[subiesailor]

Down hill speed check down shift is actually a good idea especially with the CVT given its pretty slippery and the car will just rocket down hill unchecked.

Driving around town and down shifting as you approach stoplights? Brakes are a better idea cost less to service than a CVT and even the MT folks say down shifting past 3rd for regular use around town stuff is just shocking the running gear hard and adding wear to the transmission - and drive lines which really isn't worth the value add going below 3rd.

 

[subiesailor]

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.

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.

 

[subiesailor]

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.

 

[subiesailor]

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.

 

[subiesailor]

That certainly minimizes the shock on the drive train, but still is pointless in everyday driving - except to limit brake dust.

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.