When Chevy announced the all-new 2018 Traverse and Buick announced the all-new 2018 Enclave, we assumed that both full-size crossovers were powered by GM’s all-new 3.6L V-6 LGX engine. But after some digging around, we realized that this is not the case. Instead, the 2018 Chevrolet Traverse and Buick Enclave are powered by a version of GM’s 3.6L V-6 LFX engine.
Assigned RPO code LFY, the motor powering the 2018 Traverse and Enclave is assigned RPO code LFY. It is essentially the same LFX engine that was ubiquitously used across many last-generation GM vehicles, but with the auto engine stop/start feature added.
In most vehicles that use a 3.6L V-6, the LFX has been superseded by the LGX — a clean-sheet high-feature V-6 engine family that improved on the LFX in every way, including power, refinement, and efficiency. So, why does it even matter? For a few reasons.
Why It Matters
First, the LFY is only slightly less powerful than the LGX. Second, the LFX does not represent the latest and greatest in GM V-6 engine engineering. Meanwhile, other vehicles that share the C1 platform with the new Traverse and Enclave — specifically the second-generation 2017 GMC Acadia and 2017 Cadillac XT5 — are powered by the LGX motor, not the LFY.
| Vehicle | Engine | Generation | Overview / Features | Power hp / kW @ RPM | Torque lb-ft / Nm @ RPM |
|---|---|---|---|---|---|
| 2018 Chevrolet Traverse | 3.6L V-6 LFY | HFV6 Gen 1+ | DOHC, SIDI, VVT, Auto Stop/Start | 305 / 228 @ 6800 | 260 / 353 @ 2800 |
| 2018 Buick Enclave | 3.6L V-6 LFY | HFV6 Gen 1+ | DOHC, SIDI, VVT, Auto Stop/Start | 305 / 228 @ 6800 | 260 / 353 @ 2800 |
| 2017 GMC Acadia | 3.6L V-6 LGX | HFV6 Gen 2 | DOHC, SIDI, VVT, Auto Stop/Start | 310 / 231.1 @ 6600 | 271 / 365.9 @ 5000 |
| 2017 Cadillac XT5 | 3.6L V-6 LGX | HFV6 Gen 2 | DOHC, SIDI, VVT, Auto Stop/Start | 310 / 231.1 @ 6600 | 271 / 365.9 @ 5000 |
Terminology
- DOHC – Dual Overhead Cam engine configuration
- SIDI – Spark Ignition Direct Injection
- VVT – Variable Valve Timing
- HFV6 – High Feature V-6 engine, GM’s internal designation for modern V-6 engines with SIDE and VVT
Generations
- Gen 1 – first generation of GM’s HFV6 engine family, the 3.6L V-6 LLT
- Gen 1+ – improvement/update to GM’s Gen 1 LLT HFV6 engine family, the 3.6L V-6 LFX. It introduced integrated exhaust manifolds and intake valves and a little larger diameter. The LFY is a further improvement on this design, introducing engine auto stop/start
- Gen 2 – all-new, second-generation of GM’s HFV6 engine family, the 3.6L V-6 LGX
The GM Authority Take
In all, GM’s choice not to include the latest 3.6L V-6 LGX engine in the 2018 Traverse and Enclave is interesting. Chances are that the decision was made to maximize per-vehicle profit, since the LFX motor delivers similar performance (at least on paper) at the LGX, while likely being much less expensive to produce, as it has been in production at the GM St. Catharines powertrain plant in Ontario, Canada for years. As such, its tooling has already been paid off.
Where a difference between the new LGX and last-gen LFX/LFY can be noticed is not on paper, but rather in refinement and noise, vibration, and harshness (NVH) levels, areas that are (unfortunately) unappreciated by the average car buyer, as they are not easy to quanitfy. In our opinion, differentiating between the GM’s new and old six-bangers takes a skilled driver on the level of an enthusiast — something that most Traverse and Enclave buyers are (likely) not. Therefore, they probably will never notice nor appreciate an awesome engine like the LGX, especially given that it likely costs GM more to produce it compared to the LFX/LFY.
Some Parting Trivia
Interestingly, GM has a history of stuffing last-generation engines into its family haulers. The first-generation Traverse, Enclave, and Acadia were introduced with the LLT first-generation HFV6 engine. When the automaker introduced the LFX as an update to the LLT, the trio never got it, instead soldering on with the LLT for their entire lifecycle.
