MPG to liters per 100 km conversion chart
 

To make conversions between US / UK measures and European easier, here's a neolithic :-) plot that I just did with figures from an Excel table. Yes, I know I could have done the plot in Excel, but I like doing some things on paper instead: gives me a better "feel" for the figures :-) If you want figures outside this range, here they are (comma is a decimal point, European-style :-)

MPG (US) l/100 km MPG (UK) l/100 km
1 235,20 1 282,48
2 117,60 2 141,24
3 78,40 3 94,16
4 58,80 4 70,62
5 47,04 5 56,50
6 39,20 6 47,08
7 33,60 7 40,35
8 29,40 8 35,31
9 26,13 9 31,39
10 23,52 10 28,25
11 21,38 11 25,68
12 19,60 12 23,54
13 18,09 13 21,73
14 16,80 14 20,18
15 15,68 15 18,83
16 14,70 16 17,66
17 13,84 17 16,62
18 13,07 18 15,69
19 12,38 19 14,87
20 11,76 20 14,12
21 11,20 21 13,45
22 10,69 22 12,84
23 10,23 23 12,28
24 9,80 24 11,77
25 9,41 25 11,30
26 9,05 26 10,86
27 8,71 27 10,46
28 8,40 28 10,09
29 8,11 29 9,74
30 7,84 30 9,42
31 7,59 31 9,11
32 7,35 32 8,83
33 7,13 33 8,56
34 6,92 34 8,31
35 6,72 35 8,07
36 6,53 36 7,85
37 6,36 37 7,63
38 6,19 38 7,43
39 6,03 39 7,24
40 5,88 40 7,06
41 5,74 41 6,89
42 5,60 42 6,73
43 5,47 43 6,57
44 5,35 44 6,42
45 5,23 45 6,28
46 5,11 46 6,14
47 5,00 47 6,01
48 4,90 48 5,89
49 4,80 49 5,76
50 4,70 50 5,65
51 4,61 51 5,54
52 4,52 52 5,43
53 4,44 53 5,33
54 4,36 54 5,23
55 4,28 55 5,14
56 4,20 56 5,04
57 4,13 57 4,96
58 4,06 58 4,87
59 3,99 59 4,79
60 3,92 60 4,71
61 3,86 61 4,63
62 3,79 62 4,56
63 3,73 63 4,48
64 3,68 64 4,41
65 3,62 65 4,35
66 3,56 66 4,28
67 3,51 67 4,22
68 3,46 68 4,15
69 3,41 69 4,09
70 3,36 70 4,04
71 3,31 71 3,98
72 3,27 72 3,92
73 3,22 73 3,87
74 3,18 74 3,82
75 3,14 75 3,77
76 3,09 76 3,72
77 3,05 77 3,67
78 3,02 78 3,62
79 2,98 79 3,58
80 2,94 80 3,53

BTW, the Lupo 3L from Volkswagen was way outside my plot: the manufacturer figure of 3 liters per 100 km (78.4 MPG US) was easily achievable (quite an exception for manufacturer figures :-) :-) A heroic Japanese hypermiler (Shigeru Miyano) set a Guiness Book of Records record by driving this equally heroic little car around the UK, achieving 2.36 l/100 km, or around 100 MPG US. VW order books were overflowing, but the company shut down the production of this particular model of the Lupo within a year or so... I wonder why.... hmmmmm....