by John Ethridge, Technical Editor
Y TRADITION and also by size, weight, interior appointments, accessories, and ride, the Pontiac Grand Prix is a personal car. But when it comes to acceleration, the 1965 GP narrowly misses being in the performance-car category.
Three things account for its off-the-line performance: 1) the built-in porting job on the engine that lets it breathe deeply and crank out solid power; 2) the three-speed automatic transmission with its well chosen ratios, which allows you to control shift points to get the most from the engine; and 3) the swept-hip perimeter frame that lops some 300 pounds off the weight of the last GP we tested. The test car's 3.08-to-1 axle ratio is by no means the best for acceleration, and we feel the car would easily break into performance times with a numerically higher ratio.
Bear in mind that our GP's 325-hp V-8 is the least powerful engine offered in this car. Others put out 338, 356, and 376 hp, the last two being Pontiac's 421 cubic-inchers. It's not that we're recommending more power, because the 325-hp engine is obviously quite ample.
The GP's a real sleeper in the way it goes. It's so smooth and quiet that, without test instrumentation, we weren't aware that performance was nearly this good. Our acceleration times were effortless and easily repeatable.
The Turbo Hydra-Matic three-speed automatic can be used as a set-it-and-forget-it, or you can shift it yourself. They've designed it for maximum driver control—when you want it. There's a noticeable improvement in acceleration times when shifting manually, and we wrung out those recorded in the performance table that way. It's very quiet when idling with the selector in the N position, because everything inside the transmission stops except the converter and the fluid pump, You can downshift from D all the way to L at, say, 100 mph, but the transmission won't select SECOND and LOW until the engine reaches proper speeds. Thus, you can get maximum engine braking without any danger of locking the rear wheels.
Pontiac engineers describe this transmission as "fool-proof but not idiot-proof." They don't recommend you shift into REVERSE at anything above a creep. This transmission shifts so smoothly that, even when trying, you have trouble detecting shift points. You need only part-throttle for downshifting below 35-40 mph, which contributes greatly to the economy and driving pleasure of the GP.