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Will the 2.4L Turbo Boxer engine be reliable in the long run?

46K views 42 replies 25 participants last post by  hokiefyd 
#1 ·
Hi Everyone

We are considering the 2021 Honda Pilot and 2021 Subaru Ascent. We were wondering how reliable the 2.4l Turbo Boxer engine will be in the long run vs say the 3.5L V6 in the Pilot? Will there be more carbon build up on the 2.4L?

Thanks
 
#4 ·
At the end of the day, I guess it really depends on how long you intend to keep vehicles. For us, our 2010 Honda Pilot was suppose to give us at least 200k. It’s a Honda right? At 110k it started acting up and before we knew it the repairs started adding up. We kept up with the service recommendations. It also had a known piston ring problem that was fixed at 60k to rear it’s ugly head again at 110k. Luckily, Honda paid for it anyway even though it was out of the drivetrain warranty. Then another thing happeded that we had to shed another 1k for. The battery holder basically disintegrated, luckily they were already fixing the 1k problem. The 2019 Ascent replaced the Pilot. Leap of faith, because of being a 1st Gen. My wife was turned off by Honda and she really didn’t like the new body style of the Pilot. I think you are good either way. Reliability for cars today is really a crapshoot. We’ve been good with our purchase so far.
 
#7 ·
The current Honda engines seem to be good. They had a tough time with them in the 2007-2012 timeframe when they were still trying to figure out their active cylinder management. Our 2005 Acura has 178k miles and our 2009 Ridgeline has 150k miles. The drivetrains are 100% original and flawless still, but neither has the active cylinder management...both have just the standard VTEC. My folks have a 2014 Acura MDX with something like 120k miles and it's been good to them so far. The engine seems solid and it seems like Honda worked out many of the kinks with their valvetrain trickery to disable cylinders by 2012-2013-ish. Theirs is also direct injected (the 2014 MDX) and that system has proven to be pretty good, at least for them. No issues to report.

On the other hand, the latest Subaru engines have been good also. The FB and FA engines have, to my knowledge, resolved the EJ engines' tendency to blow head gaskets. Those were installed in Outbacks as recently as 2012 I think. So Subaru's had some challenges with the fundamentals just like Honda has, but the FB and FA engines seem to be pretty robust. I don't worry about the turbocharger, personally. Like @Rick S WA noted, Subie's been building engines with turbos for a long time.

It's also worth noting that Subaru's getting only 260 hp and 277 lb*ft of torque out of 2.4L of displacement. Acura's RDX engine (the K20C4), achieves 272 hp and 280 lb*ft of torque from 20% less displacement (2.0L). In other words, Subaru's squeezing less power/volume out of this engine than many of their competitors are. In general, that's a good thing for durability. Also worth noting: aftermarket tuners have found the tune in the Ascent to be very conservative and have even found more fuel octane to not really increase engine performance in the stock tune. This is also a good thing for durability.
 
#15 ·
Agree with Hokiefyd’s comments ... they are very well said. I also spoke at length to a tech at COBB tuning who reiterated his comments, in that COBB had a relatively easy time bringing the 2.4’s HP and Torque up significantly with only a high octane tune. And did so without any additional bolt-ons. Having just bought a 2021 Touring I hope this to be true!
 
#10 ·
I don't think you have anything to worry about with the Subaru 2.4 T (Pretty much every manufacturer out there makes reliable turbo motors at this point). I wouldn't base your purchase decision strictly on whether the engine is NA or forced induction. If you like the ascent better, then buy it

Maybe if you were considering a Turbo versus an NA engine back in the mid eighties or nineties we'd recommend the NA engine, But nowadays it's pretty much irrelevant. All 3 of my current cars are turbocharged, and every car I've owned in the past 10 years, save for my Corvette, has been. Nowadays with turbos producing torque at such low rpms, it's almost no different than having a moderate sized V6 or V8.
 
