We own a 2004 Prius and a 2005 Prius (found a dealer that had next to no waiting list for both). The 2004 Prius has around 20K miles and the 2005 has about 3k. The 2004 Prius has been averaging between 47 and 52 MPG on every tankful. Ever since I got the 2005 Prius I noticed that I was getting significantly less miles per gallon than the 2004. Recognizing that my driving style may be different than my wife's, my wife and I swapped cars for a tankful and she averaged approximately 5.2 MPG less than I did. We tried one additional test. We live in North Carolina and decided to drive both of our cars on the interstate down to Columbia a couple of weeks ago (90+ miles). I drove the 2005 and stayed between 4 and 5 'stripes' behind her on the interstate. We averaged about 65-70 mpg (no cruise control). We filled up on the way back and I found that she averaged 5.8 mpg more than I did even though I tried to stay as uniform a distance as I could behind her. I also spoke to her a number of times while driving to see what her instantaneous mpg was (on straightaways). In almost all cases, she was getting anywhere from 4 to 15 mpg more than me (at that instant). One last point. I did notice that when I press on the accelerator, the 2005 engine 'whooshes' much more quickly than when I do the same on the 2004. I don;t know if that makes sense but it seems that the 2005 revs up much faster. Does anyone have a theory as to what may be going on? Also, I think my 2005 has a filler tube bladder problem. When I fill it up, it generally stops 2-3 gallons short of it being full. When I pull the filler nozzle almost completely out of it, I can add several more gallons of gas. Curiously, when I get it nearly that full, I get a lot of air bubbling out along with some fuel. I called the toyota dealer and they said they have no alerts as to a problem with the filler tube bladder. Thank you for any suggestions you may have. Dave
Dave - My preliminary diagnosis is that you just don't have enough miles on the '05 yet to get the full MPG potential. A well-broken in engine with 20k miles is going to get better milesage than a new one with 3k miles. Also, any differences in oil, gasoline, etc?
some have reported that a "broken in" Prius seems to get better gas mileage. the difference in total mileage on the car may be the reason. as for the filler tube. you should not try to overfill your tank. the gas pump you are using has a sensor that triggers the fuel shutoff switch. that is why you cant seem to get the pump to run after the fuel is shut off. it takes about 30-45 sec for the gas to completely drain back down again. next time you have this problem, try this. after the pump shuts off the first time. remove the filler nozzle. let it sit a minute or two then pump again. when it shuts off the second time (assuming you can get a few more gallons in) hold the nozzle tight against the filler tube to catch anything that might bubble out. a small amount of spilt gas reeks havoc on the environment.
Re: Significant reduction in MPG between 2004 and 2005 Prius Hi Danny.... Thanks a lot for responding. I suspect you are right about the difference in MPG between a broken in 20k engine and a 3k engine. On the other issue, doesn't it sound like I have the same bladder tube problem that plagued early 2004 prius'? Thanks for your response.... Have a very Merry Christmas! dave
Re: Significant reduction in MPG between 2004 and 2005 Prius Hi Dave.... Thanks for your reply. Your point is well taken, and I have already tried that approach (as a matter of fact yesterday). I had driven 418 miles and went to the gas station to fill up. When I filled it up, the gas pumped was 6.2 gallons (averaging amost 68 mpg...). I removed the nozzle from the filler tube. I put it back in and started to pump gas again. It stopped almost immediately. I pulled the nozzle out until it was almost all of the way out. When I started to pump the gas, this time I could hear the gas flowing into the tank. I proceeded to pump 3.6 gallons more into it. Unfortunately, as you pointed out, when I pulled the nozzle out, air and gas started bubbling out of the tank. I realize it has a sensor, but it still seems to be a problem that I could put that much more gas into the car. Respectfully, Dave
the bladder tube problem was fixed (so its been rumored) about half way through the 2004 model year. so all the 2005's have the fix (well as fixed as its gonna get) on the nozzle. if you look at it, it has a small hole next to the big hole. that is the backflow sensor. when it senses backflow, it shuts off the switch. it takes as much as a minute to reset itself. without resetting, the pump will not run to fill even an empty tank. i have experienced the same thing and have noticed that some pumps dont seem to reset at all no matter how long you wait. i feel that the reset is tied to the pump switch (the handle you flip when getting ready to fuel) but dont really know. but at the same time, i dont have that much of an urge to stretch my tank. i usually fill up within 20 miles of the blinking bar (if i wait that long. have actually only seen the blinking bar about 3-4 times) UPDATE... looking at my mileage chart, i can say that ive seen the blinking bar probably 4 times since i have 4 fillups between 9.6 and 9.8 gallons. i frequently take trips of over 100 miles roundtrip so i try not to do those with less than 2 bars if possible. i rather get gas at the station i am familiar with if possible.
I agree that it's simply a matter of getting the car broken in. Our 01 is out performing the new 05. However, on Friday we topped the 1000 mark and I noticed a significant difference in the car. Almost like 1000 was a hard set number in code somewhere and things changed when that number was reached. I don't really think this, but wouldn't be surprised if that was the case.
