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2015 Forester Premium CVT
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433 Posts
Discussion Starter #1
2015 2.5 non-turbo, ~36k on the odometer.

I prefer to use Adaptive cruise control when I am on the highway. I go up slowly to the desired speed and turn adaptive cruise on. I try no to rev beyond 2500 rpm. As and when the traffic starts moving from a slow down, the engine revs past 4K rpm for a short burst just to gain like 5-10mph. I have no idea if that is bad for the CVT. Nowadays, I disengage adaptive cruise, increase the speed slowly and turn the cruise on again, just to avoid those high revs.

What do you guys say, are those high revs bad for the CVT or should be OK as that is how Subaru designed it.
 

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2013/14 2.5i-L CVT
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798 Posts
No, it isn't bad for the CVT which is capable of handling the ~6k rpm red line without fuss, nor is it bad to rev past 2.5k, indeed it is a good idea to put your foot to the floor occasionally to help blow out carbon and other contaminates.
 

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2015 Forester Premium CVT
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433 Posts
Discussion Starter #3
Thanks. I didn't know this carbon thing. Since I got a letter from Subaru about the extended warranty, I have been extra careful.
 

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2014 Forester 2.5i CVT
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447 Posts
You don't need to baby your vehicle. 2,500 RPM is overly conservative. The CVT is constantly changing the drive ratio based on many factors. Having the engine rev to 4,000 or whatever won't harm it. It's designed for that. Won't harm the engine, either. Overhead cams came into vogue so that high RPMs were more easily obtained and sustained.

As far as the carbon thing goes, Slothman is describing what we old-timers used to call an "Italian tune-up". Back in the day, many cars, including Fiat, Alfa, etc. needed to run a lot at high RPM to keep spark plugs from fowling, keep carbon from building up on valves, etc. So after a lot of city driving, cars often would run better if you "blew it out" or an "Italian tune-up", heavy acceleration, high RPM, high speed on the highway for a few miles.

You can choose to look at the CVT extended warranty as a red flag (warning!) or a checkered flag (winning!)
 

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2019 Forester Sport
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191 Posts
I don't experience this on my '19, but my Cobalt would do this. Overly dramatic revs to reach a higher speed when i set it to +5/10mph. Don't even get me started on hills, cruise control floors it.
 

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2012 Forester X Auto
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1,926 Posts
Although high revs don't hurt the car, they will hurt your wallet, because the engine is using more fuel to try to get you up to speed as quickly as possible, and that isn't always necessary.
I don't have the ACC, but like @MoneyJohn I also disengage cruise when in conditions that require a heavy dose of throttle to maintain a set speed, like on a short, steep hill. I'd rather just lose a few MPH than burn the gas.
By using your foot instead of the cruise, it can add up to a lot better mileage over the long haul, and the downside is just that it takes a few seconds longer to get up to speed...
For the car to do it "automagically" might be more complex, but I'm surprised that cruise controls don't typically have an option to allow for a more economical method of speeding up...
Maybe it exists somewhere in an Eco mode...
Regardless, no cruise control can do as good of a job as an engaged driver, who can anticipate what is going to happen, rather than reacting to what just did happen...
 

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'17 Imp Ltd wagon CVT
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1,172 Posts
@MoneyJohndd

Regretfully, I don't have a manual to consult on your vehicle, but on mine which has the HK Nav, the way the vehicle accelerates resuming speed in ACC is a configurable option in the Nav settings.

If you have that option (consult your settings in the EyeSight manual's ACC section) just set it on a less aggressive setting.
 

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2015 Forester Premium CVT
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433 Posts
Discussion Starter #9
Your cruise control “aggressiveness” can be adjusted in the EyeSight settings menu, if you want it to respond more gently.
I would like to know where this setting is. I checked the manual and I don't find anything for non-turbo. Turbo has SI drive where it has intelligent throttle but other than that I don't find anything. This is a 2015 vehicle.
 

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2019 Forester Limited
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791 Posts
I would like to know where this setting is. I checked the manual and I don't find anything for non-turbo. Turbo has SI drive where it has intelligent throttle but other than that I don't find anything. This is a 2015 vehicle.
For the 2019, it's discussed near the end of the EyeSight manual, under the "Customizing Functions" topic. Don't ask how long it took me to find it. Subaru manuals are something else.

I looked in the same section of the 2015 manual. Appears this feature was NOT available in 2015. Sorry to have misled you.
 

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2015 Forester Premium CVT
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433 Posts
Discussion Starter #12
For the 2019, it's discussed near the end of the EyeSight manual, under the "Customizing Functions" topic. Don't ask how long it took me to find it. Subaru manuals are something else.

I looked in the same section of the 2015 manual. Appears this feature was NOT available in 2015. Sorry to have misled you.
No worries. I read the manual end to end when we got ours and played around with almost everything so I had a feel of what was there and not.
Its good though that they implemented some new stuff to yours, probably your EyeSight is newer too, 3.0 or similar.
 
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