Cruise Control

[mitch]

What's the consensus on using cruise control when towing? I think I know that generally I should stay away from overdrive but what about using cruise control in the stretches where the trans isn't hunting for a gear and going is relatively flat?

Mitch

[charliem]

[quote source="/post/1760/thread" timestamp="1404215682" author="@mitch"]What's the consensus on using cruise control when towing? I think I know that generally I should stay away from overdrive but what about using cruise control in the stretches where the trans isn't hunting for a gear and going is relatively flat?

Mitch[/quote]My two cents worth: You are correct to stay away from overdrive. It really adds to transmission heat buildup. On my 2013 Tacoma 4.0L 5 speed auto with an engine supercharger I tow in 4th gear. On long relatively flat stretches I use the cruise control with no problem. However, on roller coaster roads I turn off the cruise because the Tacoma has a particular known fault. It tends to downshift very quickly on hills, sometimes downshifting two gears immediately, then overshoots the desired speed before settling back to the set speed. The jerky result, accompanied by the whine of the supercharger, is annoying. I find I can more closely control the engine speed manually and the supercharger doesn't wind up as much. This is a Tacoma unique problem that I didn't have with my Honda Pilot. So the bottom line: do what you're comfortable with. Watch you transmission fluid temperature gauge and let it be your guide. 

[djsamuel]

I agree with what Charlie says.  If you put the cruise on, pay attention to how often the transmission is shifting.  Put the truck in tow mode as well if you have that.  If there is a lot of shifting, then I would turn it off.  Changes in grade will cause the shifting as will something that normally wouldn't, such as widely varying headwinds.

[mitch]

Thanks guys, I have the same Tacoma as you Charlie but no supercharger. I monitor the AT Oil temp using a Dashdaq connected to the ODB port. The Dashdaq has the Toyota codes in it so I can pick anything in the ECM to monitor and although the list shows 2 AT oil temp gauges they always read exactly the same value. The highest I've ever had the AT oil temp is about 230 for a very brief time but I'm always a bit paranoid about tran health when towung.

[charliem]

[quote source="/post/1765/thread" timestamp="1404219352" author="@mitch"]Thanks guys, I have the same Tacoma as you Charlie but no supercharger. I monitor the AT Oil temp using a Dashdaq connected to the ODB port. The Dashdaq has the Toyota codes in it so I can pick anything in the ECM to monitor and although the list shows 2 AT oil temp gauges they always read exactly the same value. The highest I've ever had the AT oil temp is about 230 for a very brief time but I'm always a bit paranoid about tran health when towung.[/quote][font face="arial" size="3"]Sounds like you're doing it right, Mitch. I use ScanGauge to monitor AT temp. I was aware that two temps are available, but my research never really detailed the difference. One report said one responded more quickly, but I don't remember which one. Mine responds very quickly, leading me to believe it's in [/font][font face="arial" size="3"]a flow stream somewhere vs the pan. Either way the degradation to the AT fluid is a Temp vs Time product function so short bursts will not be a problem. Some sites say the fluid is degraded by exposures to 260+ degrees, but who knows. But if the dash over-temp light comes on you're probably in trouble.

I put the SC on the Taco as insurance for my high altitude mountain climbing trips to Colorado. The jury is still out on the SC, but it does seem to work well at lower elevations. Just unexpectedly noisy.
[/font]