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Mileage change

Discussion in 'Gen 2 Prius Fuel Economy' started by yensid, Oct 29, 2005.

  1. yensid

    yensid New Member

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    I took my prius in for an oil change, fuel injection service and a change in power inverter coolant. Well my Prius had been getting 49 to 50 MPG between highway and city. After that my mileage dropped to 36 -37. To make matters worse the service department cannot find anything wrong...

    Any ideas?????
     
  2. Bill Merchant

    Bill Merchant absit invidia

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    My idea is that you've given us almost NO information to go on.

    What model/year? Milage? Location/climate? Why did you want to get the injectors cleaned?
     
  3. Wayne

    Wayne Active Member

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    Also, have you checked the oil level and tire pressure since it returned? How many miles have you put on it since you started getting 36-37 MPG?
     
  4. efusco

    efusco Moderator Emeritus
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    I agree, I want to know the answers to all those question too. You must be a rare bird if this is an '04+ over 100k miles for the inverter coolant change. Also, the most likely answers are 1)lower tire pressure, 2)lower ambient temperture, and 3)winter fuel.
     
  5. yensid

    yensid New Member

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    Bill,

    Sorry about little or NO information. The car is a 2002 that I purchased about 6 weeks ago. I mostly use it on the highway and get about 49-50 on average wtih cruise at 75-80. The tire pressure is 44psi. I live in GA. The maintenance that was done was recommended by the local Toyota dealership.

    Rick
     
  6. yensid

    yensid New Member

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    Wayne,

    I have checked the tire pressure and it was 42 when it went it and they did not bother that. I increased it to 44 psi cold. I have put 3 tanks on it since the oil change. My last tank yielded just 369 miles with just over 10 gallons used.

    Rick
     
  7. yensid

    yensid New Member

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    I don't have 100k miles on this car. Tire pressure has not changed, Temp has dropped a little, I have no idea about the fuel or what I could do about it.

    Rick
     
  8. Wayne

    Wayne Active Member

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    Have you recently started driving lots of those 80MPH highway miles? I've always thought a 2002 got a little less fuel efficiency than my 2005 does, and my 2005 gets less than 40 MPG at 80 MPH. If I turned A/C on, I might be right at your new numbers. It is not fuel efficient on ANY car to drive that fast.

    Here's a test of mine where you may want to look at the MPG-vs-MPH chart I attached:

    http://priuschat.com/index.php?showtopic=1...12&#entry144512

    Also, you did not reply (unless I missed it) if your oil was overfilled or not...
     
  9. Maytrix

    Maytrix Member

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    How many miles had you drive prior to the maintenace? I'm wondering if maybe the before is not as good a comparison as the after. And how many fill ups since? You are aware of the bladder issue and the variance you may see from fill up to fill up? For example - I've had a fill up that gave me a calculated 80mpg. I know that wasn't right. I've also had one of 34mpg. Overall, with the 4500 miles I've driven, my average of all those fill ups is 50.

    And with cruise control set at 75-80, I wouldn't expect 49-50. I'd expect lower.
     
  10. Bill Merchant

    Bill Merchant absit invidia

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    If you don't have 100K miles, this must have been the 60K service. Evan was asking about coolant because the '04+ models have a longer lived fluid. Wayne's right, speed kills (MPGs). The only unanswered variable is the oil level. If they put in too much, that can cut MPGs too.
     
  11. yensid

    yensid New Member

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    The mileage numbers are pretty much with the same settings. Cruise at 75-80, AC on, tires at 44psi, etc. I have been putting around 700 milles a week for 4 weeks and getting the same 48-49 mpg.

    I'll check the oil level.

    Rick
     
  12. yensid

    yensid New Member

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    I have been monitoring my mileage and the meter showing how the hybrid system is operating. what I have found is that on the road my mileage is getting back to the original 49, now at 45-46 on the road even at 80 on cruise control. It is my in town mileage that is causing me the problems. It is not going above the 35-38 mpg range and average in town somewhere from 25-29 mpg. The system seems to be prefering to charge the battery as to using the battery for propulsion. As a result my battery is staying charged fully and in the last 3 weeks I have not seen the battery less than 100% charged.

    To make this problem even more interesting. I was on my way to dinner tonight in the prius. When I went to start the car it gave me several warnings to include check engine light. Maybe now the service tech can find out what is happening to my car. I am puzzled a bit, when I contacted the dealership they told me that I should drive it 8 miles or so to the dealership for service. I have to admit I am a bit concerned about driving the car with the check engine light on.

