towing with auto

Glyn,
Modern automatics are generally quite robust and smart. I consider it best to just let it do what it wants, it will normally choose the right gear and obtain the best fuel economy.

The exceptions are where there are a series of corners or hills which causes the transmission to change up and down a lot. I normally force it to hold a lower gear just to reduce the load.

Heat is the killer for auto transmissions and when the weather is hot or the load is high ease off and do not stress the system. I do not know the Sorrento but I assume it has a good transmission oil cooler. If not consider having one fitted. Transmission oil is normally pink and clear. Pull the dip stick regularly and look and smell. The first sign of browning or a burnt smell indicates danger and you should have the oil changed.

I have towed using an auto a lot over the years and never had a problem. I put this down to being sensitive to how the vehicle is travelling and giving the transmission the best chance to do its work.

I rarely use the cruise control in the LC100. It tends to be too enthusiastic and accelerates too hard when the speed drops. My previous Pajero was much better in that regard. Cruise control does not have the input that your eyes give you where you can see the road ahead and know when to accelerate etc.

You will soon work out the best regime for the Sorrento, just listen and feel and it will tell you what it like and hates.

cheers
alastair

Personally I NEVER tow in 5th(OD) for the reasons described in this rather long thread

Have a read and make up your own mind


http://forum.candm.com.au/showthread.php?t=3900&page=5

As stated the cruise in a 100ser is a bit harsh and uses more fuel than just driving it.

I rarely use it except perhaps on the Nullabor or similar flat roads.

I have not started towing yet but I am surprised at how gentle the cruise control is on the rodeo. I was used to the cruise on falcons and holden sedans that kick in really hard, this just brings you back up to speed nice and easy.

I have a lead foot and tend to drift above the speed limit on long runs so cruise control is great for my driving and avoiding fines :-)

Hello Glyn,
We previously had a BL 2005 3.5lt 5-speed auto Sorento & travelled 100,000Km in it with a 1100kg camper on the back for a good 40,000km. From my experiences the vehicle tows exception well, however a slight gradient or head wind & the auto torque converter would unlock early in 5th, the side affect of this if you leave it in auto mode is the transmission temp increases dramatically. I found it much nicer to put it in manual mode & leave in 4th except for tail winds etc, this locks the torque converter. I would also advise you change your springs F&R and the front struts, it will be a much nicer more stable vehicle for towing.

Note: The auto fluid has a 90,000km service life & holds approx 10lt at approx $30per/ltr, so a oil change due to stressing the oils is costly.

These are a very under rated vehicle with a good build, the only limitation with us was a growing family & more room required.

Hope this helps.

fyi: If interested I have the Pedder coils & Koni struts from our vehicle available

regards Simon.

Generally concur with everything said here.

We had a 2001 Tribute towing a C/T from Sydney the Red Centre in 2008. Nearly cooked the engine in far west NSW using the cruise control. The cruise control is a objective device - if you set it to 100km, by hook or by crook it will go 100km. If this means 2-3 gear changes per 5 minutes then so be it.

The advice is not to drive with the cruise control and drive with the overdrive off.

Agree with most others, when towing don't use overdrive and if you must use cruise control, only when it is flat country.
CC uses extra fuel trying to stick to the set speed when it is not appropriate.
The freer revving motor in direct drive will use less fuel, be an easier drive and cause less wear and stress on motor and transmission, than will driving in overdrive..

KenD
bris

This is a quote from the Kia National Service Manager.

" One other issue is that the vehicle should be driven in auto mode whist
> towing especially uphill. The manual mode can be used for downhill and
> for overtaking. Please read the towing section in the Owners Manual that
> explains this in detail "
the reason is "When in manual mode, the transmission control unit does not allow the torque convertor lock up clutch to engage thus causing excess slippage especially when towing."

The full letter can be read here Kia Sorento Forum