Has anyone noticed a discrepancy between what the computer says the tank MPG is and what you calculate old school? I have a 2008 Lexus IS 250 that exaggerates MPG by about 1.2 MPG versus calculation, but the Venza seems to underestimate the MPG. My last tank arithmetic came out at 44 MPG, but the computer lowered my lifetime MPG of 40.6, indicating the tank was lower than that.