Towing In "D" versus "4th" Gear w/Tow Mode

[scubatrooper]

I hope all you guys can handle one more dumb question about towing? I bought a 2006 Nissan Titan with the 5.6 32 valve DOHC V-8 rated at 305 HP and 379 ft/lb torque a couple months ago. The truck is rated to tow 9300 lbs. as configured. I just picked up my boat out of winter storage and used this truck to tow for the first time. It was about 45 miles back to home and I had a couple questions about the tow mode and automatic transmission.<br /><br />First, the boat weighs about 4200 lbs. total (boat, trailer, fuel, toys, etc.). <br /><br />When towing with tow mode on and the gear selector in “4th” (O/D off) I’m running about 2200 rpm at 65 mph. When towing with tow mode on and the gear selector in “D” (O/D on) I’m running about 1800 rpm at 65 mph.<br /><br />The tow mode on this truck does nothing other than alter shift points for greater acceleration when towing. It seems to do that just fine. I guess my real question is, does it hurt the transmission to tow in “D” with the tow mode on if the transmission is not shifting back and forth between O/D and 4th gear? Is the 5th gear too weak to tow 4200 lbs. on the highway?<br /><br />Even on small to moderate hills the engine never down shifted while in “D” and towing the boat. I’m sure this is attributable to the 379 ft./lbs. of torque this engine produces down low in the rpm range. The transmission temperature gauge never got more than half way while towing the entire trip (it read the same as when I'm not towing).<br /><br />This is my first season towing with the Titan and I wasn’t sure about towing in “D” versus towing in “4th” with the tow mode on in both cases. I appreciate everyone’s expertise that has much more experience towing than I have. Thanks.<br /><br />Regards,<br /><br />Steve

 

[RubberFrog]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

D is fine when using the tow mode.

 

[Cruzomatic]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

The way I learned it was, as long as the truck is not 'hunting' or 'shifting' between overdrive and drive, you should be okay with towing in 'D' or with the overdrive engaged. On hilly situtations, I'd take out the 'OD' and let the truck tow in 'D' no overdrive. Remember that last drop in RPM which is about 300-400 is not a gear shift but the torque converter in the transmission locking and unlocking. That's another thing you don't want it to do is cycle between the lock and unlock mode. <br /><br />Best of luck,,,,

 

[RubberFrog]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

That's what the "tow mode" is for.

 

[Silvertip]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

Towing in overdrive is perfectly OK so long as the transmission does not up/down shift frequently. The term is "getting busy". If thats the case, get out of Overdrive until you can again cruise without the tranmission shifting or the torque converter constantly locking & unlocking. Tow mode merely raises shift points. In my view it should be set to tow mode and left there whether you are towing or not.

 

[scubatrooper]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

Thanks to all of you for some great advice and feedback. I guess towing 4200 lbs. is not that big a deal for this truck. I just wanted to make sure I wasn't going to mess up the tranny driving in "D". I have to admit, even while in D and easing into the gas peddle, the truck would just slowly go faster. Most the time it wouldn't even downshift (when easing into the gas). It would downshift properly when I stepped into it to speed up. <br /><br />Thanks again for everyone's feedback and sharing your experiences towing.<br /><br />Regards,<br /><br />Steve

 

[Silvertip]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

Just out of curiosity is your transmission a 4 speed or five speed automatic and what does the gearshift quadrant read like? Is it "P-R-N-D-2-1" or ????. The reason I ask is you may be misinterpreting Drive, 4th gear, and overdrive.

 

[roscoe]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

When in doubt, consult your owners manual.

 

[scubatrooper]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

Upinsmoke:<br /><br />My transmission is a five speed. The owners manual states "5-speed automatic transmission with Tow/Haul Mode". <br /><br />The gear shift display reads "D-4-3-2-1". The truck as a manual shift mode on the end of the gear selector lever. When I turn the manual shift function on, the truck shifts out of "D" and into "4". I believe this is turning the overdrive off. I can then manually downshift or upshift using the toggle on the end of the gear selector lever.<br /><br />I guess I thought "D" or 5th gear was the overdrive gear. Perhaps I'm wrong and "D" is an actual 5th gear and there is an overdrive (torque converter lock-up?) going on even in "D". <br /><br />Regards,<br /><br />Steve

 

[Silvertip]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

You are correct. The way you posted the question it led me to believe you were manually switching OD on or off in other gears which is impossible. Fifth gear or "D" is indeed overdrive. In fact, 4th may be slightly overdriven as well. Not sure on your truck but it is not uncommon on five, six, and seven speed automatics to have the top two gears overdriven. With your load, D will work fine if the tranny doesn't get busy. 4th will be safe selection.

 

[scubatrooper]

Re: Towing In "D" versus "4th" Gear w/Tow Mode

Upinsmoke:<br /><br />Thank you for the clarification. Since it seemed to tow just fine in "D" (not hunting back and forth) I think I'll stay in "D" with the tow mode on with a careful eye on the tranny temp gauge. If it starts downshifting frequently I will manually stick it in "4" to keep the tranny from overheating. With a tow rating of over 9000 lbs. I don't think towing my little 18 footer at 4200 lbs. will tax my truck that much. I was under the impression the 5th gear might be to weak to tow and I didn't want to tear up that gear or the rest of the transmission.<br /><br />Thanks again for all the advice. I hope you and all the other guys have a grat boating season.<br /><br />Steve