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I am towing a GeoPro FBS with a factory weight of 3300 lbs and tongue weight of 415lbs; my question is the impact on the Ascent transmission while traveling through mountains. while trvling up hill on a highway my gas mileage dropped to 13 MPG and rpms were up to 3000; am i over stressing the car with this setup?
 

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Watch your wet tongue weight, and follow Subaru's guidance not to exceed 45 mph while going up long grades and you shouldn't have a problem.
 

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I recommend using an OBD-II application such as ActiveOBD to monitor your temperatures. This will give you instant and continuous feedback as to whether you're stressing the engine and transmission.

See this thread for more details.
 

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rpms were up to 3000
The beauty of the CVT is there are no fixed gears, so, RPMs will be wherever the computer thinks is best. I wouldn't use the paddle shifters to override the computer's choice when under towing load, and I wouldn't worry about 3,000 rpm. That's normal, and helps with cooling and preventing engine lugging. Also don't worry if the RPMs vary up and down. No fixed gears means the computer can vary the RPM's infinitely to find the best RPMs for the conditions.
 

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Right. Nothing wrong with 3000 rpm on a small engine. Power is torque times RPM, so lower RPM can put more stress on the engine for a given power output. Higher RPM can mean more coolant flow and oil flow through the cooling systems. I figure the engineers that programmed the ECU and TCU and extensively tested the vehicle in extreme conditions know better than I do (except maybe for the marketing driven inclusion of faux shifting).
 

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....follow Subaru's guidance not to exceed 45 mph while going up long grades and you shouldn't have a problem.
Thank you for this tidbit of info. I haven't read (or can't remember (just as likely 😂)) that. I've towed a handful of longer grades now and noticed that the car was working a bit too hard to keep it at the Adaptive Cruise Control I had set (55mph), so my intuition was to just take it slower, which was 45 and what I do now and it feels a lot better. No issues at all towing up grades.
 

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Thank you for this tidbit of info. I haven't read (or can't remember (just as likely 😂)) that. I've towed a handful of longer grades now and noticed that the car was working a bit too hard to keep it at the Adaptive Cruise Control I had set (55mph), so my intuition was to just take it slower, which was 45 and what I do now and it feels a lot better. No issues at all towing up grades.
I've always been told not to engage cruise control when towing. This is to prevent traditional automatic transmissions from "hunting" for ideal gear ratios when climbing hills. However my belief is that this is a non-issue for CVTs, especially our modern TR690s which are installed in vehicles marketed for towing.

The majority of my travels are on flat terrain so I do engage ACC for the duration of my towing trips. Once I encounter significant hills, I disable ACC to prevent overzealous/unnecessary acceleration and strain. I'm fine dropping to 50mph on long climbs and staying at 3k rpm instead of maintaining 60mph at 4k rpm as the ACC wants to do.
 

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When towing with other vehicles they can have a "tow mode". The vehicle can be a completely different animal when that is engaged. Shifting will change, RPMs will change, engine breaking will kick in, anti-sway logic ... all sorts of stuff happens ... for the better. As others have recommended change your fluids at the extreme use intervals if you tow a lot. The Ascent has a built in tow mode that appears to engage on its own. I say trust it. About the biggest thing to watch is your transmission temperature.

Prior experience with vehicles with gears in the mountains ... gear hunting ... high RPMs ... low RPMs ... jerked one way then the other. It was all par for the experience to get to the higher elevation. When you don't know any other way it is just "normal".

While I have never towed with a CVT in the mountains I have driven in the mountains with one ('18 Outback 2.5). Boy oh boy ... it is amazing. It was the smoothest experience I have ever had in the mountains. My wife even drove for some of it. She has a tendency to have a heavy foot. It smoothed her out quite nicely.

Oh ... expecting fuel efficiency while towing ... you are in for a rude awakening. Get that out of your head fast. I would say expect 10 mpg plus or minus 2 mpg. If you get more then that - bonus. Of course this depends on what you are towing. At the end of the day though, if you are pulling the same weight as your vehicle, your gas mileage is going to drop.
 

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I have driven in the mountains with one ('18 Outback 2.5). Boy oh boy ... it is amazing. It was the smoothest experience I have ever had in the mountains.
Second this! The 2.5l in the '13 OB was a little anemic at elevation, but the CVT was as smooth as buttahhh.

I did tow a small 8' moving trailer with the OB. In LA and OC traffic. And up the grade from the beach into Calabasas. It was slow, but intentionally so. That CVT handled it quite well.
 

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That's correct. The Ascent's EyeSight manual states not to use ACC when towing.
I read this as just a warning that the system may not work as intended. Is there something in the manual that says not to use ACC when towing? I don't see an issue with it as long as conditions are optimal e.g. good weather, visibility, no traffic, etc.

Oh ... expecting fuel efficiency while towing ... you are in for a rude awakening. Get that out of your head fast. I would say expect 10 mpg plus or minus 2 mpg. If you get more then that - bonus. Of course this depends on what you are towing. At the end of the day though, if you are pulling the same weight as your vehicle, your gas mileage is going to drop.
Agreed. I routinely get 31mpg highway and barely get to 12mpg when towing my Jayco X18D (dry weight 3,410lbs) with three humans and two dogs. The real issue becomes range. My largest fill-up was around 15 gallons so that makes for a conservative range of 180 miles when towing at or near the Ascents upper limits.
 
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