Downshifting a CVT

subaru
impreza

#1

My Subaru Impreza has levers on the column to downshift and upshift. I’ve been using the downshift to slow the car and reduce wear on the brakes. However, I thought I remembered you guys saying brakes were cheaper than a transmission. So is this a good idea, or should i just use the brakes?


#2

For some reason I’d rather downshift. I like to be able to control speed with just the accelerator and NOT be dancing back and forth, pedal to pedal. For me it’s about better and smoother vehicle control and I’ve never seen a transmission issue from doing it this way.
There will be lots of opinions both ways here.

My wife’s 06 Escape hybrid CVT has an L ‘‘low’’ selection after D. In this case it creates a slow down resistance but does not affect driving speeds. We both drive in this mode all the time.


#3

Not a problem with a regular geared AT or a manual transmission for that matter. CVTs are an unknown at this time. They are just now going mainstream after a rocky start, and only in 4 cylinder vehicles, the more powerful V6 models still use the traditional ATs.

My instincts say to drive a CVT very conservatively because they don’t seem to be as strong as a geared AT, but on the other hand, they shift constantly. They hold the engine at a constant RPM while making slight changes to the gear ratios for going up and down hills. I would use the manual position for downshifting on a long steep downhill, especially one with curves, but otherwise leave it alone.

I have just bought a new Subaru Legacy with the CVT and the paddle shifters. I don’t like the paddle shifters at all. This is not a race car and to use the paddle shifters, you have to move the gear shift lever over to the manual position. If you find yourself heading into a downhill curve and want to downshift, you have to take your hand off the steering wheel and move the shifter. By that time you are turning the wheel and the paddle is now out of reach. Never had a problem with this using a manual transmission but it requires too many movements with the paddle shifters.

I though I might use the paddle shifters to force the transmission to upshift earlier, more like the driving pattern I use with a manual, but again, it is more awkward to use. If you are accelerating from a right or left had turn after a stop, the paddles are out of reach when you want to make the first upshift. So much easier to just move the stick.

And to top it all off, paddle shifters that are almost completely useless on a street car to imply racer combined with an electric parking brake, come on. How do you drift with an electric parking brake? What is Subaru thinking. But overall I love the car.


#4

+1 for @keith. I have never understood why someone would use the drivetrain to slow down a vehicle. Brakes are cheaper than transmissions and they were designed for that very purpose. As long as I’m not footing the bill…anyone can drive as they please. I would think that an anchor and chain could be used to slow down a vehicle as well but, for me, I’m using with my brake pedal to slow down or stop.


#5

I agree with Keith in that it’s probably wise to choose a conservative approach when using any technology such as a CVT that has yet to really develop a known history. To my mind that means not using the tranny to slow down.

But, then, I never was much of a risk taker.


#6

IMHO, the OP should definitely downshift on steep downgrades, in order to prevent the brakes from overheating. However, except for that type of situation, you should rely on your brakes, rather than playing with the transmission.


#7

There are CVTs on V6 cars these days (see Nissan). My Honda CVT will downshift with the paddle with no shift lever action needed. It goes back to “normal” at the next throttle application.


#8

I have usually said that brakes are cheaper than transmissions but brakes seem to be catching up a little. Your concern shows that you can probably keep both of them going.


#9

I notice that my cousins Altima with CVT will downshift on its own if she brakes when going downhill.


#10

Correction, I had tried to see what would happen if I pulled on the paddles in drive while the car was in the driveway and nothing happened. Just for the heck of it, I pulled on the downshift paddle while slowing down to a stop and it did go into manual and downshifted, I downshifted one more gear, but it would not upshift with the stick in the drive position. I had to move the stick into manual and back to drive to get it back into drive.

Its nice to know that it will do this. Most of the time I will use the brakes, but there are some mountains out west where just for safety, I will downshift. My life is worth more than the cost of a transmission and I would trust the brakes to work all the way to the bottom.


#11

I have a Crosstrek with the CVT. My experience is that using the brakes, for the most part, is the way to slow and stop. I use the manual function from time to time but generally when I am in snow and slippery conditions or I am trying to maintain a specific speed on a road rally and I want the revs to be in the higher torque range. Otherwise just keep it in drive and use the brakes. Brake repairs are a LOT cheaper than transmission repairs. For what it is worth, Subaru is offering this same CVT in more powerful cars in 2014 and 2015 so I think it is built in typical Subaru fashion, solid.


#12

This is another one of those " all or nothing questions" that get disagreement that if the supposition were made in another way, both sides would be right. It is recomended in manuals I have read that down shifting an automatic ( even CVTs) or a standard is RECOMENDED instead of sustained braking. It is also recomended that you " down shift" in areas that would induce hunting to control speed. Situations like 35 mph areas with lots of traffic lights or driving in and out every day over a dirt road with steep areas and long steep hills in general with easily exceeded posted speed limits with coasting alone, all encourage down shifting.

This type of downshifting is done to control speed and not just for stopping. Today’s autos are meant to help control speed and keep brake usage at reasonable levels. To never use paddle shifters or the shift mode as in my cars has is not what the manufacturer had intended. Today’s transmissions are not only safe to use to controlled speed, they are made for it. It’s a matter of degree and the car manuals spell it out. Everyone I hope can agree that doesn’t violate, “would you rather use brake pads or buy a new transmission” philosophy. No one recomends you downshift every time you want to stop but anyone would be foolish not to take advantage of a built in speed control device, like the motor via the transmission.


#13

So Guys,the CVT comes of age?-Kevin(I’m still a bit unsure)


#14

Kev., I look at it this way. Subaru is still rated to tow 2700 lbs and major players Toyota, Honda, Nissan and Subaru use them. They have arrived. Of course if I didn’t think these cars with them are as reliable as those other cars without, I would have to eliminate a lot of top quality cars from from my list of perspectives.


#15

What Toyota?


#16

#17

Friction drive CVT slips even when staying in a constant ratio. When the pulleys are turning, the belt or chain is going straight. Therefore, part of the pulley would have a different linear velocity than the chain or belt. Since it is constantly slipping, I downshifting would cause extra wear to the transmission.


#18

Thanks Dag,-Kevin


#19

Thanks for all the advice. I find that the CVT does not slow the car much when you take your foot off the accelerator - it coasts really well. I sometimes end up going faster than I expect as i approach a stop. So I tend to use the paddles plus the brakes. I also use the paddle on curves to slow down a bit. But I do understand the CVT is relatively new. It’s why I asked the question. And brakes can be expensive - it’s why I got rid of the Mazda Protege5 that was costing me $500 a year in brake repairs. Sticky calipers.
Keith - to get it to upshift, just accelerate. No need to shift into manual. It does hesitate sometimes. And you can hit the paddle twice if you really need to slow down.


#20

“brakes can be expensive”

If you think that brakes are expensive, then–trust me–you would be VERY happy about the costs involved in replacing your transmission.

Downshifting a CVT or automatic transmission on a steep downgrade is recommended in order to avoid overheating your brakes.
Downshifting these transmissions for stop lights and curves is not recommended.

If you sometimes find that you are going too fast when you see a red light, that is probably an indication of either driving too fast, or not paying close enough attention to that traffic light as you approach it, or both.