Welcome to PriusChat

We'd love to have you join our community and participate in the conversation! Sign up for FREE today.

Sign Up

OK wHAT HAPPENS IF YOU PUT IN 4 QUARTS OF OIL?

Discussion in 'Gen II Prius Care, Maintenance and Troubleshooting' started by ski.dive, Apr 14, 2010.

Social Buttons

  1. ski.dive

    ski.dive Member

    Joined:
    Jun 11, 2008
    Messages:
    343
    Likes Received:
    19
    Location:
    Hutchinson Island,FL. Mt. Snow,VT
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A
    2008 PRIUS, I put in 4 quarts of oil instead of 3.9 quarts, what will happen?

    How can 2 ounces make a difference?

    Are overfilling problems by 2 ounces a MyTH and B.S. INFO???
  2. boppo

    boppo Active Member

    Joined:
    Mar 11, 2009
    Messages:
    775
    Likes Received:
    129
    Location:
    Owego, NY
    Your Vehicle Year:
    2006 Prius
    Model:
    II


    little less MPG. 3.75 would be good.
  3. Dark_matter_doesn't

    Dark_matter_doesn't Prius Tinkerer

    Joined:
    Aug 8, 2009
    Messages:
    655
    Likes Received:
    130
    Location:
    Seattle, WA
    Your Vehicle Year:
    2010 Prius
    Model:
    IV


    Engine oil capacity w/filter change on a 2010 Prius is 4.4 qts. With 4 qts, you should see the dipstick level about 2/3 from the bottom.
  4. David Beale

    David Beale Senior Member

    Joined:
    Jul 24, 2006
    Messages:
    4,194
    Likes Received:
    604
    Location:
    Edmonton Alberta
    Your Vehicle Year:
    2012 Prius
    Model:
    N/A
    Yup, posted in the wrong section of the forum. Perhaps a mod. will move this for you.

    Second gen. -may- experience a slight drop in mileage with a bit too much oil, but 4 qts. may be ok for a 3rd gen.
  5. ski.dive

    ski.dive Member

    Joined:
    Jun 11, 2008
    Messages:
    343
    Likes Received:
    19
    Location:
    Hutchinson Island,FL. Mt. Snow,VT
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A
    I've been getting 46.5 mpg over the last 150 miles.

    I'm going to check my mileage with 4 full quarts of oil, to see if it is a MYTH and get less mpg's with an over fill by 2 ounces.
  6. Patrick Wong

    Patrick Wong DIY Enthusiast

    Joined:
    Mar 8, 2008
    Messages:
    13,490
    Likes Received:
    3,241
    Location:
    Green Valley, AZ
    Your Vehicle Year:
    2007 Prius
    Model:
    N/A


    I doubt that you will see any change with such a tiny change in oil level.

    What might be more interesting is if you were to monitor your mpg with 3 quarts of oil in the crankcase, and see if there's any improvement. That will still give you an oil level above the bottom dimple on the dipstick.
  7. paulemus

    paulemus New Member

    Joined:
    Jan 4, 2010
    Messages:
    93
    Likes Received:
    8
    Location:
    San Diego
    Your Vehicle Year:
    2010 Prius
    Model:
    IV
    You might get a big bill down the road for replacing oil seals. Most dipsticks clearly warn: Do not overfill.
  8. ski.dive

    ski.dive Member

    Joined:
    Jun 11, 2008
    Messages:
    343
    Likes Received:
    19
    Location:
    Hutchinson Island,FL. Mt. Snow,VT
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A


    Tell me...How am I going to damage my OIL SEALS, by having 4 quarts of oil instead of 3.9 quarts of oil in my motor?:mad:
    That's only 2-3 extra ounces of oil.:mad:
  9. richard schumacher

    richard schumacher shortbus driver

    Joined:
    Mar 27, 2004
    Messages:
    7,652
    Likes Received:
    877
    Location:
    United States
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A
    3.9 quarts is the dry system capacity. At an oil change 3.5 quarts will fill the system including the filter. Three quarts exactly works just fine. Try it.

    It may not damage any seals but even a little overfilling has been found to start fouling the MAF. That can reduce fuel economy drastically.
  10. CharlesJ

    CharlesJ Member

    Joined:
    Dec 13, 2008
    Messages:
    461
    Likes Received:
    24
    Location:
    Monterey
    Your Vehicle Year:
    2008 Prius


    No matter how many fuel tanks you go through, there is enough variability from tank to tank that such a change will ever show up, if it is in fact a real change. You just cannot get a good feel for MPG even if the level, whatever you have it at will remain the same from tank to tank. Urban legends;)
  11. chuckknight

    chuckknight New Member

    Joined:
    Oct 27, 2009
    Messages:
    194
    Likes Received:
    33
    Location:
    Texas
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A


    In reality, you wouldn't cause any damage. BUT it'd be a good excuse to refuse any warranty claims, if you have a shady dealer where you live.

    After all, even if it was only extremely minimal overfilling, they'd legitimately have a point that it was overfilled.
  12. ski.dive

    ski.dive Member

    Joined:
    Jun 11, 2008
    Messages:
    343
    Likes Received:
    19
    Location:
    Hutchinson Island,FL. Mt. Snow,VT
    Your Vehicle Year:
    2008 Prius
    Model:
    N/A
    What size threads is on the prius oil drain plug
    in order to get a drain valve?
  13. turnbowm

    turnbowm Junior Member

    Joined:
    Jun 17, 2008
    Messages:
    80
    Likes Received:
    5
    Location:
    So. Calif.
    Your Vehicle Year:
    2008 Prius


    FWIW, my 2008 Prius was overfilled (~3/16" above the full mark) by the factory and again by the dealer at 5,000 miles. This seems to be common practice by many Toyota dealerships.

    IMHO, Toyota would be on very shaky ground trying to deny a warranty claim for this reason. They tried this with the engine sludging problem a few years back and lost big time!
  14. hobbit

    hobbit Senior Member

    Joined:
    Mar 23, 2005
    Messages:
    4,084
    Likes Received:
    415
    Location:
    Bahstahn
    Your Vehicle Year:
    2004 Prius
    Model:
    N/A
    3 quarts *is* sufficient for a drain/refill and filter change in
    a second-gen, placing the level somewhere between the marks on
    the stick [duh, like we were taught to check for back in the day]
    but on the lower side of that range. The third-gen takes a little
    more. Most of my changes are less than 3.5 quarts these days, and
    I keep an eye on it for any need of a top-up but it doesn't seem
    to lose any at all between changes. Mostly filling the new filter
    before putting it on helps re-establish circulation a little
    faster at startup.
    .
    _H*
Similar Threads: HAPPENS QUARTS
Forum Title Date
Prius v Technical Discussion What happens : 'surplus energy' on freeway Nov 15, 2014
Gen III 2010+ Prius Care, Maintenance and Troubles What happens when 12v battery dies? Jan 8, 2014
Other Cars Yahoo Autos: Bold School: What Happens During a(n auto) Recall? Jul 28, 2013
Prius c Main Forum What exactly happens at the financing dept? Jun 8, 2013
Gen III 2010+ Prius Main Forum Press Park button when moving - what happens? Apr 14, 2013