    Rick
     
  13. hdrygas

    hdrygas New Member

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    Keep us posted and get the actual diagnostic trouble codes DTE. You may get some additional help here, in addition we want to know.
     
  14. Maximous

    Maximous New Member

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    I have on 05 and I noticed a 5mpg decrease since my 1st service at 5,000 mi. I have been trying to figure out what an oil change and tire rotation could do to to cause this. I am now 4,000 miles into the second oil change and still 5mpg lower than I was on the first 5,000. The shop claims to have used 5W-30 oil and put in 3.6Qt, The dipstick is correctly reading full. They did lower my tire pressure, but I pumped it right back up to the 40,37 I have been using. If they used different grade oil than they told me, would it affect this? I am going to provide my own oil and filter next time to be sure.
    I have also recently been experienceing a fuel tank problem. My tank seems to hold less gas now. Could overfilling the tank cause that? I used to get 500 miles/tank no problem and the car would take about 10.5 gal on the blinking bar, now its lucky if I can get 9 gal in it and the bar starts blinking before 400. I noticed this problem after my tank got overfilled once. It took 12gal then I shut off the pump, it did not stop itself. When I removed the nozzle, gas poured out everywhere. the next tanks after that seem to all be smaller.
     
  15. Tideland Prius

    Tideland Prius Moderator of the North
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    It could be that but I'll blame the colder weather.
     
  16. yensid

    yensid New Member

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    Well, I got my car back today. They replaced the ECU and told me that it was fine. On my drive home (in town) I travelled around 35 to 45 mph and got a wopping 34 mpg. So I don't think they still are not finished with my car. I still see the hybrid system disengaging or just not engaging at all. I used to be able to pull off from stops on electric only, now it just gets to about 8 or 9 mph and then its all gas engine. Not sure what's wrong but if they cant fix this I think I want them to buy my car or give me one heck of a trade in on a new one if they can find one.

    Rick
     
  17. Maytrix

    Maytrix Member

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    It could simply be that you need to adjust your in town driving a bit more. Most of the time I accelerate, I don't get any better than 8-9mph before the ICE kicks in. Starting from a dead stop and hills are the biggest killers. Make sure you are anticipating ahead as much as you can. If you can slow down to 10-15mph instead of to 0, you'll save yourself a bit.

    The only time I really find myself in EV is when I accelerate (up to 5-10mph depending on slope), while at a stop, while driving along on flat terrain under 40mph and while gliding downhill.
     
  18. efusco

    efusco Moderator Emeritus
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    While it should be possible to pull away from stops with electric only it takes a very delicate foot and good conditions. In colder weather it's nearly impossible, esp. if the AC is on for heating. Also, you shouldn't try to pull away in electric mode, that is less fuel efficient.

    You didn't mention how far your in-town drive was. If the ICE was cold and the trip fairly short and the weather cool then 34mpg isn't that suprising.

    Drive the entire tank, take some longer drives at steady speed (country roads where you don't have to stop. Variable cycling of the hybrid system is normal..but I have no idea what you mean by "I still see the hybrid system disengaging or just not engaging at all". If your car is able to drive at all then the hybrid system is 'engaged' and working. If the hybrid system isn't working the car doesn't work...the car IS the hybrid system.

    Be patient, although not outside the realm of possibility that something could still be screwed up you definately aren't able to make that determination at this point. Give it a tank or two or three. Keep careful records of temps, conditions, etc.

    Check your oil level. My dealer once gave me a "free" oil change for my trouble when they screwed up my SKS and took weeks to fix it. That was great except I'd just had the oil changed to Mobile 1 synthetic 1 week earlier...they dumped that and put in their basic grade of mineral oil. :angry: Anyway, they could have overfilled your oil if they did that and didn't tell you. Also, check those tire pressures. With colder weather the pressure is probably down a bit and, if you had the car serviced, they probably "helpfully" adjusted the pressure for you and it may not be where you want it.
     
  19. momstoys

    momstoys New Member

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    I expected a drop in mpg from the discussions but it does bother me a bit that my Tacoma hasn't dropped any more than 3 mpg with "winter" gas. My Prius went from averaging 56mpg down to 40-42. And no I don't turn the heat on full at the start despite complaints from the passenger plus keeping it as cool as possible and not freezing.
     
  20. galaxee

    galaxee mostly benevolent

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    remember that your tacoma just has an engine, but your prius has an engine and a battery. batteries are happiest at room temperature, hence the larger effect on your prius.