planetary gear.

A DCT has zero planetary gear assemblies. It's like 2 manual transmissions running in parallel. Some have torque converters, some don't.

https://www.wardsauto.com/technology...e-10at-odyssey

https://gearsmagazine.com/magazine/p...ts-in-a-honda/

I think there is confusion about the "two-way clutch" in the 10AT, but that's not the same thing as a dual clutch transmission design.

MT-RDX

If you really suffer from boredom or a techno-freak weakness, the link below is a good way to burn up an hour's time.
The RDX transmission is not a dual-clutch design, but a conventional automatic. Each design has advantages and shortcomings. While the transmission is a credibly good design, Acura has missed the boat with the transmission control module/software, which coupled with the turbo lag, does make the RDX fall short in stop and go city driving. The highway performance, however, is stellar beyond words, as the transmission provides a seamless and enjoyable high speed driving experience. As always, opinions may vary.

fiatlux

Honest question: has Honda ever made a non-DCT automatic transmission that performs well? I'm not talking about durability or drivability, I'm talking about shift speed, responsiveness, performance, etc. For the life of me I can't think of one. I can't think of one that is even comparable to the Aisen 8AT, let alone the ZF8,.

Wander

Aside from DCTs and CVTs, all of Honda's previous automatic transmissions have been robotized manuals. And they got darn good at them, IMO. There's nothing wrong with Honda's 6AT, as my wife is happy to point out if I complain about the 10AT in my much newer vehicle.

OTOH we could go on for hours about 5ATs getting killed by faulty radiators or 6ATs with bad torque converters.

But I don't think it's fair to compare an AT designed to be shoehorned into a tiny space crosswise under the hood with one that takes up half the space under the car ( ZF8 ).

And I think the main problem with the 10AT is software tuning. There don't seem to be a lot of complaints about it in other applications, such as the Accord.

Funz51

Thanks. That’s an hour and 15 that I will never get back! But I did learn a lot, along with the other two links posted earlier. I once had my 88 vette trans worked on in VA beach, and they guy was blind, knew that trans really well apparently. The best guy in town. Thanks for the video.

catalytic_ca

I think this might play a role in the hesitation. With the limited torque headroom, Honda may have wanted to retard ignition timing and dump boost way down while downshifting to first or second and probably left an extra second delay in there just in case before restoring timing and boost.

anoop

Do we know if that number is true for the RDX? The article mentions it would need to be modified to handle AWD, so there may have been other changes that were made.

sonyfever

The torque capacity should be higher than that, judging from the numbers from Hondata tune. The 275 number came from the 10AT used by Odyssey. That unit has a different part number than RDX/Accord one.

Using Hondata as a reference is kind of sketchy, but they somehow always know how far they can push the powertrain safely...

I wish someone could go deep dive with Acura to understand the design choices that led to this awkward situation....

Wander

So you think that if Hondata is dialing the peak torque to 300+ ft-lbs that means that's gotta be within the transmission's rated capacity? I think you are giving them too much credit.

Mustachio

You guys are right.about it being a planetary gear AT. I thought I read that it was a DCT a few months ago.

wavshrdr

The lack of a DCT further hurts its responsiveness and acceleration times. Though according to someone I spoke with at Hondacura the reason they don't support any towing on the MDX Sport Hybrid is because of the DCT. Apparently they didn't think it would handle the load. That is the main reason I didn't end up buying one. I need to tow between 1,000 to 1,400 pounds and it was such a useless SUV that it couldn't even tow that little amount.

Wander

DCTs can be very efficient, especially if they forgo a torque converter, but this comes at the expense of smoothness. They were/are popular in areas of the world where manual transmissions were/are common, but they generated lots of complaints in the the land of the slushbox ( USA ).

And DCTs can shift fast, but whether a particular gear is rapidly available when you need it depends upon predictive software that pre-shifts the side of the trans that isn't currently driving the wheels. If it guesses wrong ( maybe a sudden request for a big downshift ), there will be a bit of a delay. Kinda like what we're complaining about with the 10AT.

DCTs are most effective for predictable acceleration, like 0-60 runs. Bragging points count.