Further Information & Reporting
Vehicles
- 2017 GMC Acadia info
- 2017 Cadillac XT5 info
- 2018 Chevrolet Traverse info
- 2018 Buick Enclave info
Engines
- GM Gen 1/Gen 1+ HFV6 family
- 3.6L V-6 LLT engine info (Gen 1)
- 3.6L V-6 LFX engine info (Gen 1+)
- 3.6L V-6 LFY engine info (Gen 1+)
- GM Gen 2 HFV6 family
- 3.6L V-6 LGX engine info
- 3.6L V-6 LGW engine info
- 3.6L V-6 LGZ engine info
Comments
This is not good. The LGX is designed as a stop/start engine, not the previous engine. This will not be great for reliability. GM can afford it for Colorado, but not Traverse/Enclave?? This is an old gm thing to do. Leave the old v6 in the past or give it us without stop/start nonsense.
Replying to your comment for better visibility (mine is about 15 threads down as of now); and you are right to bring up the start-stop, LFX/LLT/LY7’s were not designed with that in mind, one clue to look a little closer:
NOT TRUE: While they may use engine code LFY, they are part of the 2nd gen LGX family – see the specs listed on Chevy’s Media site. The bore/stroke and displacement all match the LGX family, not the LFX/LLT/LY7. The power and torque specs are listed as estimates, likely to be uprated at introduction. PLEASE CORRECT THE ARTICLE!
I will say that after seeing many reviews and test driving the Traverse myself, I would say GM hit a home run with this vehicle. It may be the best vehicle in their whole lineup.
The only reason I could see is that the peak torque moves to an even higher RPM with the LGX. That is not a good thing for drive-ability on a heavy crossover. If anything, these engines in this application need more low end torque, not more peak HP. It bugs me every time I drive my wife’s Traverse.
These are roughly 300-400 pounds lighter than the models they replace… so the power/torque argument isn’t a real factor based on much improved power/torque to weight ratios.
And ultimately, will the demo buying these notice where in the powerband the car makes peak power or torque? I’m leaning toward not.
Alex, well put on Authority Take.
Where I have an issue is utilizing this “old” engine in a vehicle as the Avenir, that will be marketed based upon luxury, sophistication, and advanced technology. How can they even consider utilizing an engine that is very similar to one introduced in 2008?
As I’ve stated before, cannot understand how they could be utilizing this engine in a vehicle that will probably be in the $55K to $65K range. Acceleration figures by Buick are 7.2–7.5 to 60. This is not much better than a Cruze! Any knowledgeable buyer that researchs the product will likely move on to one of the competitors.
Sadly I see a lot of the old GM still remains.
This is disappointing and unacceptable. However, a 0-60 of 7.2-7.5 is not only just fine for a average crossover, it’s competitive.
Not everything needs to be fast. 7.2 seconds is pretty peppy for something like this.
Most will be AWD so most 7.5. This is not even competitive with the Audis and Mercedes!
This isn’t even suppose to be comparable to merc and Audi. This is more like MDX competitor
Whether it is supposed to be a competitor is not the issue. Highly-optioned Avenirs will very likely bump into MB, Audi territory.
One direct competitor is Lincoln, and the Ecoboosts will just stomp the tired 3.6 in the Avenir!
True. But that doesn’t translate to sales for Lincoln as Enclave doesn’t outsell the Lincoln for the whole 9 yards. Avenir could be at most 60k but again Cadillac will have its own stretched version of the XT5 and competes with the MB and Audi
Traverse and Enclave are equivalent in size to the Mercedes GLE.
My local MB dealer has 7 2017 GLEs available. They range in price from $61k – $80k.
My local Chevy dealer has 10 2017 Traverse’s in stock. They range in price from $31k – $46k.
The local Buick dealer has 50 Enclaves in stock. They range in price from $38k – $47k.
Let’s add 20% to the Buick for the Avenir package. That tops the Buick out at $56k.
Buyers do NOT cross shop the German luxury brands with Buick and Chevy. It just doesn’t happen. I never considered a Buick before purchasing either Benz I have owned. I looked at BMW, Audi and Cadillac.
The Mercedes GLC (Equinox size) is $46k – $68k. Perhaps the guy looking at the base GLC may consider moving to a larger, loaded Enclave but I genuinely doubt it.
