The Obsolete Air-Cooled Documentation Project
Progressive Refinements 1940 - 1961

This reference book covers type1/2/3 VW's from 1940 until December of 1961. The book's pages have tables of information that show the incremental changes put in place by Volkswagen during production.

The manual is broken into chapters that cover the main groups common in other VW manuals. Each page has four columns, the first is the date of the change, second is the chassis number of the car that had the change, third is the unit/body number, and fourth is a textual description of the changes.

Dedication

This scanned and uploaded copy of Progressive Refinements, Book 1, is dedicated to the unknown typist or typists of it's pages. Without the painstaking effort to catalog all this information, our knowledge of many of these early VW 'progressive refinements' would be shrouded in mystery.

Indexes
Quick Index

Cover and Production figures

Cover Title N 1/1-1/2 N 1/3-1/4 N 1/5-1/6
N 1/7-1/8 -- N 2/2-2/3 N 3/1 --

Engine, Clutch, and Heating System

Title M 1-2 M 3-4 M 5-6 M 7-8
M 9-10 M 11-12 M 13-14 M 15-16 M 17-18
M 19-20 M 21-22 M 23-24 M 25-26 M 27-28
M 29-30 M 31-32 M 33-34 M 35-36 M 37-38
M 39-40 M 41-42 M 43-44 M 45-46 M 47-48
M 49 -- -- -- --

Fuel System

Title K 1-2 K 3-4 K 5-6 K 7-8
K 9-10 K 11-12 K 13-14 -- --

Front Axle - Steering

Title V 1-2 V 3-4 V 5-6 V 7-8
V 9-10 V 11-12 V 13-14 V 15-16 V 17-18
V 19-20 V 21-22 -- -- --

Rear Axle - Transmission

Title H 1-2 H 3-4 H 5-6 H 7-8
H 9-10 H 11-12 H 13-14 H 15-16 H 17-18
H 19-20 H 21-22 H 23-24 H 25-26 H 27-28
H 29-30 H 31-32 H 33-34 H 35-36 H 37-38
H 39-40 -- -- -- --

Brakes - Wheels - Tires

Title B 1-2 B 3-4 B 5-6 B 7-8
B 9-10 B 11-12 B 13-14 B 15-16a B 16b-17

Frame

Title R 1-2 R 3-4 R 5-6 R 7-8
R 9-10 R 11-12 R 13-14 R 15-16 R 17

Body

Title A 1-2 A 3-4 A 5-6 A 7-8
A 9-10 A 11-12 A 13-14 A 15-16 A 17-18
A 19-20 A 21-22 A 23-24 A 25-26 A 27-28
A 29-30 A 31-32 A 33-34 A 35-36 A 37-38
A 39-40 A 41-42 A 43-44 A 45-46 A 47-48
A 49-50 A 51-52 A 53-54 A 55-56 A 57-58
A 59 -- -- -- --

Electrical System

Title E 1-2 E 3-4 E 5-6 E 7-8
E 9-10 E 11-12 E 13-14 E 15-16 E 17-18
E 19-20 E 21-22 E 22 (cont) E 23-24 E 25-26
E 27-28 E 29-30 E 31 -- --

General Modifications

Title G 1-2 G 3-4 G 5-6 G 7-8
G 9 -- -- -- --
Full Index

Cover and Production Figures

Cover Special Progressive Refinements Cover
Title Special Chassis- and Unit-Numbers (Month End Figures) Title Page
N 1/1 - 1/2 table Type1 production figures (1940-1950)
N 1/3 - 1/4 table Type1 production figures (1951-1954)
N 1/5 - 1/6 table Type1 production figures (REPEAT)
N 1/7 - 1/8 table Type1 production figures (1959-1961)
N 2/1 unknown Type2 production figures (1949-1953). If you have this page contact us!
N 2/2 - 2/3 table Type2 production figures (1954-1961)
N 3/1 table Type3 production figures (1961)