#13 ·
I don't think you have anything to worry about with the Subaru 2.4 T (Pretty much every manufacturer out there makes reliable turbo motors at this point). I wouldn't base your purchase decision strictly on whether the engine is NA or forced induction. If you like the ascent better, then buy it

Maybe if you were considering a Turbo versus an NA engine back in the mid eighties or nineties we'd recommend the NA engine, But nowadays it's pretty much irrelevant. All 3 of my current cars are turbocharged, and every car I've owned in the past 10 years, save for my Corvette, has been. Nowadays with turbos producing [inconsistent] torque at such low rpms, it's almost no different than having a moderate sized V6 or V8.
fixed it for ya .... lol 😉 :p
 
#11 ·
I used to run screaming from turbo engines, but after reading up on the Ascent. I jumped into the small displacement turbo bandwagon. I've been completely happy with the range of power and the torque band. I had the 3.0-H6 and the 2.4 reminds me of it (except for the laggy 4 speed....). I have no doubt I will get the normal Subaru life span out of my 21 Ascent.
 
#12 ·
I'm at over 72,000 pretty brutal miles with no issues.
 
#14 ·
The only problem I've ever had with torque delivery on any turbo 4 is, at least my opinion, related to the CVT on the ascent. I get the lag, or dead spot, at low speeds (usually, but not always) going uphill when the rpms drop from 2600-3200 to ~2000-2200.

I know it's not the engine, as it's got plenty of torque, I believe it's the cvt and ecm not playing nicely. If I hold gears manually I don't get the lag, even in the 2000-2200rpm range.

My other cars, which currently are all turbo 4's with zf8 speed slushboxes (the zf is great transmission, btw) don't have that issue. Interestingly, all 3 of my cars make nearly identical peak torque at nearly the same speed. I honestly don't miss my v6, i6, t6, or ttv8's.
 
#16 ·
Consider leasing. 3 years will give you a risk free idea of what you're up against. If you like it, refinance the balance. If you don't start over. My guess is Subaru will have other engine options by then. We just got an Ascent on a 3 year lease and we have been pulling a 4K lb camper and the engine is purring with no issues.
 
#18 ·
That's my plan as well. I also just leased a 2021 Ascent Limited to use for towing a 4K lb. camper as well as an everyday driver. Who knows what improvements or new tech will come along in three years? Leasing keeps me close to the forefront of innovation and keeps me in a nice, fairly new car.
 
#19 · (Edited)
Interesting point of view ... I have always been a buyer vs a leaser, as I have not wanted to be a slave to a mileage limit. Other than that, not sure if it (leasing vs buying) really makes much difference from a financial perspective. All I know for sure is I am happy with my 2021 Touring. Love the upgraded eyesight, adaptive cruise, overall driving position/comfort.
 
#22 ·
IDK. I've read about head gasket issues on Subarus. IDK if the 2.4 is plagued with it. Once of my sister in laws has a 2011 Outback. She came to visit us from Texas and the head gaskets blew on the way here. She got it fixed here, $4400 later. I guess what I am saying is that I hope it's reliable. We've had he Ascent 2 years 4 months, 40k miles so far. No issues with it yet, at least anything major. Just recalls, maintenance and a radio unit that won't keep presets and won't connect to wifi. The original tires were done by 25k too. For me, other than not liking a CVT, it gets terrible gas mileage around town. When it was in the body shop I rented a F150 super crew with a 5.0 v8 and that got better mileage in the same usage.
 
#28 ·
I beat the snot out of my turbo on my 09 WRX and after 80k hard miles it was as good as new!

I wouldn't worry about the turbo!
 
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#34 ·
The EJ Series is quite different, in many key ways, than the FA Series. Heck, the FA24F is quite different in many key ways than the FA20. Regardless, the head gasket in my 2010 Outback finally went at about 180,000 miles of doing stupid things, like yanking cars out of the sand that were way above the car's tow rating, and, it cost me $2,200 for getting the head gaskets done, installing a new viscous coupling in the manual transmission, and replacing the clutch, water pump, pulleys, timing belt, etc. That's at Metro NY's labor rate, which is about twice some places I've visited.
 
#36 ·
On the topic of turbo reliability in Subaru, I've got a 2004 Subaru WRX Wagon that has 235k miles on it. I beat the heck out of that thing for every mile and it runs like a champ. Neither the turbo or engine has had any major failure. We had the radiator replaced at 192k miles and then the original clutch replaced at 230k miles. Literally that's all that's needed to be done to it. Just regular maintenance and drive it hard, it seems to love it. The reliability of our WRX is why we are looking at the Ascent as a replacement for our 2020 Chrysler Pacifica Hybrid minivan, which we bought about 9 months ago. 2 of those months it has spent at the dealership service (and is still there now for a new major steering issue).