Re: Significant reduction in MPG between 2004 and 2005 Prius I have noticed no change whatsoever in mpgs since my car was new, and it now has almost 15,000 miles.
Re: Significant reduction in MPG between 2004 and 2005 Prius In July, I noticed a big dip in MPG just by getting new tires. That alone made a difference. I also noticed the engine shut off didn't smoothen off until around 7,500 miles. We all know that oil-level & tire-pressure make a big difference too. And with my Classic Prius, I observed MPG improvement due to break-in all the way up to 30,000 miles. Lastly, when was the last time you filled up? Is a possibility that the 2004 is still using summer-formula gas and the 2005 winter-forumla gas? Could one simply have different gas, like one being an ethanol blend and/or a different brand. So you've got several factors at play to look closer at.
Re: Significant reduction in MPG between 2004 and 2005 Prius That could be the result of timing... MPG improvement cancelling out the reducing affect of winter-formula gas and lower temperatures.
Thanks for all of your responses. A couple of comments: 1) My wife and I filled up our tanks before taking the trip down to Columbia, SC... so we were both using the same gas. I had 5 bars on my gas guage and she had 2 bars... 2) I don't think the backflow sensor had anything to do with it. For example, today, my wife and I had to drive down to Bluffton, SC for the day (4 hours). I filled up the tank once we got there. There were 363 miles on the odometer and when I filled it up, it stopped a 5.8 gallons. I waited over a minute and tried to restart the flow without success. I pulled out the nozzle until it was nearly out of the hole and proceeded to add over 3 gallons to the tank. When I withdrew the nozzle, I saw a lot of air escaping from the tank and some gurgling of gas (but none left the tank). I think I still have a problem with the bladder, and will take it back to the toyota dealer at 5k inspection. Incidently, we averaged 41 mpg (actual mileage) on the trip down and back from Bluffton. The winter blend of gas may be partially to blame, but there is something amiss here. (see next point). 3) I believe I have an idea of why we may be getting significantly worse mileage on this car (allowing for the break-in period). My wife drove the car today for part of the trip and remarked that the engine seems to race when she lightly presses the accelerator (my comment the other day was the 'whoosh' sound). Her car's engine (2004) does not 'race' unless she presses harder on the accelerator in her car than she does in mine. In the 2005, the engine winds up quickly just pressing lightly on the accelerator. Thanks for your patience.....Dave
Re: Significant reduction in MPG between 2004 and 2005 Prius :? I have had my 2004 Prius since April. Intially I averaged about 49 miles per gallon. In August I got the 5000 miles service done and it immediately dropped to about 43 mpg. We went on a vacation and I thought it was due to the different conditions but it stayed lower all fall. Well a few weeks ago I got the 10,000 miles servicing done and now I am averaging about 39 mpg. We just checked the tires and found the right front one to be about 4 pounds too high but the rest of the tires were on target with Toyota specs. I have never over inflated the tires in an effort to increase mpg. Do you think the right front tire being over inflated could have impacted my mileage this much? Any other ideas? Tara
Similar experience here. I was averaging 49mpg pre-5k-mile oil change, and 45-46 after. I just had the 10k change, but all bets are off regarding oil as a factor. Today, I noticed that the dealer sticker said they used 10W30 oil, even though the Prius manual specifies 5W. I called the dealer and complained, and the asst svc mgr said "We put 10W30 in all Toyotas, because it's most appropriate to the southern CA climate." Further dealer service beefs: At the 5k service, they OVERFILLED the oil and UNDERFILLED the tires. No idea what weight oil they used, because that line on the sticker was blank. When I made the 10k service appointment, I asked about the 40L brake light switch TSB, and they said they had the parts in stock, and they'd do it too. After I brought the car in, they said they'd have to order the part after all, and that I'd have to bring the car back again. To add insult to injury, a tire exploded on my drive home from work today, 24 hrs after the service. Coincidence, or (dramatically) wrong tire pressure again? Either way, Toyota Customer Service is about to get a scorching letter from me. :cussing: At least a package from Coastal with my XM, EV, and door lock mods will be arriving tomorrow.
Re: Significant reduction in MPG between 2004 and 2005 Prius <div class='quotetop'>QUOTE(tara\";p=\"60394)</div> I wonder if they used the correct weight of oil.
Re: Significant reduction in MPG between 2004 and 2005 Prius I think that all prii should use Mobil-1 Synthetic Oil. Its the best oil out there. I have to use it in my Evo. Plus, its a synthetic oil (for you treehuggers). :mrgreen: <--[Evo]
I have a 2005 w/ almost 260,000 miles. I am just starting to see the bladder issue after owning a month. When I first bought it the tank was full up. It took like two weeks to get to 3 clicks from empty. I have had Jaguar that used premium 91 octane or higher only. It got like 16-18mpg. The tank was about 11 gallons. I figure I am getting 46-48mpg now. I can handle 5-6 gallons. I am still driving like 300 miles between refills, lol. Thats better than 250-300 at Premium prices.
