his case study shows how Delta-Xero tested landfill gas engines, including CAT 3516, CAT 3520, Jenbacher 320 and Jenbacher 420, to prove that silicon levels alone do not accurately show how harmful the contamination really is. It uses POLARIS lab analysis and Micro Patch Ferrography to reveal abrasive wear, varnish and contamination that standard oil analysis can miss. It also shows before/after examples where Delta-Xero reduced abrasive contamination by around 98% and helped extend oil drain intervals.