Nissan 30 km mileage. Review on Nissan Micra

I have blue colour nissan micra dci engine . I replaced my micra's 165/70 R 14 tyres with swift tyre 165 / 80 r 14 all four tyres so mileage is actual mileage = on road mileage x swift tyre circumference 1948 mm divided by micra tyre circumference 1848 mm == on road mileage x 1.0544.

Because of swift tyre suspension very good . Initially it gave 27 kmpl on normal road and 30 kms in four lane but after 11500 kilometres it is giving 30.04 km mileage in normal road--1800 rpm sharp 75 km speed. Actual speed is [ 75 x 1.0544 ]79 km per hour because of swift tyre road grip less but very good soft suspension running like petrol car 5th gear from 41 km speed like my estilo car .

Mileage route karaikudi to coutrallam 464 kilometres up and down without ac keelavalavu to melur lot of poth holes 50 gear changes f0r 15 kilometres inside madurai city 15 kilometres traffic.going behind big trailer lorry for 10 kilometre in 2nd gear route also lot of pot holes frequent gear changes . Coutrallam 5 kilometes inside driving, parking on return journey madurai city traffic very bad 1 st gear driving for 1 kilometre l

Initially vehicle was giving 30 kilometres in four lane roads at 1800 rpm sharp , only 26.8 km mileage in same route but after 11000 kilometres it is giving 30.04 kilometre in same route of potholes , city driving lot of reverse and parking. Without ac with slow progressive acceleration .now the mileage is 34.5 kilometres afer changing diesel filter and third service In the above uploaded photo mileage is 39.2 kmpl [ mileage is 88 % of 39.2 = 34.5 kmpl]. I am using bridgestone tyres 165/80 r14.