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Toyota Sienna Gas Mileage



  • kermiekermie Posts: 4
    We have an 04 Seinna and the milage on the overhead display is 2-3 mpg higher that what we get. I wonder if they can be reprogrammed?

  • dnbqeednbqee Posts: 7
    Thanks, yea I wonder. Interesting thing is the miles to empty (usually round 300 for a full tank) is always dead on; ie. the trip computer "knows" the actual fuel mileage but displays 2 mpg more. is this deliberate ? so consumers dont have to see the awful truth of 16 mpg? ours is a awd 04 Sienna is this just a AWD problem ?
  • ateixeiraateixeira Posts: 72,587
    My trip computer is accurate (2007 LE FWD). I've measured on my own (miles for the tank/gallons to full) and it's only been off by 0.1 or 0.2 mpg, and not always reading high, either.

    Just FYI.

    Loaned the van to my lead-footed brother and he "discovered" the 266hp V6. :D 23.3 mpg.
  • We just bought the car this last saturday. We are getting, based on the mileage display in the car, 22mpg in 50/50 mixed driving. How close is the display to actual mileage anyways? I should probably try the search feature... :)
  • ateixeiraateixeira Posts: 72,587
    Mine is pretty accurate, usually within 1/10th of an MPG.

    Just got 24.9 mpg in mine doing about 50/50 city highway.

    So far this tank it says 25.6mpg from mostly highway, but I was stuck on the Chesapeake Bay Bridge last night in that traffic since that tractor trailer drove in to the water (wild).
  • yatesjoyatesjo Posts: 186
    My family and I just returned to San Jose, CA from visiting family in Arizona in our new 2008 Sienna LE. I took along our new Garmin Streetpilot C580 to help us along our way.

    One finding was that the odometer read 4.5% less than the GPS. This was confirmed in two ways. First it was noticed that in the "next turn" estimates that the turn would come up sooner that I expected looking at the odometer so I started marking the odometer readings with the next turn at 100 or 150 miles. This method indicated that the odometer read 95.6% of the GPS distance Later I discovered the trip meter function on the GPS and reset it and one trip odometer for the leg home. Over a GPS indicated distance of 1075.4 miles, the odometer read 1025.1, or 95.4% of the GPS.

    Because of this disparity I have three estimates of the MPG.
    Odometer: 24.7
    GPS: 25.9
    Trip computer: 25.3

    This is 2056 miles of driving on a van that only had 330 miles at the start of the trip. It is about 90% highway and 2 or 3% unpaved roads. Most of the time we were running 75 MPH through 100+oF desert (as high as 112o at one point) with the A/C running full blast. For a vehicle with this much weight and power I am impressed by even the lowest MPG estimate. The A/C can make the whole van cold in those conditions while the engine barely notices and still has a lot of passing power even while going up a 5.5% grade.

    And before anyone asks what I was doing in Arizona in August... my dad has an in-hold in the middle of the national forest in the Dragoon mountains (1.5 hrs southeast of Tucson) and it is not nearly as hot as Phoenix or Tucson. July and August are the monsoon season there and just as the day is getting to it's hottest point the rains roll through and cool the place down. We had thunderstorms most days we were there. Very nice.
  • ateixeiraateixeira Posts: 72,587
    Very interesting, because I would consider the GPS distance to be the most accurate.

    We have a c340, which is less accurate than yours, yet it can tell when I'm in local lanes on the highway. That means it can sense a distance of just a few yards.

    Perhaps the odometer is conservative since some people will mount bigger tires?

    The tires are new so it could not be tire wear.
  • yatesjoyatesjo Posts: 186
    I'm seeing the mileage on the odometer showing less than the actual so my odometer will become closer to accurate as the tires wear down/become smaller in circumference. One thing I must keep in mind too is that my actual speed is actually a little bit higher than the speedometer reading- when my needle pointed to 75mph, the GPS put my speed at 76 or 77mph and the speed signs that flash the actual speed tended to agree with the GPS.

    I agree that the GPS is probably the most reliable measure. The GPS closely agreed with the highway signage distances and is supposed to be accurate to within a few yards. It may miss lane changes or not recognize the differences between the inside and the outside of a curve, but overall those are quite small compared to the length of straight roads I traveled.
  • ateixeiraateixeira Posts: 72,587
    Here's the funny thing - mine is just the opposite.

    When I set cruise control at 65mph on the speedo, my GPS' dash board function usually reads 64mph.

    My Nuvi 200W is not as accurate as your c series, which has a better antennae.
  • yatesjoyatesjo Posts: 186
    Do you have the 16" rims or the 17"? I have the 17" rims and was wondering if small differences in the tire sizing may contribute.

    I chose the C series because of the strong reception. I love this GPS. It made traveling so much less stressful around the big cities and helped me plan where to stop by looking at where rest areas, gas stations and motels ahead of us along our route. Ours also has the MSN service that tells us the traffic, weather and gas prices around the big cities. Going through Phoenix they were working on 101 and the Garmin knew the detour route even before we got there.

    One glitch in the Garmin was that in a remote area it was wanting to send us down unpaved roads- including one that is not maintained and I knew to be impassable without a serious 4-wheel drive truck. I took the route I knew and it kept telling me to turn off on every gravel road I came to. Strangely enough when I turned off the unpaved road avoidance it plotted the most correct (and paved) route. I would guess that the map people coded the paved and unpaved roads backwards in the areas around Dragoon/Cochise/Pearce, AZ.
  • raj1raj1 Posts: 27
    My trip computer displayed around 2 mpg less than manual calcualtion in my new xle!! btw, what does instantaneous?? mpg mean?
  • ateixeiraateixeira Posts: 72,587
    Yeah, I do have the 16" rims.

    Instant MPG is an estimate from the computer on the mileage you are getting on-the-fly.