Your Buick dealer must be carrying all the cheapos. Most of the Enclaves at local Buick dealer here are in the $50s. I went on line and specd a 2017 the way I would order and it was over $55K.
You will not be getting a loaded Avenir for $56K–it will be someplace north of that, bumping into Audi and Mercedes territory.
$55k list. No one pays list for a Buick. Maybe the Grand National GNX. Certainly not for and Enclave.
I’ve had the opportunity to drive the new Traverse in its pre production form back to back with an Ecoboost explorer. Trust me when I say this, there is no comparison. The V6 in the Traverse will get up and go quite a bit better than the Ecoboost in the Ford/Lincoln.
2.7 Ecoboost in 2016 Lincoln MKX in Car & Driver test, 0-60 in 6.0. Buick’s released times for new Enclave AWD is 7.5!
But you’re comparing a 2 row MKX to a 3 row Enclave. They’re not in the same category. MKT would be the one
Two reviews I found for 3.5 Ecoboost quoted 6.1 to 60 and the other only stated a tic over 6.
Two reviews I found for 3.5 Ecoboost quoted 6.1 to 60 and the other only stated a tic over 6–for the MKT.
But then again MKT isn’t selling very stellar isn’t it?
Nor is it in the same market. No one considering the purchase of an Audi or Benz is also looking at a Chevy or Buick. Cadillac, maybe. Definitely not a Chevy.
Well it is not unusual for GM to do things like this on new models.
A lot of this may be due to supplies. Production may not be at full run? You did not say which tranny is in the vehicle as if they are using the old one too due to sort supplies could account for it.
I don’t see cost being an issue on the Buick as you do not cut corners here.
I own a LGX in my Canyon and is a good engine while MPG ratings did not change most of us are seeing about one mpg and much better drivability.
I expect as supplies grow we will see the new engine in the second year.
But if it was cost they would have never put it in the GMC Before a Buick.
Note too I have no auto stop in my application.
I thought the Canyon had the LGZ, which is an LGX tuned with more torque at a lower RPM (275 @ 4000). Given the truck specific tuning for low end torque and lower 3:42 rear gearing, I’m not sure that it can aptly be compared to the acceleration characteristics of the CUV’s in the article.
Personally, I find the high revving engines maddening when trying to merge with traffic, but if the new transmissions are calibrated correctly with quicker shifting response to throttle input, then that should help a great deal.
Actually you are correct on the code. The engines are very similar and the truck is not made for auto stop. HP is a little different per the application.
As for the high rev part forget it. The new engine has good bottom end and very good wide range power and drivability.
The greatest gain on this new engine is the drivability and the 8 speed.
No more 3000 and up only power and no throttle delays of the past.
Solid 19-20 mpg around town in a 4×4 crew.
Shocking move by GM to say the least. I honestly have no idea why you would be able to get the Acadia with the new 3.6 but not the more expensive Buick Enclave. GM still makes some head scratching decisions. Baffling to say the least. I thought GM had turned the page on small things like this. Guess not.
If they produce these vehicles for one year with the older 3.6 and then the following year they place the new engine in them, i would be one very upset customer had I purchased the vehicle a couple month earlier.
The Traverse will have the 9-speed transmission. I have driven a new 2018 at a Chevrolet salesperson training. it has plenty of power, and drives awesome!
Having also driven one at that same event i completely agree with you.
LFY engine has Start stop system. Most likely these new engines LGX weren’t up too full production yet, before these new crssovers came out. These new 9 speed automatic’s are on these new enclave and new Chevrolet transverse ,
Yes, I was confused when the 2018 Traverse/Enclave was introduced. I am still a bit confused-will the V6 in the Traverse/Enclave be the same as in the 2007-2017 GMC Acadia/Enclave/Traverse?
If so mine never, never gets over 21 unless holding at 55 mph and perhaps 13 around town (which I never use it for).
Two more questions:
1. Does anyone know if the silly Stop/Start feature can be disabled? The thought of a drunk ramming me at a light while the engine/transmission is stumbling to get moving again
2. Since GM is using a much older engine, can I assume they will NOT have AFM on it (ability to run 4 cylinders rather than 6) which has been a huge failure on GM pickups the last few years I gather. It they are not using AFM that is a HUGE plus for the old motor!!
1: You can disable stop/start but you have to do it every time you start the vehicle.
