My 2010 Honda Jazz 1.4 EX gives strange fuel consumption results. I filled it to the brim, looked at the computer and it said it could do 490 miles until next fill. I drove approximately 300 miles, at an average, according to the computer, of 53mpg, but the fuel light came on, the gauge dropped to zero, and the computer said that it could only go another nine miles. Something similar has happened several times now. When I fill up from this empty situation, it only seems to take about seven gallons. Either the gauge is wrong or the tank doesn’t hold the 42 litres that I understood it does. I am worried because when I remove the fuel cap, there seems to be some pressure release, I wondered if the tank may have been vacuumed smaller. I know someone whose Peugeot’s plastic tank imploded due to a blocked vent and the fuel pump continuing to suck. The car is still under warranty until the end of August. What do you think?