I must admit, I've never reset the MFD; thought lifetime mpg would be greater than tank mpg. However, I've sat at 43.2 for a week with no budging. If I reset the MFD, will I see an improvement in my actual mpg. BTW, I do keep my gas receipts and write the mpg, the tank mileage, and the overall mileage on my car. I just haven't gotten around to putting this into Cleanmpg.com yet. I have just over 2300 on my Prius right now and will be getting gas next week. What should I do?
How could lifetime mpg be greater than per tank mpg, unless your mileage is steadily dropping? That makes no sense mathematically. Obviously some tank averages will be better than your lifetime average, and some will be worse. As the total miles accumulate, you will see less and less change in your lifetime average for each tank. This is also simple mathematics: each tank makes a smaller percentage contribution to the total. Tom
Sorry, never good at math. That's why my husband helps my 11-year-old with math homework. I need a computer or Excel with the right formula. I guess the answer is to reset the MFD next week.
I reset the mfd at each fillup and use a spreadsheet that calculates a weighted average of all my tanks.
Sandi, the reason the mpg is stuck is 2300 miles of data that created the 43.2. I am at 40000 and reset with every fill-up. In the first 100 miles I can cause the mpg to increase with a little hypermiling, but it has almost no affect when I reach 200 to 300 miles. Most would say to use it to judge how well you are doing on each tank and it also helps point out little problems that arise and affect your miles per gallon. Enjoy, Jerry
Thanks everyone! I will reset it at next fillup. I'm also going to get my tires filled with nitrogen at F44/R42 to see if that helps. I don't change driving week to week. I do pulse and glide (as best as I understand it). I even tried drafting (though I think I did it wrong). I have found I no longer need my speed detector anymore since I'm constantly aware of my speed so I can improve fuel efficiency. I get on my husband when he drives if I see he driving/accelerating too fast, etc. when he drives my car. I will use synthetic when I get the oil changed as well. Again, thanks everyone!
Nitrogen won't help. Do it if you want, but don't pay anything extra for it. Higher pressure will help, whether Nitrogen or air. Tom
>I even tried drafting dangerous. thats a good way to permanently remove yourself from the gene pool.
My 04 resets itself each fill so I can try for a new high score each tank. (well low score here in Australia -.-L/100km)
Thanks for all the responses. I must say, I don't think I was "drafting" correctly because I stayed at least 2, if not 3, car lengths behind. I plan to take all the sage advise (including the nitrogen in the tires) to heart and implement immediately. Don't plan on "drafting" again since I didn't see a result with the way I did it. I don't want to roll under a semi under any means. I have read a lot about nitrogen and I honestly thought (think) it is better. However, I may reconsider based on the comments thus far. Thanks again! I am trying to be fuel efficient as well as green. Every little bit of sage of advise is helpful!!!
I haven't reset my MFD yet (8 weeks). At first it changed pretty quickly (from 45 when I got the car to about 47) and then slowed down. I was at 47.9 for almost a week going nuts trying to get to 48. A couple weeks later and I'm at 48.2, although I was at 48.3 for a day or so, but made a couple short trips today that bumped me back down 0.1 mpg. I guess I'd rather see lifetime mpg rather than per tank, although it would be cool if the car would show both. BTW I haven't done anything to my Prius since I got it. I keep meaning to check the tire pressure but haven't managed to do it yet.
From what I understand the biggest reason Nitrogen helps is that the tire pressure will be more consistent with temperature differences. I think normal everyday fresh air already has something like 78 % nitrogen.
