Trick for P&G On an automatic.. Hint, you need Cruise Control

[imzjustplayin]

I think I discovered the answer for those who would like to do pulse and glide on an automatic. While I have not tried this on any other cars thus far, I believe it will certainly work with Toyotas equipped with cruise control. I have an automatic, actually at the moment, all the cars I have are automatics. One problem is, if you wanted to do Pulse and Glide, you have to shift into neutral in order to coast which is fine but to shift BACK into drive while you're still moving WILL damage the transmission, for an automatic at least. Now if you tried to do the Pulse and Glide with out turning off the engine and just letting off the gas, you'll end up with engine braking which is BAD because that prevents you from GLIDING.

I noticed something when I have cruise control enabled and I catch a slope. For me, at 55mph the tach reads around 1500rpm, that is what it takes in order for it to maintain speed on the highway due to gearing of the transmission, fair enough. So I have cruise control set at 55mph and I catch a slope, now the car is accelerating to 60mph, but if I watch the tach, something happens. Instead of the RPMS increasing in line with the higher speeds which would lead to engine braking and the quick slow down to 55mph, something else happens. Since an automatic can engage and disengage the transmission at any time with degrees of engagement in between, what I'm about to tell you make makes perfect sense. So what I see are the RPMs drop to 1200, then 1000 and I think at one point 800. This means that the transmission goes into neutral when the car accelerates faster than the set speed of the cruise control and when the throttle isn't used, i.e. when coasting down a hill. I'm sure it does this in order to prolong your coast and for you to enjoy the extra speed you're picking up by coasting down the hill.

This is great news, when I'm going faster than my set cruise controlled speed, the transmission goes into neutral in order to not cause engine braking which means it won't hurt my coasting at the higher speed. Ok so how can this help a hypermiler who wants to glide for long as possible while at the same time not damage their automatic transmission? Well.... since noticing this while I'm driving on the highway, before I get off I disengage the cruise control and try to coast for as long as I can. Unfortunately if I disengage it too quickly, I'll slow down so quickly and will end up having to speed up temporarily. The reason I'd slow down faster than I'd want to is because of the engine braking that normally occurs when your foot is off the throttle and cruise control isn't enabled.

If you look at the cruise control knob on a Toyota, you'll see three arrows, one pointing up, one down and one outward. The up means "accelerate" and the down means "decelerate" and outward meaning cancel. One tip people have mentioned is using cruise control to accelerate at a very moderate pace in order to save fuel. Well cruise control can come in handy for another thing, for when you want to GLIDE. Gliding is a problem on an automatic unless you have no respect for your transmission or all your routes are down hill on at least 5% grade because of engine braking.

So when I discovered that the transmission disengages when the car goes faster than the set speed of cruise control so that you will coast while at the higher speeds, I figured I'd try something else. Instead of canceling the cruise control right before I got off the highway in order to coast, I instead held the cruise control knob downward in order to keep telling the cruise control to "decelerate", meaning to reduce my set cruise control speed. What this did was effectively do the same thing as when I had the cruise control set to 55mph and the car accelerates to 60mph due to other forces besides the throttle such as being on an incline. So by telling the cruise control to decelerate, the transmission basically goes into neutral and I was then able to glide a much farther distance since there was no engine braking.

Summary: Pulse and Glide doesn't work with an automatic unless you have no respect for your drivetrain. You can shift out of gear while moving but to shift back on an automatic while moving WILL destroy your transmission. You can't easily glide on an automatic because you will have some sort of engine braking somewhere except in one case. If you're going 55mph, have cruise control enabled and then hold "decelerate" on the cruise control continuously, the car will not use engine braking. It will not use engine braking because in this specific scenario the transmission will self disengage and effectively be in neutral, therefore permitting an actual glide.

I have found this only to be true on one car which is a Lexus, but the cruise control functions similarly on all toyotas. I plan to test this on my other cars when given the chance and I believe they will all peform the same due to them acting the same in similar circumstances. I do not know if this will work for you but there is no harm in trying. I would not be surprised if this was limited to only new toyota based cars and that were made in the last 5 years.