If you have heavy industry in your area some will no doubt use stationary engines; diesel, gasoline or natural gas. Most, if not all with 1000 hp+ engines, will monitor their engine wear by routine oil analysis. Manufacturers of these engines and even highway trucks; Caterpillar, Mack, GM, Mercedes, etc. will also know where this is done in your area. Contact a few and ask the service manager who they would recommend.