1966 Pontiac Mid-Size Cars Fact Sheet
1966 Pontiac Mid-Size Cars Facts, Figures, and Specifications

From the side, the new 1966 Tempest and GTO appeared more bulbous and much larger, however they were the same size as 1965. The new Overhead Cam I-6 engine debuted.
1966 Pontiac Mid-Size Cars – Changes for 1966
Tempests were completely restyled for 1966 with smoother body contours, rounder edges, wider wheel openings., and more prominent recessed split grilles. The rear of the roof line in the 2-door hardtops had “buttresses” attached to the C pillar to give the roof line a more sweptback appearance. The stacked headlamps were retained.
General Year Information – 1966 Pontiac Mid-Size Cars
Tempests were completely restyled with smoother bodies, rounder contours, wider wheel openings, recessed split grilles and stacked headlamps. A new “shadow box” roof line set the two door hardtop coupe apart. Each of four series now had completely distinctive ornamentation.
The really big news for Tempests was under the hood, where the unique overhead camshaft six-cylinder engine was now employed as the base power plant for all except the GTO line. A sporty-looking “Sprint” option package (code W53) was available that mated the new Overhead Cam I-6 engine to a 4-barrel carburetor and making 207 HP. It had a ride and handling package standard – an economical alternative to the GTO.
The GTO line was now a separate series, and no longer an option on the LeMans line.
1966 Pontiac Mid-Size Cars Factoids
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In January 1966 Pontiac began offering Ram Air as a factory option with the “XS” code engine. It included a new camshaft with increased duration going from 288/302 to 301/313 (No. 744) & new valve springs w/dampers. The tri-power equipped XS-code 389 was shipped with the Ram Air pan in the trunk, and the dealer had to fit it and cut out the underside of the hood scoop to make it functional. See a Ram Air Test HERE.
The single overhead camshaft (SOHC) design was the standard engine in the Tempest line. The 230 CID OHC 6 shared internal dimensions with the Chevrolet I-6 engine, but used unique block and head castings. Only the large cam carrier/valve cover was aluminum. The cam was driven by a fiberglass reinforced timing belt. It was offered with a one-barrel carburetor, rated at 165 HP and a W53 4-barrel “Sprint” version that made 207 HP. See the Intodutory Brochure HERE.
1966 Pontiac Mid-Size Cars Facts – Models Offered
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Series 233: Standard Tempest trim included wind split moldings behind front wheel openings, “Tempest” on the rear fenders in script and nylon-faced fabric upholstery with Jeweltone Morrokide accents. 33,143 of the 43,753 base Tempests were equipped with automatic transmissions.
Cars with optional V-8 power were dressed with front fender badges behind the wheel opening displaying “326”.
Series 235: Tempest Custom trim included thin moldings accenting the smooth “Coke bottle” shape. Additionally, there was “Tempest Custom” in script as identification on the rear fenders. Deluxe steering wheels and carpet, were additional standard features over the base car’s features. Convertibles sported courtesy lamps and Morrokide trim.
Cars with optional V-8 power were dressed with front fender badges behind the wheel opening displaying “326”. 83,093 of the 85,674 Tempest Custom vehicles were equipped with automatic transmission.
SERIES 237: LeMans models had special trim that included simulated louvers on the forward edge of front tenders, elongated V-shaped emblems behind front wheel openings and “LeMans” in lettering on the rear fender sides. Standard equipment included Morrokide and cloth trim combinations in four-door hardtops and all Morrokide in others.
Convertibles, hardtops, and sport coupes came with the choice of bucket or notch-back front seats with a folding arm rest. All LeMans had carpeting, front foam seat cushions, lamps for the ash tray, the cigarette lighter and the glove box.Convertibles had a power top.
The GTO option was no longer a part of the LeMans Series.
SERIES 242: The GTO line was now a separate series with distinctive trim on the new Tempest sheet metal. A wire mesh grille insert without horizontal divider bars was used. The grille incorporated rectangular parking lamps, and a “GTO” nameplate on the left-hand side of the opening.
A single scoop appeared on the hood, elongated V-shaped badges were mounted behind the front wheel openings, GTO lettering appeared on the deck lid and rear fenders. The upper belt line contour was pin striped and horizontal twin-slot tail lamps were used.
Standard equipment included all LeMans items plus the 389 CID four-barrel V-8; walnut grain dash panel Inserts; dual exhausts; heavy-duty shock absorbers, springs, and stabilizer bar as well as 7.75 x 14 tires – either redline or whitewall.
