The General Motors Hydra-Matic 9TXX nine-speed automatic transmission is found in a wide variety of front-wheel-drive and AWD GM vehicles, from sedans like the Chevy Malibu to larger crossovers like the GMC Acadia.
GM 9-speed transmission
A number of GM Authority readers recently reached out with an identical question regarding this widely used nine-speed automatic transmission: when does it actually shift into ninth gear? These readers observed that their vehicles typically tend to stay within the first eight gears when they are driving, so they wanted to know why the vehicle never seems to switch into its highest gear to save fuel as it was apparently designed. We reached out to GM for an answer, and the automaker’s assistant manager for GPD and Design Communications, Chris Bonelli, was nice enough to give us the following detailed response:
“GM’s nine-speed transmission does indeed use all nine gears when it’s most efficient to do so,” Bonelli explained. “The vehicle’s control system senses the operating conditions and chooses the right gear to deliver performance and fuel economy. The control calibration is also tailored for each vehicle application and engine type. For example, on the highway in certain vehicles, optimal fuel economy may actually be achieved in eighth gear rather than ninth gear depending on vehicle speed and throttle input. Rest assured though, the ninth gear is definitely engaged when appropriate.”
So yes, the transmission does use its ninth gear in certain conditions, but not all the time.
While some owners may expect their vehicle to be in ninth gear while they are cruising on the highway, this may not necessarily be the most efficient operating method for the car, even if the revs are lower. A variety of factors can affect fuel economy on the highway, so the GM nine-speed automatic transmission is tuned with these variables in mind, which can change from vehicle to vehicle.
The GM nine-speed automatic transmission is found in the following 2021MY GM vehicles:
- Buick Enclave
- Buick Encore GX
- Buick Envision
- Cadillac XT4
- Cadillac XT5
- Cadillac XT6
- Chevy Blazer
- Chevy Malibu (with available turbo 2.0L LTG engine)
- Chevy Trailblazer
- Chevy Traverse
- GMC Acadia
- GMC Terrain
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Comments
When ford implemented this transmission for their FWD-based vehicles, they opted to remove the 9th gear entirely citing lack of practical application.
Makes you wonder how much having the 9th gear ratio impacts the lifetime fuel economy of a vehicle, it’s probably a small fraction of a mile per gallon. Similar to the dubious cost/benefit of start-stop systems.
Gotta appease the soy eaters.
Doesn’t it also start from stop in 2nd gear most the time? I thought 1st was reserved for hard off the line acceleration and uphill starts. If you look at the actual gearing, 1st gear in this transmission is something like 4.73, or equal to the new 10 speed. I’d like to see them drop the final ratio a bit, and use 1st as a “low/crawl” and make an affordable off-road crossover. If you look at off-road reviews of the new bronco sport, it’s definitely lacking in a true low gear and does a lot of slipping and skipping.
They didn’t remove the 9th gear. It’s the same physical transmission, Ford just (electronically) doesn’t use the planetary gear combination that creates 4th gear in the GM 9-speed since 2nd thru 5th are so close together. 8th in a Ford Edge vs 9th in a Chevy Blazer are the same gear ratio at .62.
Actually the 4th clutch is removed in the Ford model.
Ford already had complaints and TSBs dealing with harsh 3-4 shifts (skipping over the removed gear), so it’s not clear they know what they’re doing. In particular, the shift over the missing gear is the highest step the transmission makes.
It smells of cost cutting because they realized they could cut out a whole clutch and the associated pieces at the expense of losing 1/9 speeds.
You would at least think they would take the time to redo the ratios to smooth the jump. Or at least open up the TC clutch to smooth it out. I have probably the last truck with the GM 4speed (sold on high incentives) and its shifts as so,
1st TC open
1st TC closed (under towing)
2nd TC open
2nd TC closed
3rd TC closed
4th TC closed ,
So my 4 speed acts like a 6 speed with 2 really inefficient gears, but the shifts are super smooth (and take almost 2 seconds to happen)
Lack of practicality , so that’s why they have a 10 speed in their trucks ?
When I drive my parents XT6, it often goes into 9th gear. It’s a very smooth transmission. My parents have no complaints…
My 2018 Encore had the 6 speed. Loved it and may be one of the best trans I’ve encountered personally. I also liked the old GM 4 speed with OD in the cars like the Park Avenue, etc. I’ve now had my CT4 about 5 months and have gotten to like the 8 speed with no issues (trans wise). MPG’s seem to be quite good and no real complaints, but still see zero reason to have the 8 speed over the 6 speed. When the CT4 was in for 2 separate services, each time they gave me a brand new XT4 Sport with the 9 speed. The first one I hated and thought how much more I like my CT4, but thought maybe the strange trans things were just that car. The second XT4 was just as bad. After driving more than 500 total miles behind the wheel of the 9 speed, I’ll pass thank you.
