cvt paddle downshift to aid stop?
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I downshift with the paddles only on long downhill slopes or aggressive stops. The paddles are right there and easily accessible.
Why on aggressive stops? Let the brake pedal and ABS do its job in those situations. Unless you feel like you are going to have to get on the gas real quickly soon after or during the stop - then it make sense.
2011 Outback 2.5i Premium, CVT, Steel Silver, all-weather package. Upgrades: Tweeter kit, BlueConnect, media hub, remote start, Curt 2" receiver hitch.
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Why? Because engine braking ADDS to the power of the hydraulic braking system, but does NOT pose a lockup risk.
LOL at all the people who think engine braking is bad for the engine. Do you all shift into neutral before letting your foot off the gas?
In a panic stop, the brakes are not an issue - tire traction is. Any modern braking system has plenty of power for a panic stop. There is no need to supplement them. I never said engine braking is bad for an engine, it just adds wear if it is used all the time to slow the car instead of letting the brakes do their job. My guess is that you have never done a track day in your or another car. You will quickly learn the only reason to downshift when on the brakes is to have your car in the proper gear when exiting the corner (heel-toe shifting if you have a stick). It is not to supplement the brakes and can upset the car if the downshifts are not done at the proper time. Probably not an issue on the street, but the concept is still the same.Why? Because engine braking ADDS to the power of the hydraulic braking system, but does NOT pose a lockup risk.
LOL at all the people who think engine braking is bad for the engine. Do you all shift into neutral before letting your foot off the gas?
Not the engine that I would think would suffer the most.......Transmissions in general wear from increased friction and heat/pressure on the parts (including the clutch, in a manual trans vehicle.) If you are shifting for the purpose of stopping faster, well, I hope you are not behind me. Just sayin'.Why? Because engine braking ADDS to the power of the hydraulic braking system, but does NOT pose a lockup risk.
LOL at all the people who think engine braking is bad for the engine. Do you all shift into neutral before letting your foot off the gas?
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Well the answers have ranged from absolutely - absolutely not with some insults to boot. I really don't know what to "decide", but like someone was stating they would like more proof either way.
For what it's worth, section 7-28 of the manual includes this piece under braking tips;
"Use of engine braking - Remember to make use of engine braking in addition to foot braking. When descending a grade, if only the foot brake is used, the brakes may start working improperly because of brake fluid overheating, caused by overheated brake pads. To help prevent this, shift into a lower gear to get stronger engine braking."
Against my fear of a rejected transmission warranty claim years from now (kidding), I sent a question to Subaru asking about this. I referenced what the manual states above and asked if using the cvt downshift for general stopping could cause any transmission problems or was against Subaru's intended use. I'll post the reply when I receive one.
For what it's worth, section 7-28 of the manual includes this piece under braking tips;
"Use of engine braking - Remember to make use of engine braking in addition to foot braking. When descending a grade, if only the foot brake is used, the brakes may start working improperly because of brake fluid overheating, caused by overheated brake pads. To help prevent this, shift into a lower gear to get stronger engine braking."
Against my fear of a rejected transmission warranty claim years from now (kidding), I sent a question to Subaru asking about this. I referenced what the manual states above and asked if using the cvt downshift for general stopping could cause any transmission problems or was against Subaru's intended use. I'll post the reply when I receive one.
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Down shifting and engine braking on long grades is not the same thing as down shifting through 2nd gear at every stop light on the main drag in town. TWO DIFFERENT things one being the smart and normal thing to do AKA going down a hill - the other down shifting at every light in town when it turns red is simply added wear on lots of running gear items that other wise are not providing much benefit over just using the brakes.
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Right, and I understand the additional wear side, but also think on the other side with the modern electronics governing the shifts and engine speed etc, the entire body of the car would rust out well before any tangible effects from downshifting to stop would ever show up in the cars lifetime for me at least. I'm hoping to have this car a long time which to me is 10 years / 120,000 miles.
I think I just want to hear it from the horses mouth at this point. I'm not planning to downshift every stop 100% of the time. I guess maybe if I'm coming in a little hot or light changes on me it comes in handy. Also coming from a lighter more sport oriented car (r32) so still probably adjusting my driving to the new ride. I'm anxious to hear their reply.
I think I just want to hear it from the horses mouth at this point. I'm not planning to downshift every stop 100% of the time. I guess maybe if I'm coming in a little hot or light changes on me it comes in handy. Also coming from a lighter more sport oriented car (r32) so still probably adjusting my driving to the new ride. I'm anxious to hear their reply.
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Tire traction and smooth application of braking solves your coming in hot issue - down shifting and shocking the drive lines and challenging the traction given ABS is no hooked up to your transmission. That is why in slick icy conditions you do not do harsh down shifting with an AT or MT given what little traction you might have had just got pushed over the limit by engine braking which cannot be corrected by ABS. Hit the brakes a tad hard and cause tires to skid ABS corrects the mistake.
