I don't recall hearing about any differences in the engines in any Vehicross. Isuzu says that all Vehicri got the same engine before it was modified-
If you look up part numbers for the pistons and piston rings, the same pistons and rings were used in all Vehicross engines. If ya look up the Trooper engine, there's new part numbers for the pistons and rings starting in 2002.
I've been around from the start and I don't believe these engines were known to use much oil early on. Many owners did not see excessive oil use till 50-80K miles. I noticed mine at ~65K. I remember posts about the oil issue and I posted about how mine was not affected yet at Club VMag. Then it showed up later. The 99's have the most complaints 'cuz they've been around longer with more miles on 'em. Not all blown engines were low oil related. For those with low miles and no oil issues, keep a close eye on it. It may show up at any time now.
Mark