On the topic of the new Ascent turbo engine specifically, Subaru is going to use that in the new STI and other vehicles, which might be why it's conservatively tuned on the Ascent.

My 1 and only concern with any new vehicle is the transmission. I'm not a fan of CVT, very much dislike the fake shifting as well. We had a 2016 Nissan Pathfinder CVT need replacing at about 30k miles...and now our 2020 Chrysler Pacifica Hybrid transmission replaced at about 6,400 miles. Both of those vehicles were driven non-aggressively (compared to how we drive the WRX).

Well, I guess my other complaint would be the low MPG rating of the Ascent. Seems most people get about 22mpg. With our plug-in hybrid van we are getting 50 to 60mpg. Our WRX gets about 24mpg (and again, we flog that thing all day!). 22mpg for a modern SUV seems almost comically low to me.
 
#37 ·
On the topic of turbo reliability in Subaru, I've got a 2004 Subaru WRX Wagon that has 235k miles on it. I beat the heck out of that thing for every mile and it runs like a champ. Neither the turbo or engine has had any major failure. We had the radiator replaced at 192k miles and then the original clutch replaced at 230k miles. Literally that's all that's needed to be done to it. Just regular maintenance and drive it hard, it seems to love it. The reliability of our WRX is why we are looking at the Ascent as a replacement for our 2020 Chrysler Pacifica Hybrid minivan, which we bought about 9 months ago. 2 of those months it has spent at the dealership service (and is still there now for a new major steering issue).

On the topic of the new Ascent turbo engine specifically, Subaru is going to use that in the new STI and other vehicles, which might be why it's conservatively tuned on the Ascent.

My 1 and only concern with any new vehicle is the transmission. I'm not a fan of CVT, very much dislike the fake shifting as well. We had a 2016 Nissan Pathfinder CVT need replacing at about 30k miles...and now our 2020 Chrysler Pacifica Hybrid transmission replaced at about 6,400 miles. Both of those vehicles were driven non-aggressively (compared to how we drive the WRX).

Well, I guess my other complaint would be the low MPG rating of the Ascent. Seems most people get about 22mpg. With our plug-in hybrid van we are getting 50 to 60mpg. Our WRX gets about 24mpg (and again, we flog that thing all day!). 22mpg for a modern SUV seems almost comically low to me.
The CVT in the Subaru's have been working great. That is not to say that some owners would prefer a different tuning, but they work as designed very well. You either like it, tolerate it or do not buy it. As far as the mileage, it is all about how you drive it. If you want to get higher mileage, it is achievable in the Ascent. Early on I got over 30MPG in my 2019 Kimited on a road trip. I also have had mid teens. Play to play is the game. If you are concerned about paying some additional money for MPG don't buy a $40,000 autmoatic vehicle of that size and weight. The 2004 WRX was rated as 18/25 and weighed 3085 lbs and was a manual transmission. A full 2/3 of what the Ascent weighs, not including the added cargo and passengers the Ascent would presumably carry.

Maybe something more like this:
13172
 
#43 ·
Another thought on this...the Ascent is rated 20/26 or 21/27 depending on trim (we believe this is due primarily to the larger wheels on the Limited and Touring). I do think this compares pretty favorably of some of its competition. The Kia/Hyundai twins are rated 19/24 regardless of options. So the Ascent is either a 5/8% gain or an 11/13% gain on those two (that's significant!). Even more impressive is a comparison against the VW Atlas, another competitor in this market. It's rated 20/24 with the 2.0L turbo or 16/22 with the 3.6L V-6 option. The Ascent really shines compared to VW in the fuel efficiency department. It outshines the Jeep Grand Cherokee AWD (rated 18/25 with the 3.6L V-6 engine) and the GM Lambda SUVs (rated 17/25). It basically matches the Toyota (rated 20/27 with the 3.5L V-6) and does a little better than the Honda (rated 19/26).

It also outshines the AWD Pacifica, even. The Pacifica is rated 17/25 in AWD form.

So to the comment about one manufacturer being able to eek out just a MPG or two over the others...I think Subaru really are doing that. I'm not sure anybody in the SUV space significantly beats Subaru in a like-for-like comparison...and the Ascent is a far more frugal choice that some of its competition for sure.
 
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