JenRN44

I have the same issue with my RDX and I freaking hate it!!! I've brought it back to the dealer twice for the same issue and they can't find anything wrong with it. It's so frustrating! I have almost gotten into an accident a couple of times because of the stupid hesitation. I've had the car for 5 months now and want to get rid of it!!!. The dealer is willing to buy it back but I'm going to lose a lot of money so it looks like I'm stuck with a vehicle that I ABSOLUTELY HATE!!! Anyone know if this could qualify as a lemon?

anoop

Are you able to reproduce the problem in your drives? If so, were you able to demonstrate it to the shop foreman?

If you're not able to reproduce the problem and they are not able to find anything wrong with the car, you'd likely need some legal help with getting it classified as a lemon. You could start by reporting the issue to the NHTSA at:
https://www-odi.nhtsa.dot.gov/VehicleComplaint/

Ultimately if you don't like the car and/or you think it's jeopardizing your safety (and possibly the safety of others on the road), then it's better to get rid of the car even if it ends up setting you back a few thousand.

blexann

do the 2020's do this?

wavshrdr

From what I can tell, they all effn do it. I have been able to actually quantify the amount of hesitation based on testing. It is a least it takes about .6 seconds (if you totally mash the throttle) to get to 5 mph from a dead stop. I can't think of a slower car I've driven in recent memory

I drive a different rental car every week. I've been testing every Corolla, Soul, Rio, Camry, etc. that I rent now. No other car have I tested so far (Kia's, Hyundai's and Toyota's approach the slothfulness of the RDX in the 0-5 mph (off the line) sprint. Pretty depressing when a Kia Rio we'll almost beat you through the intersection without even trying hard.

Mikel P

Anyone with half a common sense brain would stay the feck away from a 10 speed turbo. What y'all thinking that a brand new nanny controlled car would be? Should've stayed with something tried tested and true, enjoy your loss on untested technology, dumbass suckers

Mikel P

V6 6 speed for the win, don't expect nothing less, vote with your wallet

Midnight Mystery

Turbo lag is real. Even on our 5AT 2007 RDX, there can be a significant lag at times. It's just how it is. There are some mods can improve it, from what I hear.

russianDude

The car has been performing very good for me and did not notice any hesitation.
10sp tranny is not new to rdx, was used in accord few years before

Dereileak

Why do we allow posts like this on the forum, putting down and slandering everyone who got this car in an explicit way, you still in high school?.. mike do you even have an RDX or plan on buying one, why are you even on these forums? I for one love my RDX, no car is perfect, I’d change some stuff for a GEN 4 but it’s the best car I have ever owned.

and the 10spd has been used for several years in the accord and odyssey, sure they could tighten up the programming for some of these hesitation issues, but overall the 10spd matches well with the 2.0t

FrankZZR

I’m lucky. This is the wife’s daily driver and I only drive it occasionally. I find the hesitation HUGE compared to my other vehicles. I find it dangerous and could not live with it if it were my daily driver. On a few occasions on a left turn with an oncoming vehicle approaching I’ve had to reapply the brakes and not continue with the turn because of the delay. Unacceptable and dangerous!

russianDude

I am driving in a sport mode 2020 sh-awd, and have not experienced any issues with hesitation described here.

wavshrdr

This is way beyond turbo lag. In general the RDX builds boost pretty quickly. Not to mention, with the super low first gear, it shouldn't need any boost to get out of its own way; To use my grandfather's jargon, "first is a granny gear".

Let's take the numbers I've been able to determine from repeated testing and put in a real life scenario. Assuming you foor it you are looking at least a 1/2 second before the engine really is allowed to get full throttle. So if you pull out on a road and the traffic is doing 60 mph, that car is already at least 44's closer before the RDX accelerates with any real earnest. This isn't turbo lag as it appears some nanny is in place to protect something somewhere. If I am coasting, at 10 mph, and mash the throttle, my acceleration is almost instantaneous by comparison.

If the condition was purely lag, it would manifest itself in the second scenario as well. While we may not get full boost immediately in the 2nd scenario we do get meaningful boost and enough to push the RDX along with urgency until the turbo is fully spooled up.

I tried to reduce the granularity of this testing. I'll break it down even further. There is some delay as the ECU get the command, I can't easily qunttify that yet but trying to do with video. It is there in all cars that are drive by wire and not usually significant. From the time the engine receives the message for full steam ahead and then accelerates to 5 mph, it is between .5 to .7 second. Then to go from 5 mph to 10 mph takes only about .2 seconds. From then on the RDX is pulling pretty well.

