Last year, no flats with Marathon Plus on my 1991 mountain bike in about 4 000 km. This year got two flats in less than a month (including a side cut that killed that tire) in the Spring with Grand Prix 4000S II tires on my 2012 Giant TCX bike. I then added Mr. Tuffy liners and no flat in the following 3 000 km. Now that we're in the Fall season, I replaced the GP with Marathon Plus on my TCX hoping to reduce my chances of having a flat in cold weather.