Do you fill a full 65L when you drive 650km? If not you are not calculating correctly. I don't think I've fit more than 55L in mine even after the light comes on.

Hyunday owners won an lawsuit over that same reason. We should get together and do as they did.

https://hyundaifuelconsumption.ca/fr/

Bad memories
 

I bought the RVR in January 2011 and battled for months with the dealer and the manufacturer over the very falsely advertised fuel consumption. I have since moved away and haven't driven the car for 2 years but have returned for the holidays and again am furious at how awful the consumption is. Wish I never bought this car.

I am driving my RVR for almost 3 years now. The gas is around 10.5L/100km during summer and 12.5L/100 km during winter. Never did I able to see a 6.6L/100Km nor 8.8L/100km. The dealer said that everything is OK but I said no when I complaint the too much gas consumption. I believe a class lawsuit should be started against Mitsubishi. I have my gas records from the time I purchased my RVR.
BTW, I used only Mobil 1 0W/20 in my first change oil up to now. Probably the regular oil will be better?
Also, the TPMS recommendation from my dealer was a bull**** after I installed new TPMS in my winter tires and found that only the dealer can program these and will do another program for the summer; meaning twice in a year for $60/programming + tax, this should be done as gratitude to the original owners...

Any recommendation for a rear view camera?

in addtition to my record for gas consumption, I fill my gas tank only up to when the pump stops fuelling. Meaning, I don't manually press the trigger to add more fuel. Once it stops, I am done and I close the gas cap with one click as per recommendation.