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Is engine braking -in an automatic transmission using the sport shift function- at all bad for a transmission? I only allow the rpms to get to 3(000?) when using the sport shift going downhill to make braking easier.
It's what the manual recommends to save wear and tear on the brake pads but I'm just wondering if the act of downshifting itself into a lower gear produces friction/heat/damage to the transmission or clutch do automatics even have a clutch?
I don't even know if there's a difference between an engine and a transmission, know very little about cars in general
Do you downshift to (1) slow the car down or (2) prevent it from speeding up?
1) When you downshift the revs go up and car slows as if you're stepping on the brakes.
2) Downshift before you start going down hill and just coast down the hill without gaining too much speed.
I wouldn't suggest routinely doing option 1 since brake pads are a much cheaper wear item. Option 2 is perfectly fine though. Think of it this way: an engine/transmission accelerates a 3-4000 lb car daily. Coasting downhill in gear is practically letting it take a breather!
I only downshift when going down long inclines and don't want to rely heavily on the brakes. So it's both to slow the car down and keep it from speeding up depending on how fast I want to go downhill
Ok so there is wear and tear on the transmission when engine braking, but is it any more than if I were accelerating going up a hill? I think it feel much safer and controlled to engine brake
I only downshift when going down long inclines and don't want to rely heavily on the brakes. So it's both to slow the car down and keep it from speeding up depending on how fast I want to go downhill
Ok so there is wear and tear on the transmission when engine braking, but is it any more than if I were accelerating going up a hill? I think it feel much safer and controlled to engine brake
Engine braking is perfectly acceptable in that circumstance, as long as you don't rev too high. 3K is not too high.
In my Ridgeline, Honda implemented so called grade Logic, which automatically downshifts transmission on downgrade. Sort of sucks, actually, as it has tendency to over downshift on straight also.
Honda Grade Logic Control technology is designed to hold the vehicle in a lower gear when climbing or descending a steep grade for improved performance. The transmission features an expanded complement of smart logic controls. A computer-controlled lock-up torque converter is provided to maximize fuel economy. Torque-converter lock-up and shift timing are both managed by a CPU working in cooperation with the engine's central processing unit. An over-running clutch is provided for first gear to smooth upshift quality. A direct-control strategy is used to provide real-time pressure management of the transmission's clutches. Various control strategies are utilized to allow for smooth coordination of engine and transmission operations. For example, the driveline shock that often accompanies gear changes is minimized by momentarily reducing engine torque during shifting. To reduce gear "hunting" and unnecessary shifting, Grade Logic Control is integrated into the shift programming of the transmission. Grade Logic Control alters the five-speed automatic's shift schedule, reducing shift frequency while traveling uphill or downhill. Using inputs monitoring throttle position, vehicle speed and acceleration/deceleration, Grade Logic compares the operating parameters with a digital map stored in the transmission computer. When the system determines the Odyssey is on a hill, the shift schedule is adjusted to automatically hold the transmission in a lower gear for better climbing power or increased downhill engine braking.
I use the engine braking quite often on my Pontiac Vibe since it is an automatic, but I really prefer a manual transmission for the precise gear control it provides. When taking a long curve, where I need to accelerate at the end of it to merge into traffic, I shift down to 4 or even 3 so it slows the car down, and then I'm in the lower gear already so I can accelerate quicker at the end of the curve. I really wish it had a manual, but I had to compromise for the family on this car. At least manually shifting it provides a slight improvement over a regular slushbox.
I am changing the trans fluid on a "severe service" schedule just to help keep the trans in good shape hopefully.
In my family's Prius Plug In, I use engine braking (B on the transmission) in conjunction with electric mode to send the energy going downhill directly to the battery.
On a recent two-day trip to Adirondack State Park, I forgot to bring the lock for the charger and didn't want to risk leaving the $1000 charging cable unattended. So I conserved battery power by using it only in low speed situations and charging it with braking/engine braking whenever I could. Given the many hill roads around the park, I was able to charge the battery from a low of 3.0 miles of range up to 10.0+ miles of range.
Of course, by not being able to use the battery as much as I wanted to for each day, this came at cost of fuel economy (the computer showed an overall mpg of 52 mpg for that trip, whereas I was able to average ~59 mpg on another road trip in which I was able to charge everyday and use up the battery).
Engine braking can be used for a long time on a long downhill slope, but brakes can't - they will heat up and can fail with heavy loads (that happens more so with trucks and heavy loads).
Best to let engine braking take the bulk of the braking load.
Is engine braking -in an automatic transmission using the sport shift function- at all bad for a transmission? I only allow the rpms to get to 3(000?) when using the sport shift going downhill to make braking easier.
It's what the manual recommends to save wear and tear on the brake pads...
Think about it, if it was bad for the transmission would they recommend doing it in writing and possibly risk having to perform warranty work on a damaged trans?
I downshift all the time to slow down, just gotta make sure you don't over rev the engine.
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