There was a time when a car was judged by how much you had under the hood – literally.  For many V8-powered car drivers, the size of their motor, in cubic inches, was like a badge of honor – a badge frequently worn on the front quarter panels so that all the world could see the exact details of the engine installed in the car.

Starting in the mid-1960’s with the Pontiac GTO, muscle car makers slugged it out on the boulevards and highways all over America, determined to produce if not the fastest car, then at least the one with the biggest engine so that owner bragging rights could be maintained.  Even luxury car makers Cadillac and Lincoln got in on the action, with engines topping 500 cubic inches finding their way under the hoods of luxury barges and executive coupes. Cadillac had a 472 in 68-73, and a 500 in 70-76.  The 500 made 400 hp in the first year, and then was down to 190 by the end of production – a sad decline.  Lincoln ran a 462 in the Continentals from 66-68.  I had two Continentals with this motor.

The HP Wars

The roots of the horsepower war went back to the participation of the Big Three (Chrysler, General Motors and Ford) in motorsports, in particular NASCAR and NHRA drag racing.  Since a number of teams had full factory support in that era, automakers were able to test out their designs in the high-stress environment of a race and then make the appropriate changes for street use.  Of course, there were always a few engineers and designers who were curious about what would happen if they made these high performance racing engines directly available to the public, and some of these track-ready mills found their way to customers through obscure choices on options sheets before management wised up and shut down this creative form of horsepower distribution.

When General Motors decided it was time rehabilitate their image and withdraw from motorsports participation, there were those within the company who were concerned that Chevrolet and Pontiac in particular would fall behind in terms of engine development.  This led to the idea of taking a 325 horsepower, large displacement V8 – measuring 389 cubic inches – and stuffing it into a mid-size car, the same platform that was used for the Pontiac LeMans.  A loophole in GM internal regulations made this possible by branding the GTO an ‘options package’ and not an actual vehicle itself, and a legend – not to mention the very first muscle car - was born.

Other car makers were quick to notice the popularity of this factory hot rod and began to step up programs of their own to shoehorn larger and larger engines under the hoods of their smaller cars.  Chevrolet had been selling the big block 409 in their full-size sedans but eventually upgraded to the 427, which produced up to 435 horsepower and was installed in the Impala as well as the Biscayne sedans.  For their mid-size cars, in the mid to late 1960’s a 396 cubic inch engine would find its way into the Nova, Camaro and Chevelle.  Chrysler fought back with the 383 and the 440, rated at 325 and 375 horsepower respectively, while Ford introduced their FE series of engines, installing a 390 cubic inch V8 in the Mustang and eventually upgrading both the Mustang and the Torino to the 428 Super Cobra Jet.

1970 – The Peak of Power

By the dawn of the 1970’s, it seemed as though the cubic inch wars had reached their golden age.  Companies had even taken to advertising the size of the engine anywhere they could on the exterior of the vehicle – the rear quarter panels, the front fender, even on the hood or hood scoop.  Chevrolet had stuffed a 365 horsepower, 454 cubic inch engine into the Chevelle, while Pontiac countered with a similar 455 unit in the Firebird.  Ford punched the Cobra Jet out to 429 cubic inches to produce a fire-breathing 375 horsepower.  However, it was Chrysler who really upped the ante by offering the 426 cubic inch Hemi V8 across almost their entire product line.  Conservatively rated at 425 horsepower, this engine used hemispherical combustion heads to increase engine performance.  The motor could be had in some of the most famous muscle car names of the day – the Charger, the ‘Cuda, the Challenger and the GTX.

The writing was on the wall

While it might have seemed like the sky-high horsepower party had just gotten started, there were those who had other ideas.  The Environmental Protection Agency was instrumental in passing an extension of the Clean Air Act in 1970 that saw not only the introduction of unleaded gasoline, which made it harder to maintain the necessary high performance engine compression ratios, but also the mandatory use of power-robbing pollution controls in engines that were designed to reduce smog and other vehicle emissions.  On top of this, the OPEC oil embargo raised gasoline prices to the point where it became difficult for some owners to justify their large engine’s equally large thirst for fuel – not to mention the fact that insurance companies had finally caught on to the fact that muscle car horsepower was perhaps significantly higher than had been initially reported by automakers.

A truce is declared (but for how long?)

