Over the six years of manufacture, the factory was constantly updating the 912.  Owners could also create a unique 912 by specifying numerous options offered.  Following are numerous changes in the evolution of the 912/912E (click for a table of original specifications or a list of 912 books).  Features should be considered individually; an original car may not have all the features listed in a yearly group below.

The original 912.  Short wheel base (SWB), glass covered headlights, sealed turn signal units, chrome or painted 4 1/2" x 15" steel wheels with caps, four-wheel disc brakes, Nadella half-shafts, 356-style aluminum bumper and rocker trim, small round Durant side mirror, silver wiper arms, angles 912 script, operable vent windows, green-on-black faced three gauge instrument cluster, 356-style painted dash matching exterior (on very early cars), 356-style unmarked shift knob, 356-style map pockets full length of doors, rubber floor mats front and rear, heater control forward of gearshift, white sun visors.  "Safety Steering" jointed steering mechanism with three short column links (including one angled intermediate shaft) connected to a rack and pinion box.  4 cylinder boxer, 1582cc, compression 9.3:1, output 90 DIN (102 SAE) hp/5800 rpm.   Pushrods and rocker arms.  Cogwheel camshaft drive.   Forged crankshaft with 4 main bearings, pressure lubrication.  Mechanical fuel pump, 2 double downdraft Solex carburetors.  Right-hand drive available.

6,401 1965 912s were produced.  Factory options: five-speed racing pattern transaxle, hillclimb gears, right-hand drive, five gauge instrument cluster, chrome bumper guards, three-point seat belts, 356-style roll headrests bolting onto rear of seatback, Hella 128 fog lights, rear window wiper, sunroof, luggage straps, wood-rim steering wheel, special colors.

Very similar to 1965 912.  Revised air cleaners, black dashboard with brushed aluminum trim, easier-to-fill windshield washer bottle.  Overall for 1966, Porsche produced 9,090 912s.

Factoid: Colors of Porsches delivered in 1966, by percentage of overall production [as indicated in the October 1967 Christophorus]
Light Ivory (23.9%), Polo Red (18.7), Irish Green (14.2), Aga [dark] Blue (8.7), Gulf [light] Blue (4.6), Sand Beige (9.5), Slate Grey (6.9), Bahama Yellow (6.5), Metallic Silver (3.1), Black (3.0), other colors (0.9)

Revised half-shafts with Lobro constant velocity joints.  Revised motor mounts dampened engine vibrations for lower noise levels.  Five gauge instrument cluster standard, round shift knob with shift pattern, black and white sun visors on coupes, Perlon carpets.  Targa model available, with soft-window standard, stainless steel Targa bar.   Optional Fuchs 4 1/2" x 15" alloy "windmill" wheels, rubber strips for chrome bumper guards.  Many historical racing organizations use 1967 as a cutoff, making 1967 a popular 912 racecar year.

New safety regulations in the United States certainly had an influence of the modifications made in 1968.  Dual-circuit brakes were standard, along with uncovered headlights with larger chrome rims, door handles with recessed buttons, a larger Durant side-view mirror, white-on-black faced gauges, a break-away windshield mirror mounted to the window frame, rubber covers on control knobs, door cranks, vent locks, attachment pints for rear seat belts.  Black wiper arms.  Two-piece reflection-free dashboard allowing massive deformation in an accident.  Halogen lamped Hella 128 fog lights.  In the U.S. reflective side markers were mandatory.  U.S. emissions requirements including vacuum advance distributor, air pump, and split-shaft Solex carbs.  A larger generator (420 watt) charged the battery faster.  Mid-year, the hard-window Targa becomes standard, and the soft-window optional.  Wider rims (5 1/2") giving enlarged tire contact, optional Fuchs 5 1/2" x 15" alloy "windmill" wheels.

Like the 356, and its A, B, and C variations, the factory drew distinctions in the 911/912 series.  But unlike the 356 series, this time the factory used the designations internally.  Based on experience with the 911/912 including racing, the factory made enough changes to warrant an internal 911/912-B designation for the 1969 model.  This is also known as the long wheel base (LWB) revision.

To improve handling without penalizing ride, the rear wheels of the LWB version moved back 2.5", with no change in overall vehicle length.  Revised turn lights with illuminated side markers, with removable lenses.  Slightly flared front and rear wheel wells.   Revised dashboard with new ventilation and controls, revised arm rests and door pockets, rear-view mirror mounted to the windshield.  The battery location was moved under the headlight bucket.  Seats designed for optional adjustable headrest mounting directly into seatbacks.  The rear windows in the coupes were electrically heated, eliminating air ducts.  Fixed vent windows on coupes, vent slots appeared on the stainless steel Targa bars.  Optional Fuchs 6" x 15" alloy "windmill" wheels, Hella 169 fog lights.

In the U.S., the emission control air pump was not needed to pass regulations, due to refinements such as specially-coated intake manifolds.  The Porsche factory advertisement "Fact Book" notes a slight increase to 103 horsepower (SAE).

AKA Type 923, the 912E is the last Porsche model powered by a four-cylinder, air-cooled engine.  The factory produced 2099, delivered primarily to North America.

With a seven year gap in 912 production, the 912E uses the "I-series"  911/912 chassis.  For 1976 the factory began zinc coating the basic chassis unit, although due to limited availability not all cars received the treatment.  A 2.0 fuel injected engine built of 914 engine components powers the 912E.  Other changes include a 923/02 transaxle, energy-absorbing bumpers, 21 gallon fuel tank; revised steering rack; revised seats, steering wheel and mirrors, ATS "cookie-cutter" alloy wheels.

Would you prefer owning one of the earliest existing 912s, or one of the very last made?  How about one with a rare feature or option?  Concours rules notwithstanding, if you like an early car but also want a particular features from later years, also consider that many parts are interchangeable.  For example, an owner less concerned about originality could, for example, modify numerous 912 suspension components.   Consider keeping the old parts just in case (like those soft-window Targa parts to be removed when an owner installs a glass rear window).

912 owners don't need the latest sports car, only his or her favorite 912(s).  Then again, consider the adage "If you really like something, buy two; some day they will stop making them."