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I’m John Cadogan from AutoExpert.com.au - the place where Aussie new car buyers save thousands off their next new cars. Hit me up on the website for that. autoexpert.com...
This question is from Paul.
I am thinking of buying a new Hyundai Kona Highlander 1.6T but I occasionally tow a box trailer to the local tip. Will this affect the DCT in the vehicle as I have seen your video on the different types of transmissions and how to break them?
Long story short: The most common enquiries I get about dual-clutch transmissions or DCTs - what Volkswagen calls DSGs - are about the Hyundai 1.6 turbo petrol engine in Tucson, Kona and i30 (and also the baby diesel in i30).
Hyundai DCTs seem pretty robust - I don’t get owner complaints about them.
But they can be killed if you presume your DCT is an auto transmission and therefore abuse the clutch. So let’s sort this out.
Kona is rated to tow a maximum of 1300kg (max). A box trailer to the tip will be less than half that (because Kona’s limit for unbraked trailers is 600 kilos), so Paul’s is a very conservative proposed towing assignment. And he’s not going to be doing it that often, most likely - because most people don’t have a trailer-load of used rubber adult products (or whatever) to dump each week.
What you need to watch with DCTs is riding the clutch. Obviously the clutch is automated, and the 11th Commandment - the one Moses fumbled and dropped - is ‘thou shalt not inch forward under load’ (meaning: at a speed so low it does not allow the clutch to engage properly in first or reverse).
Because if you commit the venial sin of expecting the clutch to transmit a lot of load before it fully engages, the parts will rub together hard. There’s going to be a lot of heat. And friction-based devices like clutches and brakes all have a limit to the amount of heat they can reject. And when you generate more heat than that, they die.
If you’ve driven a manual you know what I mean. Riding the clutch fills the car with that distinctive ‘barbecued clutch’ smell, at the same time as it fills your monthly budget with a black hole of mechanical accountability.
Obviously there is a (slow) speed around walking pace below which you need to start to slip the clutch or the engine will start to labour and eventually stall. With the automated clutch in the DCT, at these slow speeds the computer automatically intervenes to keep the engine from stalling by slipping the clutch. This is what you must avoid.
You can feel this easily as you drive on a DCT. It’s patently obvious when the clutch is not yet fully engaged. Especially under load.
The key-word here is 'under load'. Think: trailer-gravity-hill plus ‘slower than walking pace’ equals ‘repair bill you cannot jump over’. I’d suggest the easiest place on earth to destroy the clutch is reversing a loaded trailer (boat, caravan - whatever) up a steep, convoluted driveway.
For the clutch - this is like waking up in hospital and seeing Dr Kevorkian at the bedside. That’s never a good omen.
In my view, this vulnerability to damage is not a design defect any more than riding the clutch in a manual and killing it prematurely is a design defect. So if you kill the clutch this way, it’s not going to be a warranty job.
I do, however, think the car industry really needs to do a better job getting the word out there on this. Saying ‘it’s in the owner’s manual’ is a bit of a cop-out.
Remember that this limitation only pertains to inching forward (or in reverse) at a speed so low it does not allow the lowest gear to engage fully. You can drive normally on a DCT all day long with a trailer behind, in stop-start traffic, no problem. Normal takeoffs in traffic - hill starts, etc. - minus the trailer are also no problem. It’s not especially fragile.
I strongly advocate the use of the vehicle's 'auto hold' function to make those hill starts easier. You also need to remember that the transmission - like the rest of the car - is designed in the case of Kona for 1300kg trailer GVMs.