us or uk gallon

Discussion in 'American RV's' started by smudger, Mar 16, 2011.

  1. smudger

    smudger Funster

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    hi guys....can any body tell me the difference between an american gallon and a uk gallon..
    reason i,m asking is,...when i bought my rv, off winnibago, it said in the brochure,that it done about 12 miles to the gallon. but ive been told that the uk gallon is bigger than the u.s.a. one. if that is so,then i,m getting more than 12 miles to the gallon......is that correct. it has been said that i,m getting about 17 mpg....and the chap who claimed this who will remain annoyminos for now....i tend to beleive him..he stands by this...dont you roger....now before you answer.i went to caterpillar in cannock, and they road tested the vehicle,on the m6.motorway, and claimed that at 75mph,my engine was using 5,7.ltrs an hour....and at 54 mph, 5.9 ltrs an hour. so slower you go,the more you use, when i questioned it with the testing guy, he said, these engines are designed to perform at there peak revved out.....so what do you reckon,...am i getting more mph for my buck, (euro dollar)or is it a load of bull.:Smile:
     
  2. jhorsf

    jhorsf Read Only Funster

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    Since one US gallon is equal to 0.833 Imperial gallons, use this formula:

    1. US gallons x 0.833 = Imperial gallons


     
  3. jhorsf

    jhorsf Read Only Funster

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    Last edited: Mar 16, 2011
  4. Snowbird

    Snowbird Funster Life Member

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    I would say the Cat man was right. Depending on the gearing,big engines are designed to run at a certain RPM to give the best fuel economy.If he road tested it with his laptop attached then he should have the best figures.My Cummins runs better at 60 MPH than 55MPH and gives a better fuel economy at 60 as it tends to labour a bit at the lower speed.Have always said that this business of every vehicle runs at its most economical at the same speed is bull**** as speed has nothing to do with economy its RPM that dictates that. I once had a Scania 141 that ran best at 64 MPH,but that was before the days of speed limiters.:Eeek:
     
  5. simsy56

    simsy56 Funster

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    1 UK gallon=1.2 US gallons.


    Craig
     
  6. motor roamin

    motor roamin Funster

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    Because my brain aint too good I always work it out 6uk pints to one US gallon near enough for me, although I know what my RV does to the gallon I never want to work it out other than for curiosity, I know my engine is a lot ceaper on diesel than my genny :cry:

    All the best Rick
     
  7. simsy56

    simsy56 Funster

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    If you achieved 12 per US gallon that would equal 14.4 per UK gallon.

    Craig
     
  8. motor roamin

    motor roamin Funster

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    And had a switch installed afterwards :Rofl1: :Rofl1:

    I completley agree with snowbird, all down to RPM.

    All the best Rick
     
  9. Snowbird

    Snowbird Funster Life Member

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  10. Geo

    Geo Trader - Funster

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    You will excuse my sceptical engineering brain here:RollEyes:
    Lets say we agree RPM is what consumes fuel:thumb:
    your engine MUST do more RPM to do 75 than it does to do 54 :Doh:
    Me thinks Cat man needs to stick to smoking normal cigs:Rofl1::Rofl1::Rofl1:
    Professor Geo PHG
    (Pecks Hill Garage):RollEyes:
     
  11. Snowbird

    Snowbird Funster Life Member

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    All to do with engine loading and gearing Geo.
     
  12. slobadoberbob

    slobadoberbob Read Only Funster

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    Yes that is right

    If I purr along at 55 mph I am doing 1800 rpm... If I push it up to a higher speed the rev's increase and so does the mph.. Ipso facto it has to use more fuel to move the same mass.