Engine, Clutch, and Heating System

Title Special Engine, Clutch, and Heating System Section Title Page
M 1-2 table 1943-1949
M 3-4 table Aug 1949-Jan 1950
M 5-6 table Jan 16th, 1950 - May 26th, 1950
M 7-8 table Jun 1st, 1950 - Dec 1950
M 9-10 table Jan 4th, 1951 - Nov 26th, 1951
M 11-12 table Nov 26th, 1951 - Jun 10th, 1952
M 13-14 table Jun 18th, 1952 - Nov 1952
M 15-16 table Nov 10th, 1952 - Mar 10th, 1953
M 17-18 table March 1st, 1953 - Oct 7th, 1953
M 19-20 table Oct 14th, 1953 - March 1st, 1954
M 21-22 table Mar 11th, 1954 - Aug 19th, 1954
M 23-24 table Aug 19th, 1954 - Feb 17th, 1955
M 25-26 table Mar 1st, 1955 - Aug 4th, 1955
M 27-28 table Aug 4th, 1955 - May 25th, 1956
M 29-20 table Jun 5th, 1956 - Jan 5th, 1957
M 31-32 table Jan 14th, 1957 - Aug 21st, 1957
M 33-34 table Aug 26th, 1957 - Aug 29th, 1958
M 35-36 table Sept 1958 - May 4th, 1959
M 37-38 table May 12th, 1959 - Oct 2nd 1959
M 39-40 table Oct 9th, 1959 - Apr 11th, 1960
M 41-42 table Apr 26th, 1960 - Aug 5th, 1960
M 43-44 table Aug 5th, 1960 - Nov 24th, 1960
M 45-46 table Dec 1st, 1960 - Jun 16th, 1961
M 47-48 table Jun 15th, 1961 - Dec 4th, 1961
M 49 table Dec 4th, 1961 - Dec 27th, 1961

Fuel System

Title Special Fuel System Title Page
K 1-2 table 1946 - 1951
K 3-4 table Dec 10th, 1951 - May 1st, 1953
K 5-6 table June 14th, 1953 - Aug 4th, 1955
K 7-8 table Sept 10th, 1955 - Jan 21st, 1958
K 9-10 table Jan 22nd, 1958 - Jun 7th, 1960
K 11-12 table Jun 1st, 1960 - Nov 9th, 1960
K 13-14 table Dec 9th, 1960 - Nov 29th, 1960

Front Axle - Steering

Title Special Front Axle - Steering Title Page
V 1-2 table 1945 - Sept 1949
V 3-4 table Nov 1949 - Jun 1951
V 5-6 table Sept 4th, 1951 - May 21st, 1952
V 7-8 table June 16th, 1952 - Mar 10th, 1953
V 9-10 table Mar 7th, 1953 - Nov 11th, 1953
V 11-12 table Nov 21st, 1953 - Mar 1st 1955
V 13-14 table Apr 1st, 1955 - Feb 6th, 1957
V 15-16 table Feb 28th, 1957 - Oct 9th, 1958
V 17-18 table Nov 25th, 1958 - Mar 2nd 1960
V 19-20 table Mar 2nd, 1960 - May 25th 1961
V 21-22 table Jun 30th, 1961 - Dec 5th, 1961

Rear Axle - Transmission

Title Special Rear Axle - Transmission Title Page
H 1-2 table 1946 - May 18th, 1949
H 3-4 table Jun 8th, 1949 - Jan 27th, 1950
H 5-6 table Feb 13th, 1950 - Nov 30th, 1950
H 7-8 table Jan 5th, 1951 - Apr 29th, 1952
H 9-10 table Jun 10th, 1952 - Oct 1st, 1952
H 11-12 table Oct 1st, 1952 - Dec 18th, 1952
H 13-14 table Dec 18th, 1952 - Jul 2nd, 1953
H 15-16 table Jul 1st, 1953 - Sep 15th, 1953
H 17-18 table Oct 3rd, 1953 - Feb 2nd, 1954
H 19-20 table Feb 8th, 1954 - Jun 15th, 1954
H 21-22 table Aug 5th, 1954 - Mar 1st, 1955
H 23-24 table May 11th, 1955 - Aug 2nd, 1956
H 25-26 table Aug 10th, 1956 - Mar 4th, 1957
H 27-28 table Mar 11th, 1957 - Oct 22nd, 1957
H 29-30 table Oct 24th, 1957 - Jun 28th, 1958
H 31-32 table Aug 26th, 1958 - Aug 6th, 1959
H 33-34 table Aug 6th, 1959 - Apr 20th, 1960
H 35-36 table Jan 8th, 1960 - Jun 1st, 1960
H 37-38 table Jun 7th, 1960 - Feb 24th, 1961
H 39-40 table Apr 18th, 1961 - Dec 5th, 1961

Brakes - Wheels - Tires

Title Special Brakes - Wheels - Tires Title page
B 1-2 table 1946 - Jan 3rd, 1951
B 3-4 table Feb 12th, 1951 - Jan 2nd 1953
B 5-6 table Mar 5th, 1953 - Mar, 24th 1954
B 7-8 table May 3rd, 1954 - Mar 1st 1955
B 9-10 table Mar 1st, 1955 - Oct 8th, 1956
B 11-12 table Oct 10th, 1956 - Feb 8th, 1957
B 13-14 table Feb 12th, 1957 - Oct 22nd, 1957
B 15-16a table Nov 1st, 1957 - Aug 1st, 1960
B 16b-17 table Jun 15th, 1960 - Oct 13th, 1961

