I find the mpg display in my 2012 Camry very interesting to observe. Running about town today doing erands it claimed I got 41.6 mpg. Not bad.

I do wonder how accurate it is. Has anybody compared their actual calculated mpg (miles driven divided by gallons used) to what the mpg display in the Camry? If so, what, if any, was the difference?

Thanks.

 

not very...it's about 2 MPG high, maybe more

 

I compare every gas tank fill. It is generally within +/- 5%. On the first several fills it was as likely to read worse as read better. Now of late it seems to read better than the actual calculated mileage more often. And the last tank had the largest error ever. The computer read 23% better than the actual mileage. Not sure what was going on.

Bottom line is that I only trust the calculated mileage based on an average over a few fill ups. That takes out any difference in how full the fill up was.

 

I manually calculate and log every fill-up. Most fill-ups are off between 3% and 4% off with an average of 3.2%. The difference is to the bad, so the MFD is optimistically reading high by 3.2%. YMMV

 

I found the MFD/MID mpg reading is always 2 mpg higher then when calculated. I been filling up at the same level driveway gas pump now for 5 years. This included the '07 TCH I had and now a year of driving the '12 TCH.

It's easier to use and it's much more consistent in it's tank readings. That is if you take the reading when you fill up around 1/4 tank. Somehow it gives slightly higher readings when your above half tank of gas.

By using the mpg readout i'm able to see any mpg improvement or loss per tank by driving the TCH differently.

 

Over 164 tanks in my 07 TCH, the MPG reported by the MFD was 1.1 MPG higher than calculated, on average. This is according to my spreadsheet which does this, and many other fancy calculations for me. Also calculated the the hybrid upgrade (over a standard camry) paid for itself in 33 months and has saved my $1741 since then.

 

I wish all could give a detailed report like you did here. I should change mine to 1.75 mpg difference which was when I owned the '07 TCH for 5 years. At least you know the benefits your '07 TCH had done for you. I rather stick to the mfd reading to compare my driving habits. I had problems with the mpg readings fluctuating when I did the calculated using the same pump over the years.

You must have found a pump with a good driveway in front of it to get this close of difference. I searched 5 different top tier gas stations 6 years ago to find one that gave me the least difference between the calculated and using the mfd readout.

 

Over the last 130,000 miles or so, the MFD is consistently indicating just under 2 mpg higher than my calculated mileage. Even stranger, the differential remained constant after the local stations started selling 10% ethanol and my mileage dropped by +/- 8%.