    Mine is very happy anywhere under 2,000 rpm.. But remember I am using petrol and not diesel.. V 10 6.8 .. All up 5.5 tons... (2,000 rpm... Gets me to 60 mph ....fast enough for me in an RV)

    Bob
     
  13. Geo

    Geo Trader - Funster

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    Sorry my ole mate
    Whilst I except you can change gear :Rofl1:
    you cant change phisics:Doh:
    Not even from my mentor Rick will I except that statment and we normally agree on 99.9%
     
  14. Forestboy

    Forestboy Funster Life Member

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    Have to agree with Geo:Doh:
    I've had 3 different RVs diesel and petrol and one thing they all had in common the faster I went the more fuel they used.

    Best economy ever was in the diesel from Edinburgh to Ross on Wye motorway all the way except 40 miles. Running at 55mph it averaged 15mpg and I was tucking in behind larger artics to get the benefit. The same Rv at anything over 60mph was down to 9.5 mpg or less. I did 30000 in that Rv and the economy (or lack of) was always the same.

    With the price of diesel I can't see any benefit over petrol in a RV and the petrols drive so much nicer.:thumb:
     
  15. Snowbird

    Snowbird Funster Life Member

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    OK lets look at it this way...Take two identical coach chassis with the same engine but one is geared for a town bus,pottering along at 30 to 40 MPH.
    The other is geared for motorway use cruising at 60 to 65 MPH.
    If you swopt jobs and put the town bus on the motorway job and the highway bus on the town job do you think they would both give the same consumption???.The town bus would be working flat out to maintain motorway speeds and the highway bus would never reach its designed working speed.Premium trucks are now running at 600 BHP plus and the reasoning behind this is that they are capable of running more economically than a smaller engine which is under load all the time.
    Am certainly no engineer but do know more than a little about about fuel economy as my living depended on fuel economy all my working life.
    When the difference of profit and loss comes into the equation you have no choice but to know.:thumb:
     
  16. Wildman

    Wildman Read Only Funster

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    only real way to check it is full tank to full tank over a decent distance. when I calculated 17mpg it was a very rough calculation based on the amount of fuel put in the tank over a distance measured on a map rather than off the speedo. but must admit to being very surprised. Meaured properly I would not be surprised to see 15mpg being recorded.
     
  17. DBSilverfox

    DBSilverfox Read Only Funster

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    When I was in the US 2 weeks ago I recall the urinals all said 3.8 litres / 1 gallon per flush.

    did not seem important to be told that at the time I was standing there, but actually now I get the opportunity to share :Rofl1:

    so now you also have the litre equivalent

    David
     
  18. JJ

    JJ Funster

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    Some questions to all you clever engineer chappies..

    Does wind resistance play a part in fuel consumption?

    Does wind resistance increase the faster you travel?

    If the answer to the questions above is "yes"

    Question 3. Does any advantage in consumption gained by increasing the revs to make the engine more efficient (and thus increasing the speed if kept in the same gear) get more than wiped out by the increase wind resistance?

    JJ :Smile:


    Given that Smudger's Monster (RV) has the aerodynamics of a giant, flat faced brick being pushed through lard I would reckon the best course of action would be to park up, cook a pie, open a beer and relax :Rofl1::Rofl1::Rofl1:
     
  19. Dodgey

    Dodgey Funster

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    Good morning JJ, and love it:Rofl1::Rofl1::Rofl1::Rofl1:
     
  20. Snowbird

    Snowbird Funster Life Member

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    As the honorable JJ has pointed out there are many factors to be taken into account regarding fuel consumption,ie terrain,wind direction,driver,load carried, etc.
    Going back to the OP if I may...his RV has a Caterpillar engine,I know not what size it is but would assume its somewhat larger than your average Fiat 2.5 or even the Chevy 6.5.
    The Cat engine was regarded as a bit of a guzzler a few years ago as its main use was in earth moving equipment,but it has now got a large following in the haulage and RV market as they have found that it revs harder and because of modern computer diagnostics can be tuned for more economical use in more applications.
    Have actually been to Finnings at Cannock to have a truck tuned by them and was amazed at the way they do the diagnostics.All high tech stuff.They can set up a diesel engine for whatever application the vehicle is being used for ie motorway,urban or even trucks running out of the Peak District.
     

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