So once again the proper way to stop fast and hard is using Brakes. You need to help keep speed CHECKED while going down a hill down shifting and using engine braking will help keep your speed down and extended use of brakes limited thus avoiding heating up brakes etc.
So once again the proper way to stop fast and hard is using Brakes. You need to help keep speed CHECKED while going down a hill down shifting and using engine braking will help keep your speed down and extended use of brakes limited thus avoiding heating up brakes etc.
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Also down shifting a car while going down a hill is generally one or two gears at most and the car is usually moving at a speed which is not a big change in engine loading when you down shift. This alone keeps the shock effect on the drive lines fairly minimal.
Down shifting many gears with the intention of loading them up with engine braking is shocking the drive lines multiple times and harder than you standard down hill down shift to keep speed checked use.
Just think about it if your down shifting to a light your intention is to get as much engine loading on the wheels as you can each down shift effectively works every joint in the drive system and when your trying to stop the car your down shifting at higher rpms for a bigger engine braking effect. Again lots of added wear not on the electrical components but on the physical joints in the drive system CV joints - drive line carriage bearing - coupler at the diff etc etc etc. Where as you could just use the brakes which have ABS to step in and manage traction if a hard stop is needed.
Down shifting many gears with the intention of loading them up with engine braking is shocking the drive lines multiple times and harder than you standard down hill down shift to keep speed checked use.
Just think about it if your down shifting to a light your intention is to get as much engine loading on the wheels as you can each down shift effectively works every joint in the drive system and when your trying to stop the car your down shifting at higher rpms for a bigger engine braking effect. Again lots of added wear not on the electrical components but on the physical joints in the drive system CV joints - drive line carriage bearing - coupler at the diff etc etc etc. Where as you could just use the brakes which have ABS to step in and manage traction if a hard stop is needed.
Same principals applied to your R32....
'18 Accord EX-L 2.0t; Wife's car: '16 3.6r Ltd. w/ Eyesight
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Doesn't that assume that the car isn't rev matching the downshifts? I'm not sure how it works in the 2.5 CVT, but I know in my GTI (and in the 3.6r), the dramatic increase to RPMs is done electronically before any load is placed on the transmission. I could be wrong, but it's worth the discussion. FWIW, if I put my car in Sport mode, the DSG pretty much downshifts to 4k RPM in every gear when coming to a stop.
Edited to add: less braking = less brake dust on your wheels!
That certainly minimizes the shock on the drive train, but still is pointless in everyday driving - except to limit brake dust.Doesn't that assume that the car isn't rev matching the downshifts? I'm not sure how it works in the 2.5 CVT, but I know in my GTI (and in the 3.6r), the dramatic increase to RPMs is done electronically before any load is placed on the transmission. I could be wrong, but it's worth the discussion. FWIW, if I put my car in Sport mode, the DSG pretty much downshifts to 4k RPM in every gear when coming to a stop.
Edited to add: less braking = less brake dust on your wheels!
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Pretty sure the CVT does not rev match it does however drop gears hard when you manually select a lower gear at a high speed =ing high engine braking loads transferred to the drive lines.
LOL, gotta love forums. You share your personal preferences, and then someone wants to crucify you for them. Each one of us paid for these vehicles on their own accord. Drive the [email protected] things as you see fit!
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I've heard a lot of 'blah blah' on this idea for years.
Of the vehicles I've had, downshifting to slow down didn't give me any unreasonable issues with durability vs not. Here's my experience to support why.
First vehicle to account for was a Plymouth Champ. That's the same as the Dodge Colt, made by Mitsubishi and sold as the Mirage. It was a front wheel drive compact. When I got it (used from in the family), it had the stock 3 speed automatic behind the 1.6L I4. I didn't bother downshifting it manually, and being a non-computer controlled automatic, it would downshift itself on longer, more drawn out decelerations. That transmission had gone out and been replaced before I got the car, and was in mega-slip mode when I rebuilt the engine @ ~100,000 miles. I looked at the other versions of the car, and found there was a 4 speed manual 'twin stick' (dual input ranges), and a plain 4 speed. The holes for mounting the hardware for a stick were all in my chassis, and the auto and stick shifters mounted in the same hole, the same way. I swapped for the plain 4 speed. I proceeded to flog it for over 125k miles and had loads of fun. I finally broke the clutch after burnouts and hard launches, and downshifting EVERY time, at that 125k mile mark. The friction material was still there, but one of the recoil springs on the friction disc finally gave out. Most people don't get that many miles out of driving a clutch 'normally', which usually means way too much slipping on 'normal' takeoffs and never downshifting. The car had no ABS, so without downshifting I had a choice of only so much braking or lockup, or the much more difficult mastery of modulating the braking myself, or adding in engine braking to compliment the regular brakes. My brakes lasted longer than normal, and make no mistake - I was (and really still am) a fairly aggressive driver.
