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New to me 2011 Prius why is it getting 35-37MPG!!!

Discussion in 'Gen 3 Prius Main Forum' started by MilkyWay, Jun 20, 2017.

  1. MilkyWay

    MilkyWay Active Member

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    Short backstory: Bought 2011 Prius with 185K Miles

    Work done: New michelin defenders, brakes/rotors

    1 Full tank of gas: My calculation was 35 and I just noticed they have a trip display that shows mpg which also came in at around 35.5

    More work done today: Tune up, egr pipe cleaned, new pcv valve, air/cabin filters

    I have yet to go through a 2nd tank of gas but on my way home from mechanic trip display climbed to 37 or so....

    Owned less than a week....I just noticed and was doing some research on the various speed settings (power, eco, etc.)....I have been driving it in normal mode and I drive with the AC on and I am a slightly faster-than-normal driver.

    My gen 2s easily get 40-42 without effort and I am completely shocked that the gen 3 is doing worse than the gen 2!

    35 is still good compared to other cars but it is advertised as 50mpg! I was expecting 45mpg...

    Here are some of the old components...EGR was a little dirty but mechanic said it wasn't that bad....Spark plugs were shot so hopefully the new Toyota brand plugs will improve mileage.

    Is there any tricks, "magic potions" I can pour in the gas tank, filters I can change?? I skimmed a headline somewhere about a chip that you can run to get up to 80mpg but didn't read into it yet....Under 40 for a gen 3 is kinda unacceptable but hopefully it will get better....

    20170620_124052.jpg 20170620_124101.jpg 20170620_124120.jpg 20170620_125656.jpg 20170620_125703.jpg 20170620_125709.jpg 20170620_125910.jpg 20170620_133757.jpg 20170620_133812.jpg after.jpg
     
  2. bisco

    bisco cookie crumbler

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    start with the new brakes, make sure they aren't dragging.
    i uppose injectors could be dirty at that mileage. how is the 12v health?
    defenders will cost you a couple mpg's, what tyres pressure?
     
  3. Johnny Cakes

    Johnny Cakes Senior Member

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    That is pretty much what my 2014 (35K miles) gets. I do a significant amount of freeway driving, use cruise control, and am somewhat aggressive on starts. I make no effort to draft behind trucks or stuff like that. I figured this was within the standard deviation, but will be interested to read other replies.
     
  4. bat4255

    bat4255 2017 Prius v #2 and 2008 Gen II #2

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    What lengths are your trips?

    Here is what I found on a '16 v
    Summer
    1-5 miles 25 mpg
    5-10 miles 35 mpg
    10+ miles 40+ mpg

    Winter is about 2-5 mpg less
     
  5. WilDavis

    WilDavis Senior Member

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    ...er, um, how heavy is your right hoof?;)
     
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  6. Mendel Leisk

    Mendel Leisk Senior Member

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    Where did you get the brakes done? It's easy for a mechanic not familiar with 3rd gen rear brakes to get the caliper piston orientation wrong, creating a lot of drag. A couple of tests for this:

    1. Feel the middle of the rear wheels after an extended drive. They should not feel any more than barely warm. If they are hot to the touch the brakes are dragging.

    2. To confirm, jack up the rear of the car (put (wheel chocks on the front wheels), and with the parking braking brake off (obviously) spin the wheels. They will likely drag a bit, but should be fairly easy to spin, go a revolution or two after a good push. The should not be dragging significantly.

    If they are, and doubly so if it was non-Toyota mechanic, the caliper pistons are likely mis-positioned, causing drag and uneven brake pad pressure as well. The rear brakes in 3rd gen and onward are disc brakes with integrated parking brake, and the back of the pads have a pin which MUST be positioned and locked between the spokes on the face of the caliper piston. If this doesn't happen the piston is bearing ON the pin, skewing everything, dragging royally, and messing up the rotors.

    I'll attach Repair Manual pdf on on the brakes. Rear brakes are the second half, and there's some picture and instruction regarding piston orientation. You want to ensure the pin is in between the spokes, and before parking brake is applied the pads are firmly seated. Best to depress the brake multiple times before reconnection the 12 volt, then test drive, and only then apply the parking brake.

    Not sure what a "tune up" is, but judging from the condition of the EGR pipe, and considering 185K on the odo, your EGR cooler, valve, the intake manifold where EGR connects, could all badlly clogged. The EGR pipe is kind of the canary in the coal mine. If it's badly clogged it could be dropping mpg I think.
     

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  7. orenji

    orenji Senior Member

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    I can easily get 50 mpg. It's all about how you drive. It's not a sports car so don't drive that way. Learn to coast a lot when you see a red light. Stay within the Eco range.
     
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  8. MilkyWay

    MilkyWay Active Member

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    Belle Tire and it has a lifetime warranty on the brakes if they ever go bad they replace. They did change 1 rear right caliper bolt.

    By tune-up I meant spark plugs.
     
  9. Mendel Leisk

    Mendel Leisk Senior Member

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    Uh oh. Do the tests: they may have done it right, or not.
     
