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MPG Decrease After Servicing

Discussion in 'Gen 2 Prius Fuel Economy' started by tguyton93551, Jul 17, 2005.

  1. tguyton93551

    tguyton93551 New Member

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    I have over 60,000 miles on my 2003 Prius. MPG has been a steady 43 since I bought the car. I recently took it in to the dealer for routine maintenance, which included cleaning the fuel injectors at their reccommendation. I saw an immediate decrease in MPG, but didn't think too much about it, thinking it was just an anomoly. A week or two after the servicing I bought new tires and went to 185s vs. 175s hoping for better tire wear. After I had driven the car for about a month with MPG running a steady 37 vs. the previous 43, I took it back to the dealer. They checked it, said there was nothing wrong with the car, and said it must be the tires. I'm running 42/40 pressure in the tires and can't believe the 10mm of width would make any difference in MPG, much less 14%.

    Anybody else have a similar experience?
     
  2. vprius

    vprius New Member

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    Did you check that they didn't overfill the oil? That has been a problem with some services, and resulted in lower mpg.

    Otherwise it could be this hot weather. I imagine Palmdale must be blazing...I know Bakersfield is. Mileage has dropped to 40mpg for me with these 106-108 temps. Air has to keep running all the time...even with temp set at 77.
     
  3. kirbinster

    kirbinster Member

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    Just goes to support the old adage, if it ain't broke don't fix it! Sorry, just could not resist. :)
     
  4. tguyton93551

    tguyton93551 New Member

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    Viprius: Oil is not overfilled. Yes, hotter than hell right now, but the problem pre-dates the hot weather. Also, I have had the car for 2 years and have not noticed any appreciable difference in hot(ter) weather.

    kirbinster: Cleaning injectors at 60,000 miles doesn't seem unreasonable to me. And I know from experience that dirty injectors can cause problems at the most inopportune time. Is your point really "don't trust dealers"?
     
  5. kirbinster

    kirbinster Member

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    I generally find dealers do a poor job, but I guess with the Prius there are not too many other places that know how to service them. I have a great independent mechanic for my BMW and never go to the dealer.

    What is it that they actually do to clean a fuel injector - do they take it apart? Can't you do the same think by using something like Techron (an additive by Chevron). That is what they always used on a Volvo I had years ago.

    I guess my feeling is that if you are not having problems with an injector and are getting good mileage and good performance why ask for trouble. Why not wait for performance to degrade and then work on it. I would not do that with something like a timing belt, that can fail catastrophically and damage the engine, but if an injector starts acting up isn't the worse that will happen is you will get poor mileage or poor performance?
     
  6. popoff

    popoff New Member

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    <div class='quotetop'>QUOTE(kirbinster\";p=\"108048)</div>
    I routinely add Techron every 3rd or 4th tankful because I've heard repeatedly it's the best product of its' type. There are two bottles sold that have "Techron" written on them. I've forgotten the exact distinction but I believe one is a gas additive "with Techron" and the other displays Techron more prominently on the bottle.

    Fuel injector cleaning is a great profit maker for dealers and auto shops. I would never have my injectors cleaned unless there were symptoms that showed it was required.

    In addition to using the additive, I fill up with Chevron when possible since it already has Techron in it.

    FWIW>
     
  7. tguyton93551

    tguyton93551 New Member

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    I don't know that the injector cleaning had anything to do with the problem. I just mentioned it because it was the only thing done other than routine servicing.
     
  8. kirbinster

    kirbinster Member

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    I would venture to say they did something wrong and it is dumping too much fuel and you are running rich. This will waste gas not to mention it could kill your catalytic converter. Take it back and make them un-screw up!
     
  9. tguyton93551

    tguyton93551 New Member

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    Did take it back. They say there is nothing wrong. Blamed the increase in tire width, as I said in my first posting.
     
  10. Frank Hudon

    Frank Hudon Senior Member

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    if you had LRR's on the car and changed to non-LRR's that the reason for you mileage drop. The Classic was designed to use them and most other's kill your mileage. Not sure what brand you had on it but if it was Bridgestone Potenza or Dunlop SP10's and changed to some other I'd say that's your problem.
     
  11. Tideland Prius

    Tideland Prius Moderator of the North
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    Funny, I noticed our Camry's average fuel economy reading dropped after the fuel injector cleaning. Now I'm a big NON-believer of these things and always assumed that it's for dealers to make money, especially since they added it without telling us before hand. Nowhere in the service manual does it say to add fuel injector cleaner. But if it's not the cleaner, then why the sudden rise in fuel economy?