1966 Pontiac Mid-Size Cars Facts – Engines
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- 165 HP 230 CID I-6
- 207 HP 230 CID I-6
- 326 CID V-8 250 HP
- 326 CID V-8 285 HP
- 389 CID V8 335 HP GTO
- 389 CID V8 360 HP GTO
- 389 CID V8 360 HP Ram Air GTO
- NOTES
Tempest I-6 – Optional All Transmissions: Overhead valves, overhead camshaft. Cast iron block. Displacement: 230 cubic inches. Bore and stroke: 3.875 x 3.25 inches. Compression ratio: 9.0:1. Horsepower: 165 @ 4700 RPM. Torque: 216 @ 2600 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 228°, Exhaust 228°, Overlap 14°, Lift 0.400″. Carburetor: Rochester one-barrel model (manual transmission) 7026167 (Automatic) 7028168.
Tempest I-6 – All Transmissions: Overhead valves, overhead camshaft. Cast iron block. Displacement: 230 cubic inches. Bore and stroke: 3.875 x 3.25 inches. Compression ratio: 10.5:1. Horsepower: 207 @ 5200 RPM. Torque: 228 @ 2800 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 244°, Exhaust 244°, Overlap 26°, Lift 0.438″. Carburetor: Rochester four-barrel model (manual transmission) 7026167 (Automatic) 7026168.
Tempest Base V-8 – All Transmissions: Cast Iron Block. Displacement: 326 CID. Bore and stroke: 3.72″ x 3.75″ Compression ratio: 9.2:1. Horsepower: 250 @ 4600 RPM. Torque: 333 @ 2800 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 269°, Exhaust 277°, Overlap 47°, Lift 0.370″. Carburetor: Rochester 2-barrel (manual transmission) 7026071 (automatic) 7026062.
Tempest Optional V-8 – All Transmissions: Cast Iron Block. Displacement: 326 CID. Bore and stroke: 3.72″ x 3.75″ Compression ratio: 10.5:1. Horsepower: 285 @ 5000 RPM. Torque: 359 @ 2900 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 269°, Exhaust 277°, Overlap 47°, Lift 0.370″. Carburetor: Carter AFB 4-barrel (manual transmission) 4035S, (automatic) 4036S.
Optional GTO 335 Horsepower V-8 – GTO , All Transmissions: Overhead valves. Cast iron block. Displacement: 389 CID. Bore and stroke: 4.0625″ x 3.750″. Compression ratio: 10.75:1. Horsepower: 335 @ 5000 RPM. Torque: 431 @ 3200 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 273°, Exhaust 289°, Overlap 54°, Lift 0.406″. Carburetor: Carter AFB Model 4033S (manual transmission) 4034S (Automatic).
Optional GTO 360 Horsepower V-8 – All Models , All Transmissions: Overhead valves. Cast iron block. Displacement: 389 CID. Bore and stroke: 4.0625″ x 3.750″. Compression ratio: 10.75:1. Horsepower: 360 @ 5200 RPM. Torque: 424 @ 3600 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 288°, Exhaust 302°, Overlap 63°, Lift 0.409″ (intake) 0.409″ (exhaust). Carburetors: three 2-barrel Rochester carburetors: (front) 7025178, (center manual trans) 7026075, (center auto trans) 7026074, (rear) 7024179.
Optional GTO 360 Horsepower V-8 – All Models , All Transmissions: Overhead valves. Cast iron block. Displacement: 389 CID. Bore and stroke: 4.0625″ x 3.750″. Compression ratio: 10.75:1. Horsepower: 360 @ 5200 RPM. Torque: 424 @ 3600 RPM. Five main bearings. Hydraulic valve lifters. Camshaft Duration: Intake 301°, Exhaust 313°, Overlap 76°, Lift (intake) 0.413″; (exhaust) 0.413″. Carburetors: three 2-barrel Rochester carburetors: (front) 7025178, (center manual trans) 7026075, (center auto trans) 7026074, (rear) 7024179.
NOTE: In January 1966 Pontiac began offering as a factory option the “XS” code Ram Air engine. It included a new camshaft with duration increased from 288/302 (No. 068) to 301/313 (No. 744) and a new valve spring package with dampers to positively control valve action. Valve lift stayed at just over 0.400-inch with 1.5:1-ratio rocker arms. The tri-power equipped XS-code 389 was shipped with the Ram Air pan in the trunk, and the dealer had to fit it and cut out the underside of the hood scoop to make it functional.
