Thread: Towing with an 8 speed D4.

1200 revs with 2.8T??

This might explain why I see many saying they tow in sports mode which drops it downs a gear I believe. As you previously experienced my 2010 3.0L 6 speed tows brilliantly without any issue in D.

Think more about the torque a 2.7 TDV6 generates versus the torque generated by the full version of the 3.0 SDV6 & that probably explains it. The engine & box combo will work to sit in the right rev band. Just because you have 8 speeds doesn't mean you'll always be in top gear.
I would have thought your experience was normal.

Did the D4 know there was a trailer attached? (ie a current load device if your van has LED lights?) If not, the gearbox shift pattern will not adapt to the extra trailer weight. As also said, it can also be beneficial to put the shifter (knob) in Sport mode so it will downshift sooner and hold gears longer.

Thank you for your comments. The car in question is a 2016 tdv6 3litre with 520 nm. I thought that would be enough.and operate something similar to my old D4 which as mentioned tows really well. and yes the car does know that their is a trailer on the back.
I was under the impression that sport stays in the higher gears for a little longer. I tried sport mode and found it great on hilly roads ,but not much better on the freeways...
Richard.

I have towed the same weight as you for around 20k km with my TDV6. I only tow in Sport mode & mostly leave the gearbox to do its own thing. It happily trundles along in 8th at 100km/hr until there is a headwind, then 7th gear is the go. When using Cruise Control (most of the time) I tend to paddle to 6th or sometimes 5th gear when approaching a hill to prevent slowing down while Cruise Control sorts out that we have slowed & then madly accelerates to catch up. Having previously towed with D2 TD5, the D4 is in another universe when towing.

You are comparing two completely different drive trains and engines. Final drive ratios are different as well as the torque curves on the engines:

1st	4.714 (15.13)		1st	4.171 (14.77)
2nd	3.143 (10.09)		2nd	2.34 (8.28)
3rd	2.106 (6.76)		3rd	1.521 (5.38)
4th	1.667 (5.35)		4th	1.143 (4.05)
5th	1.285 (4.12)		5th	0.867 (3.07)
6th	1 (3.21)		6th	0.691 (2.45)
7th	0.839 (2.69)
8th	0.667 (2.14)
R	3.317		R	3.403
Final drive ratio std:	3.21		Final drive ratio std:	3.54

2010 3L 180KW/600NM:



2016 3L 155KW/520NM



Both engines are pretty much the same upto 1500RPM from then on the differences are obvious. combine that with the final drive ratios and you can see what is going on.

At 1200 RPM you're running at about 420NM of torque and 60KW power so add that to the tall gearing and it's no wonder the engine is labouring. Go faster to get the sweet spot or use a lower gear

Originally Posted by SBD4

2010 3L 800KW/600NM:

Special edition power version....


My 230KW 8-speed 4.4 with a slightly higher final drive ratio suffers from the same problems when it happily gets down to 1000 rpm with 2.5T behind until a slight incline.