The two entities Liter per 100 km (L/100km ) and Miles per gallon (MPG) ( either US or UK version ) are inversely related.
L/100km * MPG (US) = 235.21 Mnemonics : animal ( 235 ) . net ( 21 )
L/100km * MPG (UK) = 282.48 Mnemonics : uneven ( 282 ) . rarefy ( 48 )
The latter is more easily remembered if you picture the exhaust from an automobile on a rather windless day.
Two more interesting figures:
A. Euler's constant: 2.718 281 182 ... : 718=cut up 281= Neveda 182= fanfare
Who would like to cut up the state of Neveda ?
B. Golden ratio: 1.618 033 988 ... : 618= shed off 033 = mom 988 = puffy face
Even if one doesn't have facial features with golden ratios, it is still a good thing to avoid a puffy face due to edema.
A most memorable telephone no. : 92082138 bans (920) faint (821 ) movie (38)
A few phone numbers with very sensible mnemonic aids :
263-454-52 unjam roller lane
261-403-28 unshod wearisome nephew
235-134-45 animal demure roll
183-528-8 : defame lunar flight foe
366-968-67: magician bashful shock
263-454-52 unjam roller lane
241-829-33 unearth vain boy mummy
274-544-66 anchor leerer cha-cha
360-353-83 matches mileman fame
60-737-417 chase comic reading
269-762-02 unship cushion noah
299-862-62 nabob fashion chain
398-937-80 mob violence beaming face
1 pound = 0.453592 kg / Mnemonics: point* realm ( 453) lib now ( 592)
1 feet = 0.3048 metre /Mnemonics: point* mouse (30) roof (48)
1 horsepower = 745.7 watt /Mnemonics: carol (745) point* cake (7 )
1 mile = 1.609 344 km /Mnemonics: one* point* cheesepie (609) mirror (344)
1 ounce = 28.349523 gram /Mnemonics: navy (28) point* marble (349) liniment ( 523)
1 UK gallon = 4.54609 /Mnemonics: four* point* large (546) Old* (0) bee ( 9)
* My adaptation , not used in the orthodox version of the Major System