What size you looking at mate. I am in a similar position but I have 18's
2012 V6 255 55 R18 Pirelli Scorpion Verde just gone 27,000KM and they are down to the markers, doesn't seem like far enough to me but I bought the car at 16,000km so dont know the use prior, i think most was towing caravan. Mine is daily drive, mainly bitumen and some towing caravan.
Wifey has an AUDI Q5 and I just put Pirellis Scorpion Verde on that so I hope they wear better for her. cheers
Seeing you are towing a large caravan I would be looking for a Light Truck (LT) tyre for the benefit of the stiffer sidewall and higher air pressure capability which helps to run cooler.
I'm currently on the Hankook Dynapro MTR in LT 245-70/17, done over 17K so far with about half that with caravan attached, tyre wear is less than 2mm, they come with 12.8mm tread depth.
Generally a good low cost tyre, with good grip on and offroad wet or dry retains sidewall height when you air down however the thing I don't like about them is they tend to want to follow ruts in the road surface (especially on dirt) because of the square shoulders, bit off putting at first as you need to be assertive to get them out.
I don't know if this is the norm for all LT's as these are the first set I have put on any vehicle.
My thoughts now is that when it comes time for replacement I will be looking for an LT with rounded shoulders.
I put a set of Continental ContiCrossContact ATs on my 2007 vehicle two years ago - 265/65/R17 112 T. They are slightly oversize compared to the original Pirelli Scorpion 255/60/R17s (by a couple of cm), but have improved the ground clearance by that amount and also corrected the speedo to be dead accurate (using GPS).
I've done over 30k km on them and they still look only about half worn. I had a full-size spare wheel so bought five and rotate three of them through the rear wheels every few thou km (the rears seem to wear faster than the front ones on my Treg). Most of the mileage has been bitumen , incl a lot of highway work, and they are only slightly noisier than the more road-friendly Scorpions but still handle extremely well (and have a pretty good 'T' speed rating).
The couple of times I've had them off bitumen they have felt quite secure, and have well defined lugs around the shoulders. At the time, I paid about $280 per tyre but I think they may be a bit cheaper now.
I have the original Pirelli Verde on 21" rims and at 22k they are over half their life. I think they will need replacement around 35k or less.
I also do a fair bit of towing with 20 foot caravan. The performance of these tyres is good - little road noise and good grip, however their lifespan lets them down. When replacement time does come around I am thinking the Michelin Latitude will be my best option. Never had Michelin before but regularly see good reports on them.
In my opinion I think a lot is up to the driver. At 28000km my Scorpions still have about 10000km in them maybe a little more. A mate with a Q7 replaced the same tyre at 25000km and they were well and truly worn out. Another mate wore out his Contis at 20000km on a ML350. Both do far less towing than I do maybe it has something to do with running tem at a higher pressure. Who knows
Have purchased a 2012 V6TDI (second hand from dealer) Front tyres were new Coopers, rear also Coopers but almost worn out (just roadworthy) I replaced the rear with Cooper Discovery 18" wheels for approx. $310 each fitted and balanced. I am very happy with them as they are nice and quiet. Unlike my previous 2009 model which had Federal tyres fitted and sounded like mud + snow tyres. FWIW. My 100 series Landcruiser went through 2 sets of Michelin Latitude's and about 70K's a set. Extremely quiet and good performers. Would of gone with them again but was hard to obtain. So much for mismatched size tyres on a vehicle from a VW dealership.