Automatic gear-Box as a tow-car?

[JohnI.Stephen]

Am considering buying a more suitable tow car for my Bailey Senator; the Merc C250T being beyond the '85% limit' of the CC and has all sorst of other issues.....

Would really like an automatic but was warned by a serious caravaner that unless I go for a Range Rover / Disco, the gear box will fry; unless it's fitted with an oil cooler.

Question : Would the Sorento 2.5 diesel automatic be OK to tow up to its max or do you all go for manual boxes in this section of the market (mid price, mid sized cars?

Should one go for manual boxes in general?

John

 

[Lutz]

I think you'll find that everyone who has an automatic would never change back to a manual. I think that says it all.

As for additional oil coolers, it's best to check with the car dealer who should advise (best even in writing). Most cars do not need one and you may even loose warranty coverage if you have one fitted against the manufacturer's recommendation.

 

[RogerL_5041474]

Virtually all car manufacturers will state "no transmission oil cooler is necessary" because to admit that it's necessary is admission of a design fault.

Fitting an oil cooler can't invalidate the warranty UNLESS it causes damage to other components, which of course it won't!

Many manufacturers fit a transmission cooler but this is ofter a pipe running through the bottom "tank" of the water radiator. While this will help with very excessive overheating, it'll never cool the oil below 90 degrees C even if 100% efficient.

Many manufacturers include towing in their "extreme" conditions so often recommend changing the auto transmission fluid at more frequent intervals. Some, like Vauxhall, don't need a fluid change ever, unless operating in extremes like towing.

Fit an oil cooler for peace of mind and change the fluid regularly, eg annually.

 

[rob_jax]

John,

We have an automatic Merc C270 CDI, and would not go back to a manual. Driving is just so much easier and the fuel consumption is within 1 or 2 mpg of the manual box - actually better when towing because the manual version is detuned by 10% - the manual gearbox is torque limited.

Open the bonnet, and look for a black S shaped pipe in front of the radiator(s) - this should be the gearbox cooler and it should be a standard fit.

Oh - the 85% rule is just a recommendation for people new to towing, you can legally tow up to the limits in your car's documentation pack. But remember that your car or van could weigh more than the basic posted specification.

Robert

 

[Lutz]

Roger, one cannot say that fitting an automatic transmission oil cooler cannot cause damage to other components. It can. If the location of the oil cooler is such that it in any way affects the airflow in the engine compartment, which it might do if it is installed ahead of the radiator, for example, engine cooling may be adversely affected. So, what you've gained on the roundabouts you'd loose on the swings. Note that this not only applies to the cooling performance of the engine itself but also its ancillary components such as the generator. Some cars even have to have a separate blower (factory fitted) to cool the generator because it cannot be kept cool enough any other way.

 

[DavidW1]

John,

Speaking from experience of towing with auto and manual I would go for Auto from choice - it just takes all the worries about hill starts and clutch control away and makes for a very stress free operation all round.

On the point of transmission coolers it's probably the cost factor that stops makers fitting them to ordinary cars as their main purpose in life after all is not towing.

In the worst case scenario - ie. towing at MGTW in hilly country or stop start in summer traffic, your autobox is going to fry thats for sure and risk damage as a result without a proper cooler.

More expensive marques such as Jag fit them as standard and as you say Discos, as well as Shoguns and Landcruisers which have the capability to tow high loads factored into the design from the outset.

If the Sorento Auto has no cooler (which is surpising) I would personally go for manual.

 

[JohnI.Stephen]

Thanks all; to be clear though, I do WANT to go for an automatic but when talking to an expereinces CC Hire Car / Trailer owner yesterday (in Kent), and specifically as regards the Renault Espace 1.9 cdi diesel, he mentioned that no way should I consider an automatic (on that car).

For my size of 'van, (1440 kg max)he suggested that I should only tow using vehicke with an automatic box which specifically has an oil cooler; he related horrow stories about caravaners breaking down because they did not appreciate this point.

So, yes I will go for the automatic IF (and only if) they can convince me that the box won't fry. However, you all seem to feel that an autobox on a regular vehicle is OK; or perhaps you have carvan's weighing less?

 

[Lutz]

That's why renault specify a lower max. permissible Gross Train Weight for the automatic Espace, at least for the 2.2 litre diesel. I haven't got figures for a 1.9 automatic (maybe there isn't one).

 

[Lol1]

John, you can tow with an Automatic Sorento, without fear, I'm not absolutely sure but I think the car has a cooler already installed, best to check with the dealer though. I have a manual Sorento and am very happy with it, but have been told that the Auto is even better, does not loose much in performance (some say its quicker) and almost as good in the mpg department.

 

[JohnI.Stephen]

Thanks all; extremely helpful.

regards

John

 

[JohnI.Stephen]

Hello LOL :

have just speken to a large KIA dealer in Kent. They assure me that not only is the Sorrento Automatic an execellent two car but that they have used one for the past year to haul a large trailer and large vehicles from A to B. They confirm that yes, it does have an OIL cooler and that teh Auto box is superb as the box of choice for towing.

Thanks all; decision's now made

 

[Lord Braykewynde]

John, I drive a VW Passat Auto and have had no problems at all. It really is a pleasure towing with it and to echo what Lutz said "I would never go back to manual". p.s. No oil cooler.

 

[JohnI.Stephen]

John, I drive a VW Passat Auto and have had no problems at all. It really is a pleasure towing with it and to echo what Lutz said "I would never go back to manual". p.s. No oil cooler.

Noted; thanks. Makes me feel much more comfortable!

John

 

[Lol1]

Hello LOL :

have just speken to a large KIA dealer in Kent. They assure me that not only is the Sorrento Automatic an execellent two car but that they have used one for the past year to haul a large trailer and large vehicles from A to B. They confirm that yes, it does have an OIL cooler and that teh Auto box is superb as the box of choice for towing.

Thanks all; decision's now made

I really must let Kia know how many cars I'm selling for them!

Well done John, I am confident that you will enjoy the Sorento, glad we could be of help.