http://www.viddler.com/explore/maximumtorque/videos/2/
Logan is the mileage champion sedan. It can deliver a fuel efficiency as high as 30.36 kmpl in ideal driving conditiond. Watch the video The Mahindra Renault Logan Mileage Run

Mileage runs are supposed to be taken with a pinch of salt. Even Ford did a mileage run with thier fiesta after MR did with logan.

Result?

They showed approx 38 kmpl as the FE. So, its very subjective.

It is the day-to-day figures that we have to go by, from actual users. Not occassional test drivers

and yes the actual mileage figures for logan are not bad at all.

however mileage alone is not sufficient to keep a product alive.

In my 1.6 gls running on CNG ( lOVATO open loop kit with TAP ) , I have consistently got 25 kmpkg. plus on Mumbai Lonavala Mumbai runs in AC.
Now if you discount the ghats , rumbling strips , toll plazas and the winding roads and continue to cruise on a level concrete road with high tyre pressure & no ac I am sure FE would be around 30kmpkg.
The Logan is tuned for effeciency whether its the petrol or the 1.6 K7M motor that i have.
Its immensely drive able and smooth.
I am inclined to believe that the quoted figures may be true after all.

The Diesel may be a bit better than the CNG version.
On petrol itself i feel one would be very happy with 18kmpl let alone 30 +.

Nice mileage on CNG.