First time towing was a success. Overdrive though?

2005 Tacoma Prerunner w/ tow package (220k miles), towing a 1750lb trailer with a 2700lb track car on it. Installed a brake controller, one axle electric brake on the trailer. Roughly 500+ mile round trip from my house to the race track, almost all of it on the interstate. Very proud of this truck now!



This was my first time ever towing anything, the towing bible section on this forum was a huge help! Really glad the trailer had an electric brake, after driving with the brake turned off there is no way I would feel safe without it. Acceleration was poor, but not bad enough to where I couldnt keep up with the flow of traffic. Getting up to interstate speed wasnt bad, maintaining it was fine until I reached a decent grade uphill. I averaged about 14mpg mostly interstate driving, which is great considering i only get 16mpg going to and from work in city traffic. Overall this truck did excellent, i was very nervous at first but the truck never swayed, drifted or did anything to make me feel unsafe. On the drive home I actually felt more confident and started passing slower cars, whereas on the way there I just fell in line behind the 18 wheelers.

I do have a question about Overdrive though. I know it is mentioned never to use it due to gear hunting under load. So i was thinking if you're on a flat stretch of interstate at 70mph then why not use it? So i did end up using overdrive quite a bit, but i would always go into 4 when climbing hills or if i had to slow down. I had zero problems driving like this, my engine temp never moved and the truck drives just fine after the trip. Im guessing its OK to use overdrive as i did, only on flat stretches? Or is there something in the way the trans is designed that overdrive creates more heat when towing due to increased load? Thanks!

 

If you are towing a light load on level highway it’s probably ok to tow in D. I’ve done it without problem. However you are towing over 4000lbs. You should tow in 4 whether your tranny is hunting gears or not when pulling as much weight as you are.Your OM tells you to tow in 4. I would follow the OM in your case.

 

The tranny may not be rated for towing heavy in OD for extended periods of time. To get enough power to use D you will need to be driving very fast which causes increased chance of instability occurring, increased wind drag and reduces MPG. The water pump on your engine will also not be turning fast enough to cool effiently. Your engine may have been getting hotter than normal if you were only looking at the dummy guage on the dash. Drive your rig no faster than 65mph. 55-60 is your sweet spot in 4th gear, you will have a more comfortable tow with plenty of power and cooling aswell as improving MPGs.