This was the case a few years back when the fastest pools were implemented with recursive data structures (e.g. linked lists for the freelists in gperftools).
In the new tcmalloc (and, I think, hoard?) the fastest pools are essentially slabs with bump allocation, so the fastest (and by far, the most common) calls are a grand total of 15 or so instructions, without many cache misses (size class lookups tend to stay in the cache). Call overhead can be a substantial chunk of that.
Not OP, but I do (a fair amount of) HPDE/TT with an m240i, converted to the cup car spec.
Running costs for me are ~$500 / 2-hour day on 100-TW tires. These cars aren't exactly light, so they eat through consumables. Tires are the largest part, then repairs, then brakes. This doesn't count fuel.
If I had to guess for OP in PWC, 50-100% more, mostly driven by slick costs.
In the new tcmalloc (and, I think, hoard?) the fastest pools are essentially slabs with bump allocation, so the fastest (and by far, the most common) calls are a grand total of 15 or so instructions, without many cache misses (size class lookups tend to stay in the cache). Call overhead can be a substantial chunk of that.