As I've posted in another thread, the 0-60 time vs the 5-60 mph time is much slower. Normally that is reversed for many turbo AWD cars if you are going for max performance like at the track. I looked up some times for a car I used to have, a WRX and 0-60 with a good launch was under 5 seconds. From 5-60 it was over 6 seconds. On the RDX 0-60 is at least .6 seconds slower than from 5-60 as you can't launch the car hard as some nanny prevents you from building any boost while stopped.

Setup your instrument panel to show the boost circle. To prove it on your car there is a simple experiment you can try but I am not responsible if you do. Do it in a safe area with obstructions around. Doesn't matter what drive mode either. Put the RDX in drive. Apply the brake firmly as to the floor practically. Now press the throttle to the floor. What will happen on every RDX I've tried is it will maybe get to 2k rpm and stop there. No boost will every be applied as you will never see the red boost circle. I've ran logs on this and it never gets to positive boost as something in the ECU stops it.

In most turbo cars, with automatic trans, you will build boost while setting. Let off the brake and it would slingshot you off the line. With the RDX, no such action. It takes off like a sloth after a night of partying and drinking way to much. Then at 5 mph or so, it finally wakes up and by 10 mph it is ready to party again. It transforms from the sloth to maybe a faster hare but clearly not a cheetah.

IF I am rolling, it will normally respond pretty quickly unless it has to drop a bunch of gears. Even then it is pretty good. Driving a Ktuner tuned one ramps up the fun quite a bit.

Mikel P

[QUOTE=Dereileak;16494846]Why do we allow posts like this on the forum"

That's the sentiment of many mechanics I know, but you could only imagine that their choice of words were quite more harsh. Hopefully a software update will prevent the next Mack truck from kissing your behind while merging, best of luck

Wander

Mechanics don't determine manufacturing schedules or future product development. In fact, they don't determine anything. They get paid to fix cars.

The V6/6AT combo isn't coming back, for better or worse. And good luck finding a clean one on the used market. There is probably a decent supply of vehicles that have problems with the torque converter and/or flakey VCM, if you want to deal with that.

I have yet to drive a perfect car, and I don't expect to anytime soon.

spinedoc777

It's not turbo lag.

mike232232

so the hesitation is real and it is present in all RDXs. Some people notice it and others don't. I just took my RDX to the dealer for the leaking moonroof warranty repair and they gave me 2019 MDX to drive with V6 and 9 speed transmission. The MDX although old technology drives much smoother with no hesitation whatsoever and it is definitely quicker off the line comparing to the RDX but like others have mentioned RDX makes up for the difference once the speed reaches about 10 mph, MDX is quick off the line and becomes sluggish after, RDX is slow off the line and then just jumps at certain point. MDX instrument cluster is just outdated and seats not as comfortable comparing to RDX, so no car is ideal. Having said that, I test drove XC60 prior to getting RDX and engine responsiveness is much nicer, overall in my opinion much better ride but wasn't going to spend additional 15K for the same features,

As the old saying goes, you get what you pay for...

Smilin_Jim

Wow, an intelligent response. Impressive. Good job WavShrdr

not2envy

if im not mistaken, the mdx is not turbo charged...it's Naturally aspirated...this would be the reason that there was no hesitation...

anoop

Which variant of the XC60?

flames9

I have a 2019 XC60 T8 (same motor as T6 ad plug in re-chargeable) Inscription. The T5 engine is nice but bland,I would guess he was referencing the T6. T6 inscription (top line) is around $55 with air suspension. T8 with federal and soem State rebates brings it down to almost same price as T6

Wander

A new MDX will also have the ZF 9-speed AT, which has its own issues, but Honda/Acura has had several more years to fine tune the software.

Unless it’s a sport hybrid, which has a DCT and a bunch of electric motors, but that’s a different beast altogether.

mike232232

it was the middle engine, I don't remember naming at this point but not the lowest HP engine and not the top of the line electric hybrid, middle of the line...

sonyfever

I really believe Acura has refined the setup on 2020. My car is 2019, but after some firmware updates, it drives better in all aspects. The delay is still there, but throttle response is improved in both Comfort and Sport modes, so at least the car feels more responsive.