Mondeo - tyre life

I purchased a new Mondeo estate 3 1/2 years ago and after 12,000 miles the tyres were shot, all four Of them, continental run flat brand. I went to Kiki fit and they replaced them with marangoni which have done another 18,000 miles with a estimated 2000-3000 life remaining.

I do approx 3000 miles towing a year and 4000 solo. I wonder how this compares with other outfits.

before I retired I had a company vehicle doing 30,000 miles per year and as i remember tyres lasted approx 25000 miles. 

I always keep on top of tyre pressures and consider i do not drive like a boy racer, what at 65 yrs old!

Has anyone any figures or thoughts on this, based on :- towing vehicle, balance of towing to solo miles and makes of tyre etc.