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Thread: Understanding vehicle efficiency, and its effect on payload

  1. #1
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    Default Understanding vehicle efficiency, and its effect on payload

    I did a technical study on this topic just over a year ago, but thought some of you would enjoy the analysis.

    Topic: Expedition Vehicle Fuel Consumption Rates and its impact on GVWR


    Given all vehicles listed were completing a 1000 mile expedition fully self supported, in which all vehicles attained EPA city mileage. The 5gallon Jerry Can requirement is based upon all of the vehicles having the same sized gas tank as the Tacoma 6cyl Xtra Cab. The Tacoma 6cyl is the reference vehicle.


    Reference:
    Unleaded/Petrol Fuel: 6lbs per U.S. Gallon
    Total Gallons Required= 1000 (miles traveled) / EPA (City) Mileage


    Results:



    Vehicle EPA (City) | Total Gallons | Fuel Mass | Mass Variance | 5gal Cans Req.
    Tacoma 6cyl 17 | 59 Gal | 354 lbs. | Reference | reference
    Suzuki Sidekick 22 | 45 Gal | 270 lbs. | -84 lbs | -3
    Tacoma 4cyl 18 | 56 Gal | 336 lbs. | -18 lbs | -1
    Tundra V8 15 | 67 Gal | 402 lbs. | 48 lbs | +2
    Land Cruiser 13 | 77 Gal | 462 lbs. | 108 lbs | +4
    Discovery II 13 | 77 Gal | 462 lbs. | 108 lbs | +4
    Hummer H2 8.5 | 118 Gal | 706 lbs. | 352 lbs | +12


    Payload Comparison (lbs.):

    Vehicle | Payload | Fuel as a % of payload | Payload Remainder
    Tacoma 6cyl | 1,585 | 22% | 1,231
    Suzuki Sidekick | 898 | 30% | 628
    Tacoma 4cyl | 1,630 | 21% | 1,294
    Tundra V8 | 1,525 | 26% | 1,123
    Land Cruiser | 1,470 | 31% | 1,008
    Discovery II | 1,600 | 29% | 1,138
    Hummer H2 | 2,200 | 32% | 1,494


    General Conclusions:
    - Available payload is a must greater factor than MPG in this study, unless fuel cost, or environmental impact is considered. For example, the H2 Hummer uses nearly 40% more fuel than any other vehicles in the study, but it also has the highest Payload Remainder.
    - The vehicles at the two extremes (Hummer and Sidekick) both had fuel payloads over 30% of available payload capacity
    - The Tacoma proved to be the most frugal selection, using much less fuel, while still having a high Payload Remainder.
    - The Discover II also did well in the Payload Remainder, but suffers from poor economy based on the size of the vehicle.
    Last edited by Scott Brady; 10-20-2005 at 01:54 PM.
    Scott Brady
    Overland Journal
    D1 | LJ78 | LR4 | MKIII | J8 | G-Wagen | Range Rover Classic | TE630

  2. #2
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    Are you using sticker mpg or estimated for modified vehicles? I think I'll try and put some numbers together for an Xterra, Pathfinder, and a Frontier to see how they rate.
    Peace and Mud,
    Patrick, Cyndi, Genavieve, & Rhyse
    www.nissanoffroad.net

  3. #3
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    Quote Originally Posted by The BN Guy
    Are you using sticker mpg or estimated for modified vehicles? I think I'll try and put some numbers together for an Xterra, Pathfinder, and a Frontier to see how they rate.
    Cool! I used MFG sticker MPG for city.
    Scott Brady
    Overland Journal
    D1 | LJ78 | LR4 | MKIII | J8 | G-Wagen | Range Rover Classic | TE630

  4. #4
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    Scott, You seem to know a lot about this and great topic, BTW. My question is in reference to the payload. Are you finding variences in manufacturers in regards to wheather the max payload includes the fuel supply as to not included?

    I just never thought to include the fuel quanity in my tank to figure out the max payload I could load. I am relating this to flying as well, but with flying it is much easier to determin the quantity of fuel you have on board. Also the manufactures have different weights for "wet" and "dry" configurations. So, with that said, I to am assuming that the payload doesn't include oil's as well. Am I correct?

    I guess it is time to pull out the good old owners manual and find out for my self.

    WIL
    Wil Kuhns KF7CDH
    Sierra Expeditions *Forum Sponsor* 866.507.4254
    The only regrets in life are the risks you didn't take.
    Mod Progress Gauge:[||||||----] = 60% Complete.

  5. #5
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    Wil,

    Payload is typically determined as GWV - Curb weight. Curb weight is determined as the weight of the vehicle in stock form with an average driver (175 lbs, IIRC) plus a full tank of gas.
    Nathan Hindman
    Discover the world
    http://www.pangaea-expeditions.com

  6. #6
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    Quote Originally Posted by pangaea
    Wil,

    Payload is typically determined as GWV - Curb weight. Curb weight is determined as the weight of the vehicle in stock form with an average driver (175 lbs, IIRC) plus a full tank of gas.
    BINGO! Exactly what I was looking for thanks!
    Wil Kuhns KF7CDH
    Sierra Expeditions *Forum Sponsor* 866.507.4254
    The only regrets in life are the risks you didn't take.
    Mod Progress Gauge:[||||||----] = 60% Complete.