    I'm sure that's not that accurate, for instance you let off the throttle and it immediately goes to 99mpg, where it seems to top out.
  • yatesjoyatesjo Posts: 186
    The instantaneous MPG is the speed of the vehicle divided by the rate at which gas is being fed to the engine at that second. It goes down when you press the gas and up when you let off the gas and coast. It is basically a tool for watching what habits consume a lot of fuel and what doesn't. I used it with cruise control to know how hard the engine is working at that moment so I would know if I was on a flat or a gentle up slope or gentle down slope.
  • ateixeiraateixeira Posts: 72,587
    It's the car's own bio-feedback. ;)
  • My first six tanks:

    1st tank - 375 miles, 22.7 MPG, 50% highway 50% city

    2nd tank - 261 miles, 19.8 MPG, 30% highway 70% city

    3rd tank - 357 miles, 19.8 MPG, 30% highway 70% city

    4th tank - 472 miles, 32.1 MPG, All highway - 60-65 MPH average

    5th tank - 501 miles, 27.9 MPG, All highway mountain driving - 55 MPH average

    6th tank - 535 miles, 28.5 MPG, All highway - 70 MPH average

    Total of six tanks - 2501 miles, 25.2 MPG

    I am very pleased with these numbers. One of the main reasons I chose the Sienna was current Sienna owner reports of 30+MPG on the highway. The 32 MPG tank above was achieved with a fully loaded van (three people and 400 lbs of cargo).
  • I am new to this forum so please excuse me if there is a prior message on such horrible gas mileage. If you could point me towards the right post that may address this, that would be great.

    We just purchased our Sienna a couple of weeks ago (it is a limited AWD), and were expecting a little hit from the AWD but not this. The on-board computer said like 12.5 mpg when we got the van at 120 miles (I thought it might just be the lead foot test drives), but it is at 700 miles now and reports 11.5 mpg average for that 700 miles, and we drive normally (3 kids in the back :). I topped off for the last two fills and we got 11 mpg this last tank (65% city, 35% highway). I'll be taking her in for service, but any ideas? Acceleration and power seems very good, but we are very concerned when we fill up and the DTE says 215, and we now know that it is accurate. I thought there must be some "mistake" for the first full tank. If our odometer is a little off, that might explain things a bit, but not this much.

  • dnbqeednbqee Posts: 7
    Welcome to the forum. I am fairly new to the forum as well but I came here for the same reason:lousy mileage on our 2004 AWD XLE Limited. I bought the car used with 75000 miles on it and have never cracked the 18 MPG mark, even with all highway driving. Overall average is 15.2 mpg 50/50 city-highway. Overall, the AWD models consistently seem to get mileage that is 25-35% less than the FWD models, no matter what. That being said (disappointing, I know) your situation is truly off the charts. I see 300 DTE after fillup which is accurate, and I'm disappointed, as I've seen several FWD posts that boast 500 DTE at fillup. Some
    of your low MPG could be attributed to new engine break in but not of that magnitude. Something must be wrong, I would definitley make A LOT of noise with your dealer. I have seen several posts that referred to the accelerator sensor (commonly known as the throttle position sensor or TPS) as being out of adjustment, but this is just one possibility. I have included the following list of posts that refer to poor AWD fuel economy. Take these to your dealer. You are not alone and us AWD owners feel your pain, but you shouldn't have to feel THAT much pain. Keep us posted as to the outcome and good luck!!
    Discussion Title Date Author Comments
    Toyota Sienna Gas Mileage #218 08/21/2008 trademarkguru X
    Toyota Sienna Gas Mileage #179 05/09/2008 mleonardo X
    Toyota Sienna Gas Mileage #142 02/06/2008 gmui X
    Toyota Sienna Gas Mileage #141 02/06/2008 gmui X
    Toyota Sienna Gas Mileage #138 02/04/2008 gmui X
    Toyota Sienna Gas Mileage #137 02/02/2008 adeleon1 X
    Toyota Sienna Gas Mileage #131 12/06/2007 oeko X
    Toyota Sienna Gas Mileage #126 11/21/2007 metmdx X
    Toyota Sienna Gas Mileage #47 07/13/2007 beeman4u X
    Toyota Sienna Gas Mileage #44 07/13/2007 beeman4u X
  • dnbqeednbqee Posts: 7
    Its me again, another possibility. Have your dealer reset the PCM (computer). The computer literally learns the driving habits of the driver over many trips, and ressponds accordingly. If your vehicle was only driven by REALLY leadfooted people on test drives, (most people tend to "stomp" on it to check out the power on a test drive.) that could be contributing to your situation. Just a thought. I'm a novice but learning fast! Let us know how it goes.....
  • Thanks. I'll take a look at these posts. I spoke to the dealership and they said to wait until we crack the 1000 mile mark. He said we have lots of hills where we live and it may be that we just get this type of mileage. Not a very good argument.

    We tried a pure freeway test and for 100 miles at 70 mph, we got 14 mpg. Pretty lousy. I put super in just to see if it will make a difference this next time around, but I doubt it.

    I'll try the PCM reset when we go in, and I'll request that they check everything. I told him we could have bought a V8 and gotten better mileage in a large SUV. He did not really disagree. We bought the AWD because the EPA estimates were just 2 mpg off from the 2WD.

    I'll keep you posted, and thanks.
  • Hey Beeman4u - did you ever figure out what was causing your 12 mpg on your Sienna AWD? We have the same problem - 2 weeks old, 800 miles, getting 11 mpg mixed driving and 14 pure highway. Our DTE says 215 on fill up and it's pretty bad. Dealer says to bring it back at 1000 miles.

    When did your mileage open up, and did you ever find out what the problem was? What are you getting now?

    Your insights would be greatly appreciated.

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