My Swift VDi’s mileage has dropped about 1kpl ever since my third (10,000 km) service. Can you help figure out possible reasons? I am going in for the 15,000km service soon, so I want to be cautious.
Umesh, via email
AAA It is indeed strange as fuel efficiency is expected to improve slightly post the mileage mark you have mentioned. Check with the service centre if they did something that wasn’t routine – like an ECU flash. Sometimes manufacturers come up with improved versions of engine maps which dealers are instructed to reprogram onto every car that comes in for service.If not, you may have to look into your mileage calculation methods. Check the quantity/quality of fuel you used during the latest test. Fuel efficiency comparisons are pointless if you don’t use the same fuel station and follow the same procedures to fill up and use the same driving styles. It is sometimes impossible to replicate those conditions with 100 percent accuracy over the distance of a full tank of fuel.