CVT and Off-road

ABFoz

ABFoz

Forum Member
Joined
Mar 24, 2018
Messages
955
Location
Auckland, New Zealand
Car Year
2005
Car Model
Forester XS
Transmission
4EAT
Hi guys,

I have no experience with the CVT yet and while my SportShift 4EAT can go places, I would like to get insights from you guys about whether or not there are issues with the use of the CVT transmission with the stuff that we do.

I am asking because I just found some videos on my YouTube front page related to newer Subarus showcasing capabilities and AWD system. I found some praising the system and another which just popped up yesterday and the Outback seemed to be struggling with an axle twister.

This is one from Slovakia about the Outback: [ame="https://www.youtube.com/watch?v=qboaSX6nKqQ"]SUBARU OUTBACK 2,5i CVT - TEST - GARÁ?.TV - NEW ENG SUB - YouTube[/ame]

This is another from the US but more of a versus: [ame="https://www.youtube.com/watch?v=WjmIke01KqE"]Only One Makes It! 2018 Subaru Outback vs Jeep Cherokee vs Gold Mine Hill - YouTube[/ame]

Another from Slovakia comparing with others but the video is older: [ame="https://www.youtube.com/watch?v=qnND_lDNwUQ"]TEST Kia Sportage - Toyota RAV4 Hybrid - Subaru Forester, ENG SUBTITLES !!! - YouTube[/ame]

When the Outback went diagonal on the one from Slovakia, the wheels were spinning fast trying to gain traction but on the one from the US, the wheels just seem to be shutting off.

What are your insights?

Cheers,
 
I think the second video shows the limit of what Subaru electronics and cvt can do. In my most recent trip, Alex’s SH when it wasn’t wheel spinning would also just sit there, engine revving but nothing happening, although his car had the 4 speed auto. I expected a better showing from x mode, and when you saw the first video you would think the car would easily handle what we saw in video 2. Video 2 more closely resembled what the SH and my SG tackled on my most recent trip.

It’s hard not to draw the conclusion that x mode isn’t as good as a rear locker and dccd combination.
 
Funnily, someone just posted the second video on the OB forum.

In short: the OB on that video would do fine with momentum, TC off, and proper and/or aired down tires. It is not possible to drive an AWD like a Wrangler. Or vice-versa, I guess.

That said, Alex's video did show exactly where the limits are. They are not that low but they are very real.

And, yes, DCCD+rear locker should beat VDC with x-mode any time. Also, don't forget the low range gearbox.
 
i saw jeep vs outback video just other day and i think because they just bought outback they still dont know how to drive it . you cant drive outback like 4wd car with low gear. its different . and you need to give VDC gas and give it some time to figure it out. and in video you can make look bad any car you want too. just make one one low psi and other on high psi in tires and it will be night and day diference.
though im curious does that CVT is made more for city and not so much for off road ? some old school auto 4eat or 5eat maybe could do that better.
 
There are many times when you have to go very slowly off roading to avoid bounce and damage. Especially when you don't have a sump guard. When I first installed my rear diff locker I went too fast, and and while it was only by 3-4kmh it was enough to damage the sump guard. That's what it's there for, but it proved again that I had to crawl really slowly over difficult terrain if I want my car to survive.
 
I'm definitely with Rally on this one. I've seen the 5 yr old vid that TFL did on the outback (the one that stopped Subaru from lending them cars) and this latest vid shows not much has improved regarding offroad ability.
I think Xmode is probably best suited to snow and sand, not bumpy stuff and CVT is all about efficiency, not raw power.
 
I agree with your points. I am not a fan of intrusive electronics. They have been the norm lately, where even road-going low ground clearance crossovers would use their traction control/ABS to trick the open diffs, making them go off-road. I also think the second video is a limitation to such systems.

Interestingly, I had a very similar climb 12 days ago and was surprised that the JDM SG made it fine. A random BH Lancaster who was also there said that many modern unlocked trucks/utes encounter trouble in that specific place. His BH did not have a problem but saw some 2.5 SGs struggle.

I was wondering, though, could that Outback in the video have made it with X-mode off? I can see that the system limits power delivery to the tires so aggressively.
 
You can never be sure watching videos as to how hard they really are. I reckon my SG could get up there (video 2) no worries, but I don’t really know.
 
There are other videos that shows how x mode is doing good job on subarus. Just because someone drove it too slowlh and carefully doesnt mean nothing. But why they took 2.5 model, it looks like on steeper hills it just lacks power / torque to wheels.
 
The reason it looks like they lack power to the wheels is because they do. The vdc or x mode is reducing the power, and/or applying the brakes. That is the point. It has nothing to do with driving too slowly. If they drove faster they could hole the sump. How are the electronics going to deal with that?
 
Put simply I hate CVTs.

I am devastated you can't get a Forester with a manual gearbox and a turbo any more. That's why I still don't know of any car that suits me more than my 18 year old Foz.

Hey Subaru - I will never drive a CVT.......never!
 
Indeed. I don’t know of any street legal Forester of any age that combines on road and off road ability as well as my 14 year old poverty pack SG.
 