Dan just remember you can’t have fair and experience based critiques against lowercase gm products. I’ve been saying that this transmission was lackluster ever since my experience with it in the TB. After test driving a Seltos equipped with a DCT it’s quite obvious how much better that transmission is for daily driving over the current slushbox 9txx gm is offering. Not to mention it’s backed by a 100k warranty.
Again, I honestly have no idea how lowercase gm stock is inflated soooo high, but I bet it has something to do with borderline insider trading conducted by Mary Antionette Barra and the democrat controlled house back in March. Bullish trading in a Covid inflated market. If she’s selling over $75 million in stock you should bet that lower case gm stock isn’t going to ride this high forever.
I’ve said it before and I’ll say it again Mary only cares about her personal gains, she doesn’t care about making a vehicle the U.S. market demands and deserves. There is very little consumer demand for BEVs, and lowercase gm is falling way behind or simply not offering competitive vehicles in many key segments… I foresee a rough couple years on the horizon for lowercase gm.
h4cksaw, i agree regarding Mary and gm. Losing site of customer request for vehicles. As well as red white & blue and apple pie first. Seems China has the potential of 300 million potential buyers has jumped red only first…for another thread…
I have a 9 spd in my 19 Traverse and love it. I’ve had no issues. Very smooth through the gears especially on the highway. I’ve been in the Rockies, Smokies, and the plains, and the 9 spd perfomed outstanding. I have 35k miles on the 9 spd. I personally changed the ATF at 25k and will at 25k miles increments based on the ATF color after 25k miles. Overkill…maybe…
I also have 2 4L60E 4 spds. 1 with a 3200 stall in my Camaro and level 4 upgrade, and in my 09 Colorado v8. I can’t tell the difference in shifts. Unfortunately, one has 342 and 410 gears respectively so no mileage comparison just shift and smoothness.
9 spds are getting bad press…
Glad the 9T65 is holding up well after 35k… Not really much of an accomplishment though, that’s to be expected isn’t it. I honestly have no first hand experience with that 9spd. I was referring to the light-duty 9T45 found in the TB and GX, which seemed a bit loud and unintuitive during my test drive imho. As far as the longitudinal transmissions that’s a whole other ball game.
I will point out that the pinnacle of gm engineering, the C8, is the only vehicle in the lineup the offers a DCT. Meanwhile, the Germans, Koreans, and even the old school japanese manufacturers (acura ILX) offer a DCT starting at or under $30k. Just seems like lowercase gm is way more concerned about profits than making a car people will want… which eventually could prove to be a costly mistake.
The only reason the new corvette uses a DCT from another company is that company already had a mid engine tranny designed and ready to go. As far as transmission quality, noise, torque and shift feel, the GM 10 speed is a better better tranny. Heck even the dreaded 8 speed shifts faster than the last gen Porcshe PDK, and porsche had to throw everything they had to the new PDK to catch up. I believe that the new 10 speed can shift even faster than that. Most companies that have DCT standard are just converting their manuals by throwing on a pump, solenoids and dual clutch up front. It’s cheaper for them than retooling their facilities to slush box production. I still think slush boxes are superior. They have that wonderful thing called a torque converter that multiplies torque and has makes off the line acceleration supper silky smooth. Not grabby like a DCT.
I highly doubt the only reason that gm used a DCT in the C8 was because Tremec just had them laying around. The reason gm contracted tremec to make a DCT is because it is a quicker shifting and higher performance transmission, plain and simple. Audi’s most powerful and fastest vehicle, the R8 uses a DCT. Aside from the Ford DCT issues, they seem to be very reliable, maybe more so then 8spd slush boxes 😉 Infact some DCTs do also implement a torque converter.
Audi uses DCT because it’s easier to slap on a dual clutch on a manual than retool for slush boxes, as stated above. Also, I would like to point out, the camaro ZL1 eats the R8 for breakfast with a slush box. The 8l90 also depending on which gear can shift in 100miliseonds, same as the Corvette DCT, the 10 speed even more so, as quick as 50 milliseconds under the right condition. That largely because the slush boxes are programed to start building pressure in one clutch pack before releleaving pressure in the other. Heck even the 6 speed using this feature on Corvettes and camaros shifts in 200 milliseconds, faster than most cheap DCT’s. GM’s use of temec for this transmission was a cost cutting option. Still would have been better with a mid engine slush box.
Can you point to the DCT Audi and Benz in their larger/powerful vehicles?, I’ll save you time, you can’t. It’s a reason as why the automatic is still around for smoothness and reliability.
I want a bev, and it’s called a hummer super truck which I hope to have in fall of 22. I can’t wait….
h4cksaw: GM’s stock price has a lot to do with both their research and development of the Ultium platform, the BrightDrop program along with various other developments that bode well for their future.. Along with that, the previous overall 2020 market performance was due primarily to the ‘stay-at home’ stocks; and nearly all value stocks were languishing. But in last quarter of 2020 and thru 2021 the value sectors have now outpaced the growth sectors. Also, when GM stock price was in the #30 range, several stock analysts forecasted price appreciation for GM. So there are a lot of reasons that GM stock price has appreciated.
