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BoaterAl
09-03-2010, 09:55 AM
Are there any forum Allison transmission opinions on driving on normal or punching the Allison mode button for economy?
AL

Jon Wehrenberg
09-03-2010, 12:26 PM
I don't know if we have ever had any in depth discussions, but I do believe there are times when performance is the better choice.

Most if not all our buses have economy as the default mode. Using the economy mode upshifts are at lower RPM's and shifts are smoother. The transmission will also hang in gear longer before downshifting. Most of the time by a significant percentage I am OK with the economy mode.

But I have learned that there are times when performance mode (press the mode button and "mode" shows upon the display) works better. Those times are when I am typically in hilly or rolling country. Using performance and manually selecting 5th gear allows me to maintain speed better, rather than lugging the engine before a downshift, and then losing all ability to climb the hill. By using 5th, keeping the revs up, and performance mode so the transmission downshifts sooner and upshifts later I can more easily maintain the posted speed. The downside is the harsher shifts.

When we encountered long steep hills such as out west, I used performance as well as manual downshifts a lot to not only more easily control and maintain speed, but also to manage transmission temps because I made considerable use of the retarder, but limited transmission temps to 230 on the downhill runs.

Economy goes out the window when running in the hills. The best thing I have found is drive the bus like I have to to maintain the proper speeds because you cannot run economically anyway.

Ray Davis
09-03-2010, 01:00 PM
I've tried performance mode in hills, and in smaller hills it seems to work pretty good. Unfortunately in some places it gets way too aggressive, shifting much more often than I like.

Now, I tend to keep it in economy, but I drive the selection of gears myself. I downshift early to keep revs where I want them. That tends to work better for me.

Ray

nrhareiner
09-03-2010, 02:33 PM
On our buses the red light means you are in performance mode. Some plastic coaches set it up opposite. My decision on what mode to use depends on the topography and the traffic. In extreme situations (Colorado etc) I choice the gear manually.

Kenneth Brewer
09-03-2010, 02:42 PM
I've tried performance mode in hills, and in smaller hills it seems to work pretty good. Unfortunately in some places it gets way too aggressive, shifting much more often than I like.

Now, I tend to keep it in economy, but I drive the selection of gears myself. I downshift early to keep revs where I want them. That tends to work better for me.

Ray

I too use it in the steeper hills with quite satisfactory results, and turn it off as soon I reach the more normal hills because otherwise it gets too busy, and also seems to react to the retarder when the retarder is used in conjunction with cruise control.

GDeen
09-03-2010, 03:22 PM
I like to use performance in stop and go traffic and particularly when trying to accelerate onto a freeway on ramp. Seems to get the bus moving much quicker by not short shifting as much. I am like Ray and Ken though - on some of the longer hills it can tend to hunt so I just let it be in those situations.

Kevin Erion
09-03-2010, 09:38 PM
I always leave the trany in economy mode and shift with the buttons when needed. I like to drive and this keeps the RPM where I want it, you just have to pay attention and don't forget where you are and which way to go with the buttons!