Thor Motor Coach 18G Promaster keeps an estimated 59% of its value after 5 years — #2333 of 5948 RVs & trailers VINdown tracks. See its full depreciation curve, cost per day, and best model year to buy.
Per VINdown's modeling, the Thor Motor Coach 18G Promaster retains an estimated 59% of its value after five years, ranking #2333 of 5948 RVs & trailers we track. That trails the 72% five-year average for Class B in its class by 13 points, so it depreciates faster than most rivals.
Most of the loss lands early: the Thor Motor Coach 18G Promaster sheds about 28% of its value in year one alone. From roughly $135,100 it falls to around $79,573 by year five — a five-year loss near $55,527, about $30.43 a day in depreciation.
Because the steepest drop hits around year 1, a lightly-used Thor Motor Coach 18G Promaster bought at 1 year old lets the first owner absorb the worst of the depreciation while the curve flattens — usually the value sweet spot. Explore the full year-by-year curve, trims, and true cost of ownership in the Model Lab above.
It keeps an estimated about 59% of its value after five years — better than most among the 5948 RVs & trailers VINdown tracks (ranked #2333).
From about $135,100 it drops to roughly $79,573 after five years — a loss near $55,527 (59% retained).
Around 1 year old: that is just past the steepest depreciation, so you skip the biggest drop while the value curve is flattening.
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