How Pontiac Works

By: the Auto Editors of Consumer Guide

1964, 1965, 1966 Pontiac Tempest

The 1964 Pontiac Tempest GTO was Pontiac's first "muscle car."

For 1964, GM redesigned all the B-O-P compacts on a 115-inch wheelbase, which made them intermediates. Pontiac's new Tempest wore taut, "geometric" lines on the resulting A-body shared with Chevrolet's new Chevelle, the Oldsmobile F-85/ Cutlass, and Buick's Special/Skylark.

But the real excitement came with the midseason debut of the Tempest GTO, the first "muscle car." That nickname was apt. With the right options, a GTO delivered unprecedented performance for a six-passenger American automobile. Most GTOs were "built" from the order form.


For 1964, you started with a Tempest coupe, hardtop coupe, or convertible, then checked off the GTO option: floorshift, 325-horse 389, quick steering, stiff shocks, dual exhaust, and premium tires, all for about $300. From there you ad-libbed: four-speed gearbox ($188); metallic brake linings, heavy-duty radiator, and limited-slip differential ($75 the lot); 348-bhp 389 ($115). Then all you needed was a lead foot and lots of gas.

Sports-car purists took umbrage at Pontiac's use of GTO, short for gran turismo omologato, the Italian term for an approved production-based racing car. But the outspoken Car and Driver bravely answered them with a mostly on-paper comparison of Pontiac's GTO and Ferrari's GTO. A good Pontiac, they said, would trim the Ferrari in a drag race and lose on a road course. But "with the addition of NASCAR road racing suspension, the Pontiac will take the measure of any Ferrari other than prototype racing cars…The Ferrari costs $20,000. With every conceivable option on a GTO, it would be difficult to spend more than $3800. That's a bargain."

The successful LeMans/Tempest formula saw relatively little change through 1967. Vertical headlights, crisper styling, and three-inch-longer bodies arrived for '65. The '66s had smoother contours, including hopped-up "Coke-bottle" rear fenders and, on coupes and hardtops, "flying buttress" rear roof pillars astride recessed backlights. Standard for the 1967 GTO was a new 400-cid extension of the 389 pumping out 335 bhp; 360 bhp was optional via "Ram-Air," a functional hood scoop.

For 1968 came a redesigned A-body with dual wheelbases: 116 inches on four-doors, 112 on two-doors. Styling borrowed even more big-Pontiac elements such as a large bumper/grille and, on coupes, a more rakish roofline with flush rear window.

Exclusive to GTO was a neatly integrated energy-absorbing front bumper sheathed in color-keyed Endura plastic that resisted dings and dents. One TV commercial pointed out its virtues by showing a group of white-coated Pontiac "engineers" happily hammering the proboscis to absolutely no ill effect.

The midsize Pontiacs continued in this basic form through 1972. Among the mildly facelifted '69s was a hotter GTO: "The Judge," actually an option package with colorful striping, loud paint, a 366-bhp Ram-Air V-8, and three-speed manual gearbox with Hurst floorshift. The 1970s received clumsier front ends, bigger rear bumpers, and pronounced longitudinal bodyside bulges above the wheel openings. The result was a heavier-looking Tempest, GTO, LeMans, and LeMans Sport. Collectors have since tended to prefer the tidier 1964-69 models.

The base engine on 1964-65 Tempests was a 215-cid inline six rated at 140 bhp. For 1966 came a surprising replacement engine, a European-style overhead-cam six developed by Pontiac. Sized at 230 cid, it delivered 165 standard bhp or 207 in "Sprint" guise (via Rochester Quadra-Jet carburetor, hotter valve timing, and double valve springs). The crankshaft had seven main bearings. The camshaft was driven by a fiberglass-reinforced notched belt rather than the usual chain.

With that, the '66 Tempest Sprint was a satisfying performer, if hardly in the GTO's league. It could do 0-60 mph in 10 seconds and reach 115 mph. With options like bucket seats, console, and four-on-the-floor, the clean-lined Sprint had the look and feel of a European grand-touring machine. A longer stroke took the ohc engine to 250 cid for 1968, good for 175 bhp or, in Sprint trim, 215 bhp (230 bhp for '69).

Sadly, it proved less than reliable and, echoing the Tempest four before it, departed after 1969 in favor of a conventional overhead-valve Chevy engine of the same displacement.

For more on the amazing Pontiac, old and new, see:

For more on the amazing Pontiac, old and new, see:

  • Pontiac New Car Reviews and Prices
  • Pontiac Used Car Reviews and Prices