That’s interesting, my wife’s Blazer is a 9 and it’s the smoothest shifting GM I’ve had going back to the old 4 speeds. It’s so good it put a stop to me even considering a truck without the 10 to replace my two 6’s that are both rough.
In eco mode, many automatic transmissions usually start in 2nd gear, as 1st is only intended for heavy inclines and trailers. Even with manual gearshifts, it often starts in 2nd gear, not always in 1st gear. I noticed this many years ago in a Jeep with a 9-speed ZF automatic. It was illogical to me at the beginning, but the converter can bridge this long 2nd gear well and eternal gearshifts are not good either. This is also often the case with dual clutch transmissions and the gears are slackly engaged.
Hinweis: Mit Ausnahme von illegalen Rennen können Sie immer im 1. Gang starten, bis die Polizei eintrifft oder das Fahrzeug defekt ist!
2018 Cruze Diesel uses the 9 speed. Most efficient highway speed is 94 km/ hr. Bring the vehicle up to 96 on light throttle to get the shift from 8-9 gear, then back down to 94 km/hr. Excellent transmission- just don’t try to drive it like a Ferrari because of the slow shifting while it picks a gear.
I agree, but this usually only applies to a level road and downhill. And this is logical.
Sounds like it’s designed for epa ratings which are tested in “optimal” conditions so you’ll never really use it. Kinda like the cylinder deactivation on the big v8’s even the Slightest change in road conditions or mynute incline and the system goes right back to 8 cyl so it’s not really very effective.
So my Traverse down shits when it encounters a slight incline going down the highway, it is still giving me the same gas mileage that my old 2009 Montana and my wife’s 2016 Rogue with its 4i engine that is always struggling . . . which one do you think I enjoy driving the most? When I need to accelerate the Traverse gives me the confidence I want. And that lowest gear gives me the extra grunt to get the boat of the lake. It’s all working in harmony.
Another Rogue/Traverse/boat household! (I have an Enclave, same difference) My ‘20 Enclave gets the same/better mpg as our old ‘13 Odyssey despite a lower epa rating, and is pretty darn close to the ‘20 Rogue (company car) which never gets over 30 mpg and is always struggling. I agree that the 9 spd is always in the right gear or can shift to provide the perfect amount of power. Haven’t pulled my 3000 lb boat out of the water yet but moving it out of storage and parking it on my hill the Enclave moves it effortlessly. Odyssey always struggled. Good to hear from someone who has had a positive experience doing exactly what I will be doing. – Josh
So in other words…. “sit down and shut up the computer is smarter than you are”. I don’t believe that and neither should you!
The GM 9-speed automatic transmissions are better transmissions than those from ZF and Aisin that is known. The 1st gear is only a starting gear for extremely high loads and can only be shifted manually. The 2nd to 9th gears are usually at a very low speed for regular driving in Eco mode.
From a marketing perspective, dual clutch transmissions (DCT) are sporty automated transmissions for sporty vehicles. Since the Corvette C8 with mid-engine competes against an Audi R8, Porsche 911 and Lamborghini, an 8-speed DCT from Tremec was chosen. From Tremec as a USA supplier and GM also used the 6/7 speed manual transmission currently and previously for the Power V8, LT1 to LT5 SC. ZF and Getrag are German transmission manufacturers who already supply a large number of manufacturers, including Ferrari. So GM has a unique selling proposition with the mid-engine Corvette C8 and Ford has, as far as I know, the standard drive engine with gearbox to the rear axle with the Mustang Shelby.
As we know, an automatic converter is more comfortable in daily traffic because there is no jerking. When towing a trailer and in rough terrain, any automatic converter is much better than any DCT.
At VW, Audi and Porsche, the DCT is developed and produced in-house. VWs brands with small engines use DCT with dry clutch and large engines use DCT with oil bath clutches. The DCTs with dry clutches are very bad in traffic jams and trailers are driven because the friction of the dry clutches causes very high wear. Recall the recalls by VW to the DCT with dry clutches.
It is particularly interesting that Mercedes only uses a DCT for the Transaxle GT and BMW only uses a front-wheel drive. All BMW M vehicles now have an 8-speed automatic, as it is more comfortable, cheaper and more durable (60Tmls. Oil change!).
So choosing automatic is clearly the best way to offer customers high quality in the long term.
Translate o.k.? THANKS!
My 2019 Traverse 9t65 trans shutters so bad it feels like its going to fly apart. Dealers service manager told me there is
no fix, and they all do that. I’m 68 and have never owned a non GM . But I think this will be my last.