So I remember I think Honda was the pioneer of grade logic control of automatic transmissions (please correct me if wrong) where the car would pro-actively downshift on uphills and downshift on downhills for a better driving experience. Sounds great doesn't it? It really works well in 98% of conditions but unfortunately I live in probably the 1-2% of conditions it is just a downright annoyance 2x per day.
So my complex is at the top of a hill that is probably an 8-9% grade if not more that is probably about 1/3 mile long until it dead ends into the main road. Unfortunately it is flat for probably the first 600+ feet so accelerating out is inevitable then you hit the grade and the speeds rapidly increase - but maintaining 35-40 (posted speed is 35) could be easily maintained with slight brake pressure.
I am only complaining because I have dealt with this day in and day out for 1.5 years - I would guesstimate 500+ trips up and down this particular hill since I have lived here.
Downhill:
The grade is steep enough that any brake application is an immediate call for a downshift if you are anywhere on the downhill portion, my Mercedes cars would sing along at ~3k RPM all the way down the hill if I held any brake pressure, my Jetta TDI sings along at ~2.5k RPM. Here in lies the problem - if you maintain the absolute minimum brake pressure you will be slowed down sooner than you want well before the stop sign effectively creeping up to the stop, if you let off the brake to maintain speed the engine will upshift after a few seconds sending you speeding back up, only to brake again to get another grade logic downshift then lather rinse repeat. I have found some acceptable happy mediums between both extremes but it is hard to duplicate.
Uphill:
I honestly don't know if the uphill is worse than the downhill, it is a lot more controllable. Unfortunately towards the top of the hill there are 3 entrances to other condo/apt complexes on both sides of the road before mine which are just after a blind curve that require a slight slowdown from posted speed to account for cars crossing in front. If I fly up the hill at posted speed with no regard for other drivers I can make it to the top with no downshift. Unfortunately I try to be a courteous driver and this results in RPM low enough to end up in a jarring downshift probably ~200' from where the hill crests - all 3 cars could have lugged the remainder up the hill but they don't. Ends up in jarring acceleration immediately before I need to start slowing down for my turn.
Anyhow - sorry for the long rant. I have had great luck with grade logic crossing the mountains between Atlanta and Nashville which I think is what is really meant to help with, unfortunately it is just clunky and in the way and I am trying to adapt to it for the 1/3 mile downhill/uphill stretch that activates it 2x per day for me. Funny enough it seems as though the parameters are very similar between both VW and Mercedes - they both downshift at pretty much the same exact points both up and downhill.
So my complex is at the top of a hill that is probably an 8-9% grade if not more that is probably about 1/3 mile long until it dead ends into the main road. Unfortunately it is flat for probably the first 600+ feet so accelerating out is inevitable then you hit the grade and the speeds rapidly increase - but maintaining 35-40 (posted speed is 35) could be easily maintained with slight brake pressure.
I am only complaining because I have dealt with this day in and day out for 1.5 years - I would guesstimate 500+ trips up and down this particular hill since I have lived here.
Downhill:
The grade is steep enough that any brake application is an immediate call for a downshift if you are anywhere on the downhill portion, my Mercedes cars would sing along at ~3k RPM all the way down the hill if I held any brake pressure, my Jetta TDI sings along at ~2.5k RPM. Here in lies the problem - if you maintain the absolute minimum brake pressure you will be slowed down sooner than you want well before the stop sign effectively creeping up to the stop, if you let off the brake to maintain speed the engine will upshift after a few seconds sending you speeding back up, only to brake again to get another grade logic downshift then lather rinse repeat. I have found some acceptable happy mediums between both extremes but it is hard to duplicate.
Uphill:
I honestly don't know if the uphill is worse than the downhill, it is a lot more controllable. Unfortunately towards the top of the hill there are 3 entrances to other condo/apt complexes on both sides of the road before mine which are just after a blind curve that require a slight slowdown from posted speed to account for cars crossing in front. If I fly up the hill at posted speed with no regard for other drivers I can make it to the top with no downshift. Unfortunately I try to be a courteous driver and this results in RPM low enough to end up in a jarring downshift probably ~200' from where the hill crests - all 3 cars could have lugged the remainder up the hill but they don't. Ends up in jarring acceleration immediately before I need to start slowing down for my turn.
Anyhow - sorry for the long rant. I have had great luck with grade logic crossing the mountains between Atlanta and Nashville which I think is what is really meant to help with, unfortunately it is just clunky and in the way and I am trying to adapt to it for the 1/3 mile downhill/uphill stretch that activates it 2x per day for me. Funny enough it seems as though the parameters are very similar between both VW and Mercedes - they both downshift at pretty much the same exact points both up and downhill.