These factors combined to slowly extinguish the flame that had driven the cubic inch wars for close to a decade.  By the end of 1972, while it was still possible to purchase a large displacement motor in an American car, the power it produced was but a shadow of its former self, and the rest of the decade saw horsepower numbers dwindle to a fraction of their former glory.

The wars today

It is tempting to compare the current era of horsepower wars with the CID battles that occurred during the heyday of muscle cars.  Certainly, when looking around at offerings from not only domestic automakers but also German luxury builders, it seems as though a renaissance of power has been building over the last five years.  In the space of less than a decade, passenger cars have gone from a 300 horsepower peak to almost double that.  It is possible to walk into a modern showroom and drive out in a Mustang, Challenger, Charger or Corvette with horsepower numbers edging 400 and some cases 0topping 500.  Likewise, BMW Motorsport and the Mercedes AMG division have sedans and coupes which boast over 600 horsepower and in the case of Mercedes, 738 lb-ft of torque.  Shocking numbers to be sure, and this does not even include super cars like the Viper or the Corvette ZR1, another area where car companies seem to be pulling out all of the stops to top each other with every increasing horsepower figures.

There are some important differences between the power leaders of today and their muscle car ancestors.  The first is technology.  While car companies in the 60’s and 70’s were focused on stuffing large engines into small vehicles, modern engineers are making use of technological innovations to squeeze every last drop of performance out of engines that may occasionally crack the 400 cubic inch barrier but which are a far cry from the big block engines which dominated their spiritual predecessors.  Variable-valve timing, variable length intake runners and incredibly advanced engine management systems and fuel delivery have all made it much easier to design powerful, smaller displacement motors.  Forced induction in the form of turbochargers and superchargers also provide shortcuts to exceptional power from standard-sized engines, and most of these advances have translated into radically improved fuel economy over standard big block engines of yesteryear.

Another significant change can be seen in the way that horsepower is reported by auto manufacturers.  Back in the 1960’s, horsepower was measured by taking the engine and running it on a stand – completely outside the car and without any accessories like power steering or the alternator causing parasitic drag.  Many of the engines that were tested were also special, hand-built versions which had been constructed to very fine tolerances, giving them an edge over assembly-line cars when it came to muscle.  Naturally, some of the horsepower numbers that came out of these tests were optimistic, in the sense that street cars weren’t quite up to the same build standards and had to deal with running the basic systems that a car required in addition to providing enough torque to smoke the rear tires.  Car companies were also notorious for flubbing power numbers in order to help with advertising, making it difficult to track down exact figures for specific motors.

In today’s vehicles, horsepower is determined by a much stricter process that involves measuring the power at the engine’s flywheel with the engine installed in the car.  This means that all power-robbing accessories are present and accounted for, making it much harder for an automaker to be imprecise when flaunting their vehicles power.  This also means that the engine numbers of today, while much higher than those of the past are also much more accurate, giving modern automobiles a definite edge when it comes to performance.

The question, of course, is where does it all end?  If the current pace of automotive progress continues unabated, it is not a stretch to say that in a few years time we could all be driving vehicles which average 500 horsepower, with 1000 horsepower sports cars representing the cutting edge.  Of course, reality has to come into play at some point, and for most of us it already has. 

Is this the beginning of another end to the wars?

While technology may have made high horsepower engines more efficient, rising fuel prices have worked against these vehicles so that they are still much more expensive to drive on a daily basis than a smaller engine with fewer cylinders.  Given that the price of gasoline shows no signs of dropping back to inexpensive levels drivers enjoyed at the end of the 1990’s, car companies such as General Motors have already started to re-think some of their V8 powered sedans and coupes.  In combination with the pressures car companies are facing over greenhouse gas emissions, it seems as though similar factors to those which crunched the first horsepower boom are starting to zero in on the second.

This second golden age of powerful automobiles is something that should be enjoyed for as long as it lasts.  It could be the last hurrah for fossil fuels, as it seems like the rumble of a V8 engine is in danger of becoming just another automotive memory, like wooden wheels and the Studebaker.  Until we get to that point, however, there is plenty of horsepower begging to be unleashed on the nation’s unsuspecting roadways.

By Benjamin Hunting

Benjamin is a professional, published writer living in Montreal, Canada. He has a deep background in three industries: medical, music and automotive. 

He is President of an independent record label for close to a decade, and also spent over eight years as a musical promoter and touring musician.

He has restored and raced automobiles for 15 years, and writes for a number of automotive publications on the web.