I went on my first long drive in my 3 weeke old 2010 Prius and i got 51.4 mpg. And i was on cruise control for most of the time. During the drive i noticed the fuel economy going up and down especially when the car had to accelarate. Is it a good practice to go on Cruise during long distance for better fuel economy? I am just trying to get the hang of driving the Prius and any suggestions are appreciated.
Until you get completely used to the vehicle, the Cruise Control is a decent way to at least maintain your speed, and that in turn increases your economy. However, as many experienced drives here will tell you, you will likely end up doing much better on the mileage if you do it yourself, as you can better determine what the car will need in 500 feet to 1000 feet. (meaning while the CC will push hard as you crest small hills to maintain your speed, thus burning more fuel, if you were doing it, you may slow down a few miles per hour, as you see a long downhill ahead of that.) The best advice to give to maintain great economy: 1.) Keep the car in the 'ECO' mode, as other settings (climate, etc.) are more fuel friendly in this mode) 2.) Stay out of the PWR range of the bar (the red section) as much as possible, as it kills your MPGs... 3.) When giving gas, try to keep your throttle demand in the 25-75 % range, as much as possible when accelerating smoothly. If you do these three things alone, and consistently, there is no reason that you cannot maintain 55-60 mpg in most driving circumstances.
Specifically you can anticipate your speed over hills (speed up before the bottom, slow as you ascend, speed up (when safe) on the way down) better than CC which reacts after the fact. If you never encounter a hill, CC does fine. I can go from Eden MS to Walls MS (155 miles) and gain 80 feet, so CC is less an issue for me.
Huh ... I used to hate them, and now I is one ... I used to wish the truckers would maintain a more constant speed and not slow up and then speed up on the hills' upside & downside ... their quest for mpg has become mine (to a greater extent than before).
I'm assuming you know this, but perhaps not... They don't do this to save fuel - they do it because they can't haul that much weight up the side of a mountain in top gear.
On our first long trip I tried all sorts of tests with each tank of fuel. Eco mode on or off, aircon off and sunroof open, set to 5kph below limit. At the end of the trip I found I could make only about .3 l per 100km difference. Big deal I have decided and now just relax and enjoy the drive. David
I use CC only on long trips to be more comfortable. Otherwise I do it all by myself. On long trips I don't think that CC will do much of a difference in terms of fuel consumption. The major difference in FE is how fast you drive. Moreover, yes, CC will accelerate more "aggressively" as you would probably would, but the excess acceleration is not completely wasted - the battery gets charged more than it would if you were driving keeping constant gas, e.g., so the FE will not be as bad as on another conventional car. The best FE is likely without CC, depending on the road/route. On flat roads, I don't think it makes any notable difference.
