Got through the first tank of fuel (499.5 miles on Shell 87) and calculated a 56.3mpg average. Display indicated 53.9mpg... which one should I consider more accurate? I also discovered that I had nearly 3 gallons of fuel left at fillup (pumped 8.9 gallons) so I can drive back and forth to work a couple more times with the light blinking. My thought is different pumps will click off at different times before it's 'full' so do I consider the indicated average my mpg? Thanks.

 

You did fabulous, especially for a first tank! Tank to tank either method works but overtime I have used gallons purchased to manually calculate mpg. This is the actual mpg you are/will get and over time is the most accurate. I have found that the display mpg is generally 3% to 4% optimistic versus actual calculations, but this can vary by 5% up or down, or more, with individual tanks. I try to use the same pump at the same station because you are right, there will be some variance from pump to pump and station to station.

 

Congratulations on an excellent start and your stats should only get better as the car gets "broken in" and with warmer summer months ahead.

Generally the display shows higher mpg than the calculated for a tank.

After 41 tanks, my calculated showed higher 12 times; the display showed higher 29 times and overall display is 1.4 mpg higher than calculated.

For those not concerned with keeping data, then 'both are quite similar'

 

499.5 miles / 8.9 gallons is 56.12MPG not 56.3MPG, but that's pennies anyway.

"Fuel economy EPA highway (mpg): 51 and EPA city (mpg): 60"

I think you're right on the money with a 56MPG tank.

 

It was 499.5 miles on 8.88 gallons... I rounded the gallons, sorry I feel I could have gotten better because ~160 miles of the tank was a freeway roadtrip at 70mph averaging low 50's-mpg. I am hoping for close to 60mpg next tank! I love it, this car is saving me ~$100/mo. in fuel!!

 

Noooooooo!! Don't do it!

The Prius is notorious for failing to fill all the way to its rated capacity. People who try to estimate their cruising range based on 11.9 gallons usually end up by the side of the road waiting for AAA. You MUST fill when it tells you to fill. And no, the hybrid battery should not be relied upon to get you even a short distance to a gas station.

Good mileage, though. Thumbs up for that.

 

Copy that... add fuel means add fuel.

So far this next tank I am at a 61.6mpg average!!

 

Did anyone mentioned the bladder thing? please do a little research on the bladder issue, that will further convince you to go for gas when it tells you to do it.