I followed that car with an Astro van. Auto trans. Handled like a barn on wheels. Went through a trans mount, trans, U-joint, and a couple of sets of brakes in the same 125k mile span. Only engine braking used there was for long or exceptionally steep downhill grades, which was certainly less than 1k miles of that span.
ABS doesn't make your vehicle stop faster, it only maintains your ability to steer and control the vehicle. It also doesn't magically make your brakes bigger, which is the only way to make the brakes themselves really stop you faster. You're converting velocity (inertia) into heat, and it takes mass to absorb the heat, and surface area to apply friction to convert the inertia into heat. Engine braking compliments what your normal braking system does by basically bypassing it and directing some of that friction to the tires vs the road, and the rotating masses against the air being compressed in the engine. Oh, and if you think ABS wasn't designed and tested in situations where the engine was braking because of the gear it is in, you assume poorly. What do you think happens when people are still accelerating and need to perform a panic stop? Many won't remember to press in the clutch at such a panic, they'll just punch the brakes. Ever noticed how many people stall after a REAL panic stop? You can bet automakers considered this situation, and ABS will still do its best even when such is the case.
Of the vehicles I've had, downshifting to slow down didn't give me any unreasonable issues with durability vs not. Here's my experience to support why.
First vehicle to account for was a Plymouth Champ. That's the same as the Dodge Colt, made by Mitsubishi and sold as the Mirage. It was a front wheel drive compact. When I got it (used from in the family), it had the stock 3 speed automatic behind the 1.6L I4. I didn't bother downshifting it manually, and being a non-computer controlled automatic, it would downshift itself on longer, more drawn out decelerations. That transmission had gone out and been replaced before I got the car, and was in mega-slip mode when I rebuilt the engine @ ~100,000 miles. I looked at the other versions of the car, and found there was a 4 speed manual 'twin stick' (dual input ranges), and a plain 4 speed. The holes for mounting the hardware for a stick were all in my chassis, and the auto and stick shifters mounted in the same hole, the same way. I swapped for the plain 4 speed. I proceeded to flog it for over 125k miles and had loads of fun. I finally broke the clutch after burnouts and hard launches, and downshifting EVERY time, at that 125k mile mark. The friction material was still there, but one of the recoil springs on the friction disc finally gave out. Most people don't get that many miles out of driving a clutch 'normally', which usually means way too much slipping on 'normal' takeoffs and never downshifting. The car had no ABS, so without downshifting I had a choice of only so much braking or lockup, or the much more difficult mastery of modulating the braking myself, or adding in engine braking to compliment the regular brakes. My brakes lasted longer than normal, and make no mistake - I was (and really still am) a fairly aggressive driver.
I followed that car with an Astro van. Auto trans. Handled like a barn on wheels. Went through a trans mount, trans, U-joint, and a couple of sets of brakes in the same 125k mile span. Only engine braking used there was for long or exceptionally steep downhill grades, which was certainly less than 1k miles of that span.
ABS doesn't make your vehicle stop faster, it only maintains your ability to steer and control the vehicle. It also doesn't magically make your brakes bigger, which is the only way to make the brakes themselves really stop you faster. You're converting velocity (inertia) into heat, and it takes mass to absorb the heat, and surface area to apply friction to convert the inertia into heat. Engine braking compliments what your normal braking system does by basically bypassing it and directing some of that friction to the tires vs the road, and the rotating masses against the air being compressed in the engine. Oh, and if you think ABS wasn't designed and tested in situations where the engine was braking because of the gear it is in, you assume poorly. What do you think happens when people are still accelerating and need to perform a panic stop? Many won't remember to press in the clutch at such a panic, they'll just punch the brakes. Ever noticed how many people stall after a REAL panic stop? You can bet automakers considered this situation, and ABS will still do its best even when such is the case.
It should not as engine and transmission remain engaged the whole time while in the regular autos there is a tiny time interval when they are disengaged when the clutch and multi plate brakes packs open up before reengaging in different mode to form the other gear. This how I rev match my Daihatsu automatic manually by pressing the throttle as much is needed to have the engine accelerate properly for smooth downshifts at speed.
Maybe so, but the fact is that in a modern automobile, tires and/or traction available are your limiting factors in a panic stop, not the size of the brakes. If you have more traction, you will stop faster - period. The brakes do not need any assistance from the engine braking. The size of your brakes typically only typically affects brake fade on a long descent or on a racetrack (if you decide to take your OB there). Again, you do not see racecar drivers downshifting to help slow the car, they only use it to be in the proper gear for coming out of the next corner.
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