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Can one tell a Prime that a gallon is 4.54 litres not 3.785 liters?

Hi there. If the Prime follows the same functionality as the 48 Series, you could create a user-defined unit of measurement.

Ah.... The prime is assuming a US gallon (3.785411784 L) instead of a UK gallon (4.546092 L) as opposed to a Canadian gallon (4.54609 L). The HP-48 series supported all three "gallon" conversions.

The prime is a US product so it use the US gallon, not the imperial one ;)

Perhaps it's time to use liters ;)

By the way the Prime knows galUS and galUK (and OzUK,ptUK) but I did'nt see canadian gallon.There 23 units of volumes on the Prime

Edited: 26 Aug 2013, 4:37 p.m.

Can one tell a Prime that a gallon is 4.54 litres not 3.785 liters?

Just installed emulator version "Pre-Release 1". The command CONVERT(1_galUK,1_l) gives 4.54609_l

[Edit] PS: If what you meant was "can one redefine 1_gal to be 4.54_l" then no, as this would break programs provided by others.

Edited: 26 Aug 2013, 5:11 p.m.

Perhaps it's time to use liters ;)

I was in school in the U.S. during the mid 1970's and I remember us preparing in earnest to convert to the metric system. It never happened. I think the whole effort can be best summed up by a comedian who said: "We tried the Metric system for a day and it didn't work out.".

As a side note, I am still waiting for the flying cars we were promised would be coming "soon" after the 60's. I'm still a little bitter about that broken promise.

So, this explains why gasoline (petrol) is so expensive in the UK - your gallons are bigger. ;-)


Where did these three gallons come from? The NIST volume conversions site only lists two. Neither match the value for your UK gallon. However, the conversion for the Canadian and UK gallon is tagged exact (bold) however.

- Pauli

They came from converting the three different gallon units to liters using the built-in units on my HP-48SX.

I am still waiting for the flying cars we were promised would be coming "soon" after the 60's

Well, they are "coming soon".

Reserve yours now.

I remember seeing them on the cover of Popular Mechanics when I was about 10. I was so enthralled with the idea I began making plans to build one myself, basically a car with fans on all four corners blowing down for lifting force. I had big plans to use rotating louvers on the bottom of each fan for horizontal movement, steering, etc. Luckily I spent most of my time designing the upholstery pattern for the seat and never got to the point of attaching four lawnmower motors to a frame, adding some propellers and trying to lift off. One of several fortuitous procrastinations that prevented me from leaving this party prematurely. I sure spent a lot of time at school daydreaming about flying around in that thing though!

Thanks for the link, Don. On second thought I totally forgot about what I see on my daily commute on the Los Angeles freeways. I changed my mind. I don't want anybody to have flying cars :(

And what about the video telephone by the turn of the century? Pick up the phone, dial a number and your relative 5000 miles away appears on a TV screen with a perfect view and no delays. In 2013, we are still dealing with 4G and the tiny mobile phones with those jerky videos... What a lie!

Hmmh, ever heard of Skype?


I suspect that's the real reason that it hasn't happened yet! :)

...and why US fuel consumption figures are so poor!

Nigel (UK)

There is no liquid measure called "Canadian gallon". Canada uses Imperial gallons.

Edited: 3 Sept 2013, 12:23 p.m.

True, however Canada adopted the "Standard Imperial Gallon" at 4.54609 litre in 1964. The UK continued to use the "Imperial" gallon at 4.546092 litre until 1985 when they adopted the Canadian convention.