2: By 2014 GM had cylinder deactivation in the Silverado figured out. My 2012 was suffering from the oil consumption issues associated with AFM. My 2014 had no problems.
You cannot disable stop/start via a button or setting. It’s there whether you like it or not.
The only way to defeat it is to install a device which tricks the computer into thinking that the hood is open ([email protected]), or simply disconnect the hood latch sensor.
You can disable it if you put it on manual mode
Stupid argument against start/stop, While annoying and a “feature” I hope you can disable (even if that means having to do it everytime), I have never had and vehicle equipped with start/stop ‘stumble to get moving again’. And even so in your scenario the drunk was probably going to hit you one way or another. Hard to imagine that “stumbling” while restarting would make any difference.
Stupid argument against start/stop, While annoying and a “feature” I hope you can disable (even if that means having to do it everytime), I have never had any vehicle equipped with start/stop ‘stumble to get moving again’. And even so in your scenario the drunk was probably going to hit you one way or another. Hard to imagine that “stumbling” while restarting would make any difference.
I agree that the idea of a drunk hitting you and being doomed by start stop is just total foolishness.
I am not a fan of start stop and would love to have the choice of shutting it off. But having driven one again this week the system is seemless. The only aspect I can complain about is a slight shake due to the 4 cylinder start up.
As for the AFM I drive one daily and you would be had presses to make the call as to how many cylinders are in or out.
The durability at this point is not an issue.
If you have a beef with it and just honest and say you don’t like it, don’t just make crap up.
New buick enclave crossover and New Chevrolet transverse crossover both have new 9 speed automatic transmission’s.
I think a lot of people don the realize is that start stop feature doesn’t shut the engine off at all times. If the outside temp is ither too hot or cold the start stop system will not go on.
Well, the REAL Bob Lutz, the most gifted “car guy” in the last 25 years or so; ex Vice Chairman of GM; author of several books detailing the GM era of 2000-2010 when nightmares like the ORIGINAL GMC Acadia, Buick Enclave, Saturn Outlook, etc were turned into the biggest lemons since the OLDS/Pontiac Diesels, would not call concern over superfluous GM application of new technology that could be fatal as STUPID.
As he noted in “Car Guys vs. Bean Counters” and “Icons and Idiots”, GM lost control of the whole rollout of the first generation of SUVs just now being replaced with unfixable leaking sunroofs that led to major electrical failures; camshafts too short; timing chain failures, major transmission failures; necessary replacement of critical steering components, and a long list of failures for design/manufacture to live up to Marketing hype.
My concern is based on my experience of vehicles of that period and living with how really stupid “bright ideas” can sometimes be and the buyer’s need to objectively evaluate new technology, not just be naïve and accepting without proof of merit and execution. GM (and Ford for that matter) can do a great job when they set their minds to it, but proof is in the quality of the execution, and only time will tell if Stop/Start on cars will be any better than on a crude mountain golf cart.
Not sure what “lemons” you are referring to. I have owned two Traverses (2011 and 2013). I have had 0 problems with both. I still own the 2013 with about 85,000 miles.
Just curious, is there a difference in MPG between the engines?
NOT TRUE: While they may use engine code LFY, they are part of the 2nd gen LGX family – see the specs listed on Chevy’s Media site. The bore/stroke and displacement all match the LGX family, not the LFX/LLT/LY7. The power and torque specs are listed as estimates, likely to be uprated at introduction. PLEASE CORRECT THE ARTICLE!
Ummm, everyone, the 3.6L Engine in the 2017 GMC Acadia does not have Stop/Start technology. The 2.5L 4 Cylinder does, but the 6 does not get that feature. It’s also paired to a 6-speed Automatic unlike the XT5 and the upcoming Traverse/Enclave that get more gears.
Old GM shows up again !
People are complaining about what engine is going in a large cuv and I ask why? Both engines that are referenced are very close in terms of power. New vs old is something 99 % of the buyers won’t care or won’t even be aware of. AND lastly taking about engines on these types of cars not having enough power is a joke. These types of vehicles are used my soccer mom’s and grocery getters and pull a small trailer. The focus should be on what’s going on inside this car not what’s under the hood!
Weird but so GM. They have a reputation for doing this sort of thing. There have been so many complaints regarding stop/start that many folks have omitted buying a car so equipped. So what does GM do? Shove it down everybody’s throat and worse not including a proper defeat switch like Jeep and most every other manufacturer does.
