Prius MPG increase after "break-in period"...

I think it is pretty much the way Yogi said:

"Gas Mileage is 90 percent mental and the other half is the way you drive."

ß

 

I did get a decent increase after about 12000 miles. Before that I used to average just under 50 mpg in normal driving ( 51 or so on long drives, as low as 45-47 on errands). After that I have been recieving 52-53 mpg consistently. Thus an increase of around 3 mpg. Great !!!

 

I just don't know yet. I hope there's one. I certainly feel that my driving technique has improved, despite a general (hopefully winter related) decline in mpg from 52+ to 50+ mpg over not quite 2500 miles.

That said, I would not be at all disappointed in staying in the 50-52.5 range... sure beats the 17 I used to get!

 

This is interesting. Has anyone else noticed or reported their car not operating in stealth mode until after 1000 miles? My car only has 80 miles, but I noticed it operating in stealth mode in a parking lot today.

 

That's been my experience.
Of course, if the car has just been started, the engine will be running to warm up and it will be used, even in a parking lot.

 

I think my climate has too many extremes to point to a "magic" odometer reading beyond which the fuel economy goes up. When I first purchased my 2004, I could easily get 4.8 l/100km in city driving, with temps of +22 C.

Last winter was an especially brutal one with long stretches of -40, and my fuel economy plummeted to 9.8 l/100km. It had around 12,000km on it at that time.

Summer of 2005 I regularly got 4.2-4.5 l/100km in city driving, and 4.5 l/100km on a road trip to Rochester, MN, and back. I was running Mobil 1 0W-30 and had the cruise set at the posted speed limit.

So far this winter has been very mild, almost a record setter, so I'm still averaging 5.1-5.4 l/100km. I did notice a difference running Mobil 1 0W-20, but I'm reluctant to recommend using a viscosity not officially supported by Toyota. Hold on a few more weeks and I'll post the UOA, so we can all see if there is anything unusual with the wear metals.

Using my winter front to completely block off the grille also made a difference. Too bad Toyota never thought of offering a coolant temp gauge to make this a bit less nerve racking.

Most of the fuel economy "break in" increase - if there is one - can be driver or human factors. Some of it is true break-in. Proper tire pressure is a must. Cold temps and winter-blend gasoline really kill your fuel economy.

Synthetic oils may provide a slight fuel economy difference, but nothing on the order of 5-10 MPG unless very unusual conditions: eg winter city driving where the motor never warms up, using a very light synthetic to reduce drag.

Comparing a synthetic 5W-30 to a regular 5W-30, the fuel economy increase is on the order of 0% to perhaps 2%.