Its not lean burn. Its very rare to find a lean burn engine. The Civic VX, HX, 1st gen Civic hybrid (manual trans), and 1st gen Insight hybrid (manual trans) were probably the most popular. Other mfgs have made lean burn variants, but nothing that works as well. I believe gascort said
his early 90s escort may have had a mild lean burn mode... All diesels run lean. Toyota has had lean burn engines, but nothing ever sold in the US. Other than that though, I'm not aware of any lean burn engines (I'm sure there are a couple, but not many). No vehicles being sold today have lean burn capability due to NOx emissions problems.