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Nissan XTerra Real World MPG



  • The biggest bang for the buck is to reduce wind drag.

    A couple of months ago I decided to test out some of the tangible techniques suggested in a gearhead TV show on improving your gas mileage. I targeted 3 low cost / low risk area: Air Filter, Synthetic Motor Oil, and Roof Rack. I drive a 2007 Nissan Xterra SE (2WD with option of 4WD, V6, 4.0L, 265HP). When the vehicle was brand new, I would get 18-19 mpg city and 24-25 mpg highway @ 55-60 MPH with outdoor temperatures in the 60-80 F degree range. Slightly better gas mileage in the warmer weather than colder winter conditions.

    My vehicle was purchase new (I am original owner). The recommended oil is 5W-30. I drive my Xterra in the Mid-Atlantic region. Mostly in VA, MD, WV. Oil change and scheduled maintenance performed by dealer. Castrol 5W-30 used.

    BEFORE MODs: Before any modifications, my 2007 Nissan Xterra did 18-19 mpg city & 24-25 mpg highway @ 55-60 MPH

    Air Filter: My initial step was to see if the K&N High-Flow air filter would increase my gas mileage (K&N part number for Xterra # 33-2286). Unfortunately my gas mileage did not improve for either city or highway driving. I do need to note that at the time I change my generic Nissan air filter to the K&N high-flow air filter, I kept my Yakima 60" round crossbars and RailGrab mounts on my factory roof rack. By my calculations the Yakima roof rack reduced my gas mileage by about 2 mpg city and 2 mpg highway driving. Since, I was familiar with my gas mileage before, I did want to remove my Yakima rack concurrent with the K&N air filter. So, in short, I did see a any improvement in my mileage with the K&N air filter. I was hoping dramatic improvement in gas mileage per the K&N website "marketing" literature.

    CHANGING OVER TO SYNTHETIC MOTOR OIL: The second step was to test out a high quality fully synthetic oil and oil filter vs. the regular Castrol oil. After researching the grade and brands, I decided to test out Mobil 1 Extended Performance 5W-30 fully synthetic oil. The oil is designed to 15,000 between oil changes. Mobil 1 now has a number of different synthetic oils. The big difference seems to be the interval change. The products come in a 3,500, 5,000, 7,500, and 15,000 miles between oil changes. I went ahead with the Mobil 1 Extended Performance because I found it on sale for about the same price as the regular Mobil 1. I don't think the different products will make much difference. I also installed a Mobil 1 oil filter specifically designed for synthetic oils (part # M1-110). I did not realize how small the 2007 Nissan Xterra oil filter is. Looks like a lawn mower tractor oil filter. Very small. Once again I did not remove my Yakima roof rack when I changed over to the Mobil 1 synthetic oil. I did see any significant change in my mileage. In fact after driving 1,000 miles (mostly highway), my mileage was no better than 17.9 - 18 mpg city and 22 - 22.5 highway at 60-70 MPH. Temperatures ranged in 30 - 50 degrees. So again, I was expecting a big jump, but not much improvement in my gas mileage.

    REMOVING YAKIMA ROOF RACK: After seeing no significant improvement in my gas mileage after installing a K&N high-flow air filter and changing over to synthetic oil, I decided to remove my Yakima roof rack. I could not imagine the Yakima crossbars without any kayak or ski attachments would cause so much drage. But, what the heck. So, this morning I drove the car around without the roof rack, and to my astonishment the mileage improved about 2 mpg city and 2-3 mpg highway driving at 55 MPH. So with the two modifications and removal of my Yakima roof rack, my 2007 Nissan Xterra is getting 19.8 mpg city and 25-26 mpg highway.

    In summary, I conclude the synthetic oil and high-flow air filter improved my gas mileage about 1 to 1.5 miles for both city and highway. I think Nissan incorporated the factory rook rack (and bars) into the cargo box to reduce wind drag. In other words the roof seems pretty streamlined to optimize gas mileage. I did realize how much drag the Yakima crossbars added. I guess when my kayaking season is over, I will remove my other roof accessories from now on. The biggest band for the buck is to reduce your wind drag. In my experience when the cars clean and waxed it gets better gas mileage.
  • steverstever YooperlandPosts: 40,013
    Nice work. I never put much stock in K&N's air filter claims. I don't want to mess with oiling them or worry about them letting too much junk pass through the filter media either.

    I don't boat much anymore so my Yak Racks live in the garage most of the time.

    When our Quest only had ~4,000 miles we did a long road trip and put ~30,000 miles on it, hauling a canoe on top the whole way (78" bars).

    When we got back home, the mpg went down for the next 4,000 miles.

    It only went down a tenth, but for best mpg, don't drive in town. :)

    Need help navigating? - or send a private message by clicking on my name.

  • I've had my Xterra for a few months now. 2007 S model, automatic, no mods, and the roof rack is on. I run 87 octane. My driving is mixed. I seem to average 19-20 at 60 mph. My work drive is on single lane highway with a few stops and occasional passing. I did a couple hour road trip on interstate and got 20.7 at 70 mph. My worst was 17.5, which was mostly in town.
  • chefjeffchefjeff Posts: 1
    Can you or anyone reply with a suggestion on filling up before this test?
    ie. should i fill completely up or begin with half a tank?
    midgrade or premium or bottom dollar fuel is advised?
    I have a 2005 xterra and just recently replaced the cat converter. the vehicle is in great condition with no lights or issues other than its sure thirsty!
    thanks for the consideration.
  • i have a 02 exterra really bad fuel millage high rpm at 65 its around3000 im resetting the ecm as we speak just wondering if i lower the gear ratio if that would help thanks specialed3
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