Its a 98 Diesel Corolla swapped 7AFE (1800cc) petrol engine.
Ravager CNG avg are funny I mean I remember I had a 1.5 Car and on CNG it use to do 190 to 180 easily in ISB. When I swapped in 1800CC engine I was worried and I was happy to get 140KM but the car surprised me with an avg of 265 than We adjusted it more and it came down to 200 KM which is fine as it gives amazing torque on CNG.
My Mechanic who adjusted my car for this avg in his car he got 1.5L engine and with all tunning all he gets is 80 to 90KM hehe so some time you need to be lucky with CNG Avgs. Some time same car's with same engine get two totally different avg. Also depends on how you drive and traffic condition, Use of AC.
But most old toyota engines and suzuki engines are happy to run on cng.