Hashim bro, do you really mean it with the CNG?? Well, if I do install it, and I've not driven CNG since 2002, been on Petrol throughout with both Corolla SE Saloon and CITY 2006 IDSI, I was thinking to do so when past 10000 Odo. Yet, I got to know yesterday that Indus now offers pre-installed CNG on 0 odo!!!
Let me be clear, I've never favored CNG, and will check the fuel consumption first, if I get anything like 14-15km/l long, hence some Rs. 5.5/ km, I'm most likely to stay on with the petrol, as long as that "commodity" stands at Rs. sub 90/ltr. The CNG option, though, is a very economical thing to have for the local drive, which in my case is around 1000km/monthly, in 2.nd/3rd gear mostly.
Yet back to rpm, going Motorway tomorrow, Inshallah.
Regards.