  10. AzWxGuy

    AzWxGuy Weather Guy

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    The brake work would have elicited the disconnection of the 12V aux battery, and this will reset various records on the vehicle. So you will have to accumulate some miles to get back to reasonable mpg readings. If it is still low after a week or two then I would look into other possibilities.
     
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  11. Mendel Leisk

    Mendel Leisk Senior Member

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    I've got the impression it takes a couple of start-up-and-drive for the car to "clear it's head". After doing brake work with 12 volt disconnect, the car will display a somewhat alarming revving up, especially just after starting, like it's recalibrating throttle response or something. I would say within a day it's back to status quo, just my impression though.

    Also, who knows what Belle Auto did. It's not the usual to need to disconnect 12 volt. Maybe they didn't, and got lucky?

    It's may not strictly be needed, if you're very careful not to open driver's door, and also tromp the brake pedal multiple times before restarting the car, so that an "excess brake pedal travel" is not detected.

    All speculation though. For the DIY'r, it's better safe than sorry, doing the 12 volt disconnect.
     
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  12. NavyLCDR

    NavyLCDR Active Member

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    Run it in ECON mode, not Normal mode. When you are circling a parking lot looking for a parking spot, or on a long, level lower speed limit section of road, hit the EV button. You can't get 50 mpg in a Prius and drive it like a sports car.

    When I first got my 2011 used Prius I ran a set of Lucas Oil Complete Fuel System Renewal through it (4 successive tankfuls) - after oil change and spark plug change.

    Bump the tire pressure up. I like to run 42 front/40 rear. Some owners go to 44 front/42 rear.

    Try Mobil 1 0w-20 Advanced Fuel Economy oil. Frequently check the dipstick for oil consumption and only switch to High Mileage oil if you have to. Most oil additives are higher weight (usually 30W), so I wouldn't use any of them.

    Don't expect overnight jumps to 50 MPG. Use Trip A to record long distance average MPG and I like to reset Trip B every tank of gas.

    My 135,000 mile 2011 Prius Three was running 48.5 mpg long term over the Winter. Last tank of gas is at 50.5 mpg now that the weather has warmed up here in NW Washington State.
     
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  13. maurices

    maurices Member

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    I am wondering if the battery pack is bad. The mileage you are getting sounds like ICE operation only. The mileage is similar to what I get in the winter when the ICE has to run a lot more to achieve operating temperature.
     
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  14. MilkyWay

    MilkyWay Active Member

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    Hybrid battery or 12V? I can't really explain much as I don't understand the mechanics at all but it definitely switches from non-running electric to gas like my gen 2 did at idle....And zero warning lights...And starts every time...

    The dash shows bars in 0-25mpg when I accelerate....When I let go of the pedal the bars go to 100mpg (max)....Haven't done 2nd fill up yet but screen is showing 36.5 right now.

    When I had cruise on today on freeway it seemed to have bars just below 50mpg which was nice to see...won't know true data until I hit the gas station tomorrow...will update.
     
  15. bisco

    bisco cookie crumbler

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    agreed.
     
  16. MilkyWay

    MilkyWay Active Member

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    I am up to 38-39 and I'm sure I could get 41 or 2 if I did more "coasting" (foot off gas pedal and mpg shoots to 100) but drivers behind me would be pissed. Filled up maybe 2 or 3 more times since last post.

    If I knew the mileage sucked so bad I'd have went with the Michelin energy savers.
     
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  17. bisco

    bisco cookie crumbler

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    defenders might be costing you 305 mpg, are you running 42/40?
     
  18. Robert Holt

    Robert Holt Senior Member

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    The causal locus of your poor mpg is ambiguous. Can you find a friendly nearby experienced Prius driver to test drive your car and see what he/she gets, AND watch you drive your car to fine tune the way you operate it? Hopefully that would either isolate the cause in the way the car is operated , or in the physical aspects of the car, and we can go from there. Good luck!
     
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  19. MilkyWay

    MilkyWay Active Member

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    Thanks...Also noticed that when I checked oil today (1300 miles put on her since purchase) she was a little over a 1/2 quart low...Not too terrible, burning approximately a full quart every 2500 miles is my guess.

    But, I am pretty sure oil change shop used 5W20 Mobil One and they said it calls for 0W20....

    I will either do myself or I do have a coupon from registering on Log into Your Toyota Owners Account | Toyota Owners

    where they are doing a $59.99 full synthetic oil change + tire rotation + 12V battery check + multipoint inspection....Might take it to them at around 3,000 miles.

    Guy at shop said oil looked dirty also and I did engine flush on first change....

    Might put her up for $5995 and dump it!!!!!! I got a really good deal and only have a little over 4000 into it (2011 approaching 186,000 miles).
     
    #19 MilkyWay, Jul 1, 2017
    Last edited: Jul 1, 2017
  20. MilkyWay

    MilkyWay Active Member

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    42 tire pressure in front 40 in back? I am not sure, Belle Tire put on the new tires so it is whatever they filled up to...Haven't checked yet.