Yes, I agree. Furthermore, modern day cars have so many technologies/electronics included which mean more points of failure. Even the CVTs are programmed so when they had the CVT stalling issue in the US, they had to bring their Subarus to the dealer for some sort of reflashing.

Regarding the off-road capability, I found one posted by a member of subaruoutback.org:

[ame="https://www.youtube.com/watch?v=xLEyk5Y9fPo"]Subaru is smarter than you. (Disabling Subaru Traction Control, VDC, and X Mode) - YouTube[/ame]

It seems still that the system is cutting power to the wheels probably to prevent damage to the CVT? The incline on this one is easier to gauge and is much gentler than the axle-twister I had 12 days ago. The market may actually be changing in front of our eyes, from dirt lovers to mall-goers.
 
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i have similar problems on steep inclines. VDC just dont wanna give more power. and when you think that VDC is getting in your way with VDC off you just getting wheel spins and car just dig itself down. so its even worse then delicate VDC approach. its allways looks like VDC or x mode would need more power/torque / lower gearing there and it would be unstopable.
 
Having seen Dedman testing an auto SG offroad I doubt the 4eat could have got up the hill in the second video either, even if it had the locker. Auto's and CVT's just restrict the rpm at low speeds to the stall speed, about 2000rpm and that is what limits the power. Manuals with low range can easily get the rpm up higher which gives them the power. As for auto vs CVT, I think the stall speed should be the deciding factor as to which is better.



Also Subaru's Xmode is still too slow to react in those situations, meaning loss in momentum. The faster systems found in other 4wd's handle those situations better with out noticeable loss in momentum, let alone stopping.


The tyres might have been a similar diamter, but the smaller diameter rim and therefore higher profile on the Jeep is a huge advantage! Wouldn't have made a difference in this test as tyres weren't the problem, but what was the point in saying the tyres are similar?



Also strange having a Jeep and a Subaru in an old vs new test. Thought it would be an L series and an Outback or an old Jeep and a new Jeep.
 
And strange how they call jeep andbnew outback very similar cars. Well yh sure they on similar wheels, then everything else is similar like night and day lol
 
Had the same issue as the Outback this weekend. I had lack of power on a very steep incline, revving the engine and releasing the clutch pedal fast wasn't enough. I had to back up and give a bit of momentum to pass the difficulty....EJ22 and 1,59:1 vs steep incline and high elevation (1'900m) but I finally won !
 
Seeing my off-road vehicle is an SH with VDC but not CVT or X mode, I think my Forester would have made it where the Outback failed. I've negotiated steep pinches like that with traction control off and the wheels spinning without needing an unreasonable run up to do it either. If you think power and tourque are the limiting factors, why do you think the gutless 2 litre Forester made it up a slope that was steeper than the one where the 2.5 litre Outback went nowhere? Maybe the difference is between Outback and Forester. Perhaps Subaru has programmed the system on the Outback to be biased for snow where wheel spin is undesireable as their main market seems to be Colorado where snow is the main barrier to traction.
 
I don’t think it’s a power thing. It’s about what power there is either been throttled back by the ecu, and/or the brakes being applied. Add to that slippage in the cvt or torque converter and the car goes nowhere
 
Rally said:
I don’t think it’s a power thing. It’s about what power there is either been throttled back by the ecu, and/or the brakes being applied. Add to that slippage in the cvt or torque converter and the car goes nowhere
Click to expand...

It appears, from the videos in question, that the issue is more with the Outback than the Forester. It also seems that to turn off traction control completely in the Outback, you have to fiddle with the fuses. In the SH Forester, there is a button on the dash that turns traction control completely off, allowing wheel spin. Traction control on leaves the Forester with engine power being throttled to limit wheel spin as the Outback seems to have with traction control off.

There are two separate mechanisms in play. Traction control throttles the engine, reducing power to prevent wheel spin. VDC applies brakes to wheels that slip, allowing torque to go to wheels with traction. VDC alone will not result in no forward movement and no wheel spin at the same time unless the level of traction is so high that wheels won't spin and the slope is so steep that there is insufficient power to pull the vehicle up. The situation the Outback was in seems highly unlikely unless the computer is intervening to reduce power to the wheels.

I have had wheel spin on high traction steep surfaces and demonstrated a stall speed of over 3000 rpm which is well and truly sufficient to be near the peak of both torque and power I concede that where traction is variable/inconsistent, the VDC has difficulty deciding whether to apply the brakes or not and the hesitation results in loss of momentum and perhaps even a final state of confused indecision, but this seems far more evident in the Outback than the Forester.

Having also had a CVT in a Mitsubishi, hating it and vowing never to have another one, I also acknowledge that the CVT has the potential to provide reduction gearing in a way that no conventional automatic can. Perhaps somewhere down the track some Subaru owning computer whizz will come along and produce a chip/program that will turn Foresters/Outbacks with VDC and CVT into effective rock crawlers such as many of this forum's contributors are attempting on old school vehicles with old school engineering.

It is a little discouraging to me, being an owner of a post 2008 Subaru to read contributions that dismiss newer models as incompetent compared with highly, and expensively modified older models. Keep in mind that a standard SH Forester, for example, offers a significant improvement in off-road traction to a standard SG. Give us a chance and a little time and the newer vehicles are very likely to be a surprise to everyone.
 
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