Frame

Title Special Frame Title Page
R 1-2 table Aug 3rd, 1940 - Nov 1940
R 3-4 table Feb 10th, 1950 - Jan 17th, 1951
R 5-6 table Feb 9th, 1951 - Oct 1st, 1952
R 7-8 table Oct 1st, 1952 - Mar 5th, 1953
R 9-10 table Mar 20th, 1953 - Mar 1st, 1955
R 11-12 table Mar 5th, 1955 - Aug 1st, 1957
R 13-14 table Dec 2nd, 1957 - Dec 8th, 1958
R 15-16 table Jan 6th, 1959 - Jan 16th, 1961
R 17 table July 31st, 1961 - Oct 10th, 1961

Body

Title Special Body Title page
A 1-2 table 1946 - Jun 2nd, 1949
A 3-4 table Jul 1949 - Feb 1950
A 5-6 table Mar 6th, 1950 - Aug 2nd 1950
A 7-8 table Aug 5th, 1950 - Feb 20th, 1951
A 9-10 table Mar 27th, 1951 - Aug 13th, 1951
A 11-12 table Aug 14th, 1951 - Apr 21st, 1952
A 13-14 table May 13th, 1952 - Oct 1st, 1952
A 15-16 table Oct 1st, 1952 - Jan 2nd, 1953
A 17-18 table Jan 2nd, 1953 - Mar 20th, 1953
A 19-20 table Apr 1953 - Sep 7th, 1953
A 21-22 table Sep 15th, 1953 - May 25th, 1954
A 23-24 table May 25th, 1954 - Mar 1st, 1955
A 25-26 table Mar 1st, 1955 - Aug 4th 1955
A 27-28 table Aug 4th, 1955 - Jan 14th, 1956
A 29-30 table Jan 19th, 1956 - Jun 18th, 1956
A 31-32 table Jul/Sep 1956 - Dec 1st, 1956
A 33-34 table Dec 1st, 1956 - May 29th, 1957
A 35-36 table Jun 18th, 1957 - Sep 16th, 1957
A 37-38 table Nov 14th, 1957 - Feb 17th, 1958
A 39-40 table Mar 3rd, 1958 - Jul 31st, 1958
A 41-42 table Jul 31st, 1958 - Dec 1st, 1958
A 43-44 table Jan 8th, 1959 - Jul 6th, 1959
A 45-46 table Jul 17th, 1959 - Aug 6th, 1959
A 47-48 table Aug 6th, 1959 - Aug 28th, 1959
A 49-50 table Aug 29th, 1959 - Feb 10th, 1960
A 51-52 table Mar 8th, 1960 - Aug 1st, 1960
A 53-54 table Aug 1st, 1960 - Nov 18th, 1960
A 55-56 table Nov 21st, 1960 - Apr 28th, 1961
A 57-58 table May 4th, 1961 - Jul 21st, 1961
A 59 table Aug 23rd, 1961 - Dec 14th, 1961

Electrical System

Title Special Electrical System Title page
E 1-2 table May 6th, 1949 - Dec 1st, 1951
E 3-4 table Feb 11th, 1952 - Oct 1st 1952
E 5-6 table Oct 1st, 1952 - Jan 2nd, 1953
E 7-8 table Jan 2nd, 1953 - Dec 21st, 1953
E 9-10 table Dec 21st, 1953 - Oct 18th, 1954
E 11-12 table Nov 1st, 1954 - Aug 4th, 1955
E 13-14 table Aug 9th, 1955 - Aug 20th, 1956
E 15-16 table Aug 21st, 1956 - Jan 23rd, 1957
E 17-18 table Mar 13th, 1957 - Oct 16th, 1957
E 19-20 table Oct 19th, 1957 - Dec 18th, 1958
E 21-22 table Dec 29th, 1958 - Aug 6th, 1959
E 22 (cont) table Aug 6th, 1959
E 23-24 table Aug 6th, 1959 - Mar 14th, 1960
E 25-26 table May 1st, 1960 - Aug 1st, 1960
E 27-28 table Aug 1st, 1960 - Nov 18th, 1960
E 29-30 table Jan 12th, 1961 - Aug 21st, 1961
E 31 table Oct 4th, 1961 - Dec 13th, 1961

General Modifications

Title Special General Modification Title
G 1-2 table 1942 - Jun 27th, 1951
G 3-4 table Sep 24th, 1951 - Jul 15th, 1955
G 5-6 table Aug 4th, 1955 - Jan 1st, 1959
G 7-8 table Jan 2nd, 1959 - Jun 30th, 1961
G 9 table Jul 31st, 1961 - Dec 15th, 1961
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