More detailed information on the 1966 I-6 and 326 and 389 CID V-8 engines may be found in the Library’s 1966 AMA Pontiac mid-size Specifications Sheets. You may access the sheets HERE, or use the navigation on this page.
1966 Pontiac Mid-Size Cars Facts – Chassis Features
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- Wheelbase: All Tempests: 115 inches.
- Overall length: (Tempest Safaris) 204.6 inches, (Tempest passenger cars) 206.4 inches
- Front track: All Tempests: 58 inches.
- Rear track: All Tempests: 59 inches.
- Standard tires: Standard Tempest: 6.95 x 14; optional 7.35 x 14 mounted on 14 x 5JK rim wheels standard
- Standard tires GTO: 7.75 x 14 Nylon cord red stripe tires mounted on 14 x 6JK rim wheels standard.
- Optional tires GTO: 7.75 x 14 rayon cord white wall
1966 Pontiac Mid-Size Cars Facts – Power Train Options
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- Three-speed manual transmission was standard.
- 165 HP OHC I-6 engine was standard
- Automatic transmission was optional.
- Four-speed manual transmission was optional.
- 207 HP OHC I-6 engine was optional
- 250 HP 326 CID V-8 optional In Tempest, Tempest Custom and Tempest LeMans lines for cars without the GTO option.
- 280 HP 326 CID V-8 optional In Tempest, Tempest Custom and Tempest LeMans lines for cars without the GTO option.
- 335 HP 389 CID V-8 standard & exclusive to the GTO.
- 360 HP 389 CID V-8 Tri-Power was optional on the GTO.
- Heavy-duty 3-speed manual gear box was optional on the GTO
- Close-ratio 4-speed manual box was optional on the GTO.
1966 Pontiac Mid-Size Cars Facts – Significant Options
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- Air-conditioner ($343).
- Bucket seats ($145).
- Carpets ($19).
- Cordova tops ($72-86).
- Custom sports steering wheel ($29).
- Deluxe steering wheel with ring ($15).
- Electric clock ($19).
- GTO option
- LeMans console shift ($48).
- Padded dash ($16).
- Panel cluster and tachometer Rally Gage ($86).
- Parking brake signal ($3).
- Power brakes ($43).
- Power convertible top ($54).
- Power steering ($95).
- Power tailgate window ($54).
- Power tilt bucket seat L.H. ($67).
- Push button radio ($62).
- Push button radio – AM/FM ($137).
- Rally wheels ($36-53).
- Remote control deck lid ($11).
- Ride & Handling package ($16).
- Safari luggage carrier ($65).
- Safeguard speedometer ($16).
- Safe-T-Track positive traction rear ($37)
- Sprint Option Package – 207 HP I-6 & Ride and Handling ($127)
- Super-Life shock absorbers ($40).
- Tachometer ($54).
- Tilt steering wheel with power assist only ($43).
- Two-speed wipers and washers ($17)
- Wheel discs ($20-37).
- White wall tires ($41)
- Wire wheel discs ($54-71).
1966 Pontiac Mid-Size Cars Facts – Body Paint Color Codes
Click on the Paint Code Name to See the Mix Codes for the appropriate color:
1966 Pontiac Mid Size
1966 Pontiac Mid-Size Cars Facts – Current Market Values
- 1966 Pontiac Tempest Valuation Tool
- 1966 Pontiac Tempest Custom
Valuation Tool - 1966 Pontiac Tempest LeMans
Valuation Tool - 1966 Pontiac GTO Valuation Tool
1966 Pontiac Mid-Size Cars Facts – The GTO option package included:
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- The 389 cubic inch high-performance V-8
- Special GTO nameplates for the grille, fenders, deck lid and glove box door.
- Simulated engine-turned aluminum dash panel inserts.
- Single air scoops on the hood.
