Hello to the group
 

Hi,

Recently purchased a brand new 2015 Toyota Prius. After 1.5 months from purchase drove to Yellowstone national park, WY from Minnetonka, MN. Approximately 2700 miles put in that trip. Average mileage reported by gauge is 50.1 mpg. Very impressed.

When I reached yellowstone national park, average mileage of the trip was 42 mpg. I drove through steep mountains (Mount Rushmore, Bighorn National Forest) and also drove in I90 (Minnesota, South Dakota, Wyoming) at 70-80 mph with A/C on most of the time (warm days).

Mileage when driving inside yellowstone national park and returning to nearest town was very impressive. Best i got was 82 mpg when driving from east entrance of the park to Cody, WY for 49 miles. Another day i got 75 mpg for the same trip.

When returning from Cody, WY to Minnetonka, MN i got 50+ mpg consistently. Drove in I90 at 72 mph A/C on and off sometimes (cold days).

I am unable to tell why there was inconsistent mileage between forward and return journeys.

I am not sure if it was due to engine break in period because i got 50+ mpg consistently in local driving in Minneapolis area prior to my road trip.

Is it due to all uphill driving when going to Wyoming and downhill driving while returning? Does anyone know?

Hello and welcome. I wouldn't worry about your inconsistent figures, hybrids are a mixed bag, where conventional cars struggle in urban environments, hybrids can excel, and on highways where a normal car will get good economy, hybrids can sometimes suffer.

Many things can affect your fuel consumption, a car will use no fuel going downhill, so long as you're not accelerating. Uphill can drink a lot of fuel in any car. I would just look at your average economy overall, that's what matters, and remember your car is pretty new so will take a while to break in.

Also I'd like to ask, I'm not sure of your fuel tank size, but you appear to be filling up very early. I'm assuming you have a tank range of 800 to 900 miles, and yet I see fuel ups after less than 200 miles, which is probably a quarter of a tank? Why so soon?

Thanks for your comments.

Fuel tank has 11 gallons capacity. Range is 550 to 650 miles. Recent fuel ups from Aug 15th was part of my trip to Yellowstone trip. I drove 300-400 miles per day since i was travelling my child. I filled up tank at the end of day so that next day when driving i don't need to take an exit for fueling. Otherwise, i used to fill once in 2-3 weeks depending upon how much i drive.

Ok seems an unusual way of doing things, I have a car with a good range too, but I feel like it's best to run it down to take advantage of the long range!

I see the Prius has a 45 litre tank, same size as mine, if you fill right up, you'll probably get a bit more in, ive squeezed in 14.28 US gallons in so there should be more in there than you think, and you'll have a longer range too.