And why do we need 4 variations of the 3.6 engine with 20 differing states of tune? If it were up to me the Chevy would have the 305/275 torque version of the LGX and the more costly Buick would have the 335/285 rated higher output motor as used in the Camaro and certain Cadillac sedans. You should be getting more than woodgrain, chrome, fancier interior and a different badge for 10 grand extra!
As other stated, it’s a volume issue. There are engine production lines that need to be converted and it takes time. Also, if there were a recall or supplier issue on the all-new LGX, GM would be exposed with no engines at all.
You’ve got to be kidding me. I was strongly considering the new 2018 Enclave to replace my 2009 Enclave, but not if it has a non-defeatable “stop/start”. I do not want the stupid “start/stop” feature. I do not want my engine shutting off at a stop light. People who pay $50,000 or more for a vehicle do not care about the minuscule amount of gas that would be saved by this feature.
Manual mode is your best friend dude! That’s one way to defeat it
That’s not a serious option for me, lol. I have wound the engine up pretty good a few times when I forgot that I had mine in that mode.
I did this afternoon drive a 2017 Acadia Denali. Not bad, but I don’t think it has the ride or road isolation of the Enclave, even my 2009, possibly because the Acadia Denali wore lower profile tires than the 2017 Enclave Premier parked next to it. I think the Acadia tires were 235 ratio, while the Enclave tires were 255, which means a taller sidewall and more flex.
Also, things are just a bit less spacious in the Acadia. Even though it is supposed to be 700 pounds lighter, it did not seem to have noticeably “snappier” acceleration than mine. And I do think, with its new 9-speed transmission the 2018 Enclave might actually have lower gearing in the lower gears and end up being peppier from 0 to 40mph or so. I’ll definitely wait until the new Enclave is released and check it out.
I honestly just put the transmission in manual mode for my 2016 since i tend to get better mileage when putting in manual mode
It is disappointing that about a month after this article appeared, a long Google search for specific GM details on the new stop/start system reveals no Engineering facts, only GM marketing hype to support the forced inclusion of this “feature”.
If it indeed can be disabled, manually or otherwise, great. However no GM discussion appears anywhere to support this as a production fact. Yes, I do hate the concept this type of potentially riskier addition being forced down the GM customer’s throat for little or no gain (again there is not one shred of GM Engineering data to support the inclusion of Stop/Start as a fuel saving technique. By the XXXX increase in starter cycle over the life of the vehicle means a huge increase in vehicle maintenance costs way, way less than any few drops of fuel saved).
As too with the AFM, if they have finally got it working without GM’s previous generations’ oil consumption and maintenance costs, swell. However GM needs to talk in public about what is better technically with the new AFM system than their previous generation of failures, and quit letting the marketing department do the engineering departments’ explaining.
Thanks for doing the Google search. IMO, there is no way enough fuel can be saved to offset the cost of a starter replacement, and my suspicion is that this start/stop stuff is mostly a way to appear more PC and appeal to people worried about climate change. I was initially just aggravated with not being able to defeat it, but I didn’t even think about how many additional times the starter would be engaged.
I take it your not too bright! In some ways maybe your just stuck in your old ways but saying would sound like a compliment. This is something that I don’t think you deserve.
You don’t like start stop technology? Let me guess you didn’t like disc brakes, A/C, P/S, Fuel injection, MRC, I could go on but I think people get the point!,
Just because you don’t like it doesn’t mean GM shouldn’t produce them. GM is forcing it down your throat, GM is forced to do this in order to meet regulations in the future.
This type of technology is here to stay so you and your not on my lawn type of people better get use to it because every car built in the near future will have some sort of fuel saving technology.
So it’s time for you to put on your big boy pants and stop acting like a two year old! Be a adult and realize that the world is changing and you are going to be apart of it weather you like it or not!
GM doesn’t make cars for you and you alone, this makes you seem very argonaut. That cars have to be built to your specifications or the car is a failure. Who are you to decide what the rest of the world gets?
These fuel saving systems that GM uses from start stop, DoD, VVT, hybrid ect ect ect! I don’t need a report to know that these systems that are used save fuel a little bit at a time. I should know I own one of them. Works great!
This seems to me like more of a control issue on your part then anything else. Which is not a very good reason to dislike it!
I wish I could say more but it would just get me into trouble!