MPG study

Hi Splendid. Can you post the reported voltages of the new battery after it's been in the car and been driven for a few days (to make sure its charged).

thanks

 

you need to calibrate with other mapping options. map a route out with google maps. try a loop of a mile or so and run it 10 times and see what it says.

having resting voltage of 12 volts give or take is fine overnight.

no doubt about that. should not go below 11 volts. when engine is on, should sit around 14.2 volts. one cell is probably dead

that should clear it up. another thing is you filled up when you got the car. the error of that fillup is a constant. a new battery should help and the tires in most cases will cost you at least 2- 3 mpg.

also, the bladder fills more inconsistently when its cold. wait till summer when its hot, you will see more consistent numbers

 

You state that you just bought the car and so the dealer probably put new tires on to sell it. regardless of brand they will require some run in to get the best mileage. That hith 12 volt charging could be you problem. I believe a higher psi will help. Try inflating to max sidewall figure until tires get worn in. I run 48/50 and though the ride is rougher I find good steering and 48 mpg in below 30 degree temp and short trips the norm.

 

I created a 10 year Excel spreadsheet (attached) to track my actual MPG vs. the Multi function display (MFD) readout for my 2009 (I live in the Pacific Northwest). I've been really dedicated to this effort, and haven't missed any fill up data.

My lifetime MPG and the lifetime MFD display are all weighted (you can check the formula I used for those fields), in order to overcome any tank-by-tank variances we often see due to the variability of the bladder fuel cell.

As you can see, after 10,000 miles, my assessment is the MFD display is indeed "generous," indicating 1.5 MPG (about 3%) greater fuel economy than I actually achieve (orange colored columns). Not too bad for a car computer, but this hints of a Toyota conspiracy to mislead the consumer.

As for gas pump variance, I rarely buy gas from the same pump and often mix up which vendor I use, and I believe the gas pumps are federally calibrated, so I don't attribute the difference to the pumps charging me for more gas than was actually dispensed, but I suppose that's a possibility (and another conspiracy), too.

 

I'm not quite sure how you reached the conclusion that inaccuracy = conspiracy to mislead.

The MFD is based on certain inputs that have regulated tolerances. For obvious reasons, the devices are designed to prefer overindication to underindication (e.g. speedo will show a faster speed than actual).

Gas pumps are not federally calibrated, per se. The requirements are set by the federal government but the inspection is done on the county level, at least that is my experience from the East Coast. It looks like some jurisdictions do it at the state level. Media testing of gas pumps has found a variance, generally but not always favored towards the consumer (the pumps are designed to wear in the customer's favor).

Check out this county, which publicizes all their inspections:

Maricopa County fuel pump inspections