- Ride and handling package
- See Brochure for List – Click HERE
1966 Pontiac Mid-Size Cars Facts – Powertrain Information
- Three Speed Manual Transmission Ratios
- I-6 1st – 2.85:1, 2nd – 1.68:1, 3rd – 1:1, Reverse – 2.95:1
- V-8: 1st – 2.42:1, 2nd – 1.61:1, 3rd – 1:1, Reverse – 2.33:1
- Four Speed Manual Transmission Ratios
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- V-8 Wide Ratio: 1st – 2.52:1, 2nd – 1.88:1, 3rd – 1.46:1, 4th 1:1, Reverse – 2.59:1
- V-8 Close Ratio: 1st – 2.22:1, 2nd – 1.64:1, 3rd – 1.28:1, 4th 1:1, Reverse – 2.27:1
- V-8 Wide Ratio: 1st – 2.52:1, 2nd – 1.88:1, 3rd – 1.46:1, 4th 1:1, Reverse – 2.59:1
- Automatic Transmission Ratios
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- All: Low – 1.76:1, High – 1:1, Reverse – 1.76:1
- Rear Gear Standard Ratios
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- See Page 4 in the 1966 Pontiac Mid-Size AMA Specifications Sheet for all potential ratios
- See Page 17 in the 1966 Pontiac Mid-Size AMA Specifications Sheet for all standard/optional ratios
NOTE: For more powertrain information, access the 1966 Pontiac AMA Specifications Sheets HERE
1966 Pontiac Mid-Size Cars Facts – Related Document Downloads
Files directly related to the 1966 Pontiac Mid-Size Line will appear below. Click to Download:
1966 Pontiac Performance Brochure
1966 Pontiac Tempest Print Ads
1966 Pontiac Mid-Size AMA Specifications Sheets
1966 Pontiac Sprint Road Test – Car Life Magazine
1966 Pontiac Sprint Road Test – Car and Driver Magazine
1966 Pontiac GTO Road Test – Motor Trend Magazine
1966 Pontiac GTO Road Test – Car Craft Magazine
1966 Pontiac GTO Comparison Road Test – Car and Driver Magazine
1966 Pontiac Mid-Size Cars Facts – Related Images
Related Images to the 1966 Pontiac Mid-Size Line will appear below
1966 Pontiac GTO Convertible
There was no doubt about the flashy, in your face nature of the 1966 Pontiac GTO Convertible. But a hefty price tag allowed only 12,798 to leave the showrooms.
1966 Pontiac GTO Hardtop Coupe
The 1966 Pontiac GTO Hardtop Coupe was the most popular GTO by far, with 73,785 sold, making it the 2nd most popular mid-size.
1966 Pontiac GTO 2-door Sports Coupe
If you wanted maximum performance from your GTO, the 1966 Pontiac GTO 2-door Sports Coupe was your ticket. Surprisingly only 10,363 were produced.
1966 Pontiac LeMans Convertible
The 1966 Pontiac LeMans Convertible was the upscale drop top for those not wanting GTO power. 13,080 were sold.
1966 Pontiac Le Mans 4-door Hardtop
The 1966 Pontiac Le Mans 4-door Hardtop was the top of the line 4-door. It sold moderately at 13,897 produced.
1966 Pontiac LeMans 2-door Hardtop
Sitting just under the convertible as a sporty offering, the 1966 Pontiac LeMans 2-door Hardtop was the most popular mid-size Pontiac with 78,109 delivered.
1966 Pontiac LeMans 2-door Sports Coupe
The 1966 Pontiac LeMans 2-door Sports Coupe was the less expensive, but just as sporty version of the the hardtop. 16,654 were purchased.
1966 Pontiac Tempest Custom convertible
The 1966 Pontiac Tempest Custom convertible was the entry level mid size convertible in 1966. People wanted more flash in their drop top, so only 5,557 were sold.
1966 Pontiac Tempest Custom 4-door Hardtop
The 1966 Pontiac Tempest Custom 4-door Hardtop was moderately popular with 10,996 sold.
1966 Pontiac Tempest Custom 2-door Hardtop
The 1966 Pontiac Tempest Custom 2-door Hardtop was sporty and less expensive than the LeMans. As a result 31,322 were delivered.
1966 Pontiac Tempest Custom 4-door Sedan
The 1966 Pontiac Tempest Custom 4-door Sedan was a popular upscale sedan offering. 23,988 were delivered.
1966 Pontiac Tempest Custom 2-door Sports Coupe
1966 Pontiac Tempest Custom 2-door Sports Coupe sold better than expected, but not as well as the lesser base model. However, 17,182 were purchased.
1966 Pontiac Tempest Custom Station Wagon
The 1966 Pontiac Tempest Custom Station Wagon was a bit upscale in interior trim and other options over the base wagon. 7,614 were produced.
1966 Pontiac Tempest 4-door Sedan
The 1966 Pontiac Tempest 4-door Sedan was an inexpensive alternative to great transportation and 17,392 were produced.
1966 Pontiac Tempest 2-door Sports Coupe
The 1966 Pontiac Tempest 2-door Sports Coupe was surprisingly popular with 22,266 delivered.