Towing with an automatic
 

I have just purchased a 2013 V70 D5 twin turbo, automatic transmission.
I tow a caravan with a MPTLM of 1073kg.
The V70 is well within the 85% tow limit.

I am going to the South of France in the summer and am travelling on the A75 route over the mountains of the Massif Centrale.

I have towed with a 960 automatic about ten years ago on the same route. The handbook for that vehicle stated that when driving over mountainous terrain to always select L (low gear) rather than D (drive).

Reading the handbook of my present V70 it does not mention what gear to select for mountains when towing. I only have D (drive) or S (sport mode). In S I can manually change gear.

My question is; would I be safe towing over mountains in D or should I select S mode and select 3rd or 4th?

Has anyone any experience driving with a similar car over such a terrain or any advice as to the best option.

Thanks

Tom

In my opinion the ideal way to tow with an automatic is to manually select gears to keep the torque convertor locked up as much as possible. That should greatly reduce the heat built up in the gearbox.

If pulling up steep passes etc. then the lowest gear and the lightest throttle you can use to make good progress, unless for instance you can safely hold 30mph in 3rd gear or whatever it takes to lock up the TC on your car (that's what it is on my XC90 geartronic)

I totally agree that keeping the transmission TC locked up as often as is possible is the best way to help to prevent ATF temperatures rising due to TC slip and fluid friction when not in lock up.

The lock up actually occurs within the TC itself and not the main body of the transmission.

AIUI ( and I have researched it during my auto box repair about 2 years ago ) - Effectively, in lock up, the TC is not being used "in TC mode" and fluid friction within the TC is not contributing to ATF temperature increases.

This, IMO, is especially important during ascents of significant inclines when towing.

But also significant, though less so, at all times when towing and particularly when ambient temperatures are high ( hopefully ) in summer months.

I'd rather be towing with lock up in 3rd ( manually selected ) than TC mode in 4th with no lock up when ambient temperatures are high or incline loads dictate. - Even though the box itself would automatically select 4th with no lock up.

As an aside:

I recently bought one of these:

http://www.ebay.co.uk/itm/2720361588...%3AMEBIDX%3AIT

It has a remote sensor and digital readout of temperature.

I would like to use it to monitor ATF temperature ( especially when towing ). Finding an acceptable mounting housing and/or location on the dash is another matter though.
I have thought of how to locate the remote sensor to monitor the ATF.

I have tested it off the car and it appears to be working OK.

Colin

You have chosen a brilliant car to tow with....

I would second the advice already given. The reason for using "Geartronic" mode to manually select the gears is that torque converter lockup occurs in more gears and sometimes at lower speeds than in D.

On my old (2003) XC90 that is 30 mph in 3rd, 40 mph in 4th and about 55 mph in 5th. Having driven my fathers 13-plate double blow XC70 the 6-speed gearbox and software used in that is much more advanced than this with TC lockup occurring much more often. I would learn to detect when TC lockup occurs, you might not need to resort to Geartronic often, if at all, but the trick is keeping the TC locked up.

We have travelled that route with our XC60 towing a biggish caravan.

It is a spectacular road and your will love it.

However, it does have some very steep long hills (up to 5 miles) and I used the manual selection of 3rd gear quite a lot for the declines just to save the brakes. Even then the unit would gather speed quite quickly if not gently braked a little.

Overall the car just eat it all up no problem and so will yours. In fact I felt a bit of a show off as we just flew past other units with no effort at all.

Have a great time & enjoy the Millau bridge.

Cheers,

Mike

the showing off bit comes easily with a D5 powered Volvo. Ours just pulls the 1750kg up hills almost without noticing lol

I am sure that mine is actually faster up hills!!

Hi looking at getting a my15 xc60 r design se lux nav auto would you recommend getting the paddle shifts fitted retrofitted for towing .Is there any difference between geartronic and auto .

Just use your right foot. Unless its a dedicated tow car, used purely for towing, don't worry about what gearbox is "best", go with what suits your normal driving style and how you'll be using the car 98% of the time.

If that's manual, then get a manual. If its auto, get an auto.

James

For the odd bit of towing don't worry about doing much to the car to make it a towing machine. You only worry about that when towing 10,000 odd miles a year