  7. #7
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    Austin, Tx
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    Quote Originally Posted by expeditionswest
    I did a technical study on this topic just over a year ago, but thought some of you would enjoy the analysis.

    Topic: Expedition Vehicle Fuel Consumption Rates and its impact on GVWR


    Given all vehicles listed were completing a 1000 mile expedition fully self supported, in which all vehicles attained EPA city mileage. The 5gallon Jerry Can requirement is based upon all of the vehicles having the same sized gas tank as the Tacoma 6cyl Xtra Cab. The Tacoma 6cyl is the reference vehicle.


    Reference:
    Unleaded/Petrol Fuel: 6lbs per U.S. Gallon
    Total Gallons Required= 1000 (miles traveled) / EPA (City) Mileage


    Results:



    Vehicle EPA (City) | Total Gallons | Fuel Mass | Mass Variance | 5gal Cans Req.
    Tacoma 6cyl 17 | 59 Gal | 354 lbs. | Reference | reference
    Suzuki Sidekick 22 | 45 Gal | 270 lbs. | -84 lbs | -3
    Tacoma 4cyl 18 | 56 Gal | 336 lbs. | -18 lbs | -1
    Tundra V8 15 | 67 Gal | 402 lbs. | 48 lbs | +2
    Land Cruiser 13 | 77 Gal | 462 lbs. | 108 lbs | +4
    Discovery II 13 | 77 Gal | 462 lbs. | 108 lbs | +4
    Hummer H2 8.5 | 118 Gal | 706 lbs. | 352 lbs | +12


    Payload Comparison (lbs.):

    Vehicle | Payload | Fuel as a % of payload | Payload Remainder
    Tacoma 6cyl | 1,585 | 22% | 1,231
    Suzuki Sidekick | 898 | 30% | 628
    Tacoma 4cyl | 1,630 | 21% | 1,294
    Tundra V8 | 1,525 | 26% | 1,123
    Land Cruiser | 1,470 | 31% | 1,008
    Discovery II | 1,600 | 29% | 1,138
    Hummer H2 | 2,200 | 32% | 1,494


    General Conclusions:
    - Available payload is a must greater factor than MPG in this study, unless fuel cost, or environmental impact is considered. For example, the H2 Hummer uses nearly 40% more fuel than any other vehicles in the study, but it also has the highest Payload Remainder.
    - The vehicles at the two extremes (Hummer and Sidekick) both had fuel payloads over 30% of available payload capacity
    - The Tacoma proved to be the most frugal selection, using much less fuel, while still having a high Payload Remainder.
    - The Discover II also did well in the Payload Remainder, but suffers from poor economy based on the size of the vehicle.
    So how does a sportsmobile stack up... They have a big gas tank, diesel, and hella payload in the 1 ton...
    2013 Jeep Wrangler unlimited lifted and line-x'd with many other toys
    Current Passion - Rugged Individual Outdoor Gear Review Site

  8. #8
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    Could not find any payload capacities other taan cu.ft. for the Xterra and Pathfinder.

    Here's what I found...

    Vehicle EPA (City) | Total Gallons | Fuel Mass | Mass Variance | 5gal Cans

    Frontier 15 | 67 Gal | 402 lbs. | 48 lbs. | +2
    Pathfinder | 15 | 67 Gal. | 402 lbs. | +2
    Xterra 16 | 62.5 Gal. | 375 lbs. | 31 lbs. | +3

    Payload Comparison (lbs.):

    Vehicle | Payload | Fuel as a % of payload | Payload Remainder
    Frontier|1482| 27% | 1080
    Pathfinder N/A----------
    Xterra N/A-----------


    I'm quite bummed about the inability to compare the X and Pathy! But good to see how the Frontier performed. Now I have a 2000 and those numbers are not available but I figure my mileage is a little lower - more along the lines of 'Cruiser considering the mod's I've made.
    Peace and Mud,
    Patrick, Cyndi, Genavieve, & Rhyse
    www.nissanoffroad.net

  9. #9
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    Location
    san diego
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    Here's where my Grand Cherokee stacks up...not great i suppose, but she'll have to do!


    Vehicle | EPA (City) | Total Gallons | Fuel Mass | Mass Variance | 5gal Cans
    Jeep Grand Cherokee (WJ - 4.0L) | 15 | 66.6 Gal | 400 lbs. | 46 lbs. | +2


    Vehicle | Payload | Fuel as a % of payload | Payload Remainder
    Jeep Grand Cherokee (WJ - 4.0L) |1430| 28% | 1030
    David

    '04 4.0L 4x4 Grand Cherokee - 4" spring/spacer lift, Bilstein 5150's, 255/70/16 BFG AT's, OME SD40, disco's, skids, hooks, sliders...and a new ECTED locker

  10. #10
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    Hey +, what about the old Cherokee's?
    Peace and Mud,
    Patrick, Cyndi, Genavieve, & Rhyse
    www.nissanoffroad.net

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