Automakers Have Lost Their Minds. 400-Plus Horsepower?

In the ‘60s automakers engaged in a horsepower war. Oddly, they’re still doing it.

In 1964, NASCAR legend Richard Petty won the Daytona 500 in a Plymouth powered by the legendary 426 Hemi V8. It produced a little over 400 horsepower in race trim. Today, it’s possible to buy a Dodge with a Hemi V8 as well. The Hellcat produces over 700 horsepower, as a production engine, and does it on pump gasoline, with a factory warranty and full emission control compliance. That’s a tremendous engineering achievement, but is there any point in producing engines that powerful for street use? The same technology that produced high levels of volumetric efficiency and low friction in today’s high-performance engines could be used to produce a smaller displacement, powerful and economical engines suited to everyday driving. But consumers insist on hundreds of horsepower for street use. Why? Jim Anderton comments. 

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Transcript of this week’s show:

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Way back in 1964, at the beginning of the NASCAR season, at the Daytona 500, a promising young driver named Richard Petty showed up with a Plymouth powered by an engine that would become legendary: the 426 Hemi.  

Chrysler’s Hemi V8, called that because of the hemispherical shape of the combustion chambers, ran away with that race and became so dominant that NASCAR actually banned the engine for a time in 1965. The word Hemi became synonymous with horsepower, and Stellantis still uses it today when marketing high-performance engines.  

The carefully race-prepared, custom-made Hemi in Richard Petty’s race winning car in 1964 produced slightly more than 400 horsepower. It made that power with no regard whatsoever to engine wear, fuel consumption or, of course, emissions. You could buy a limited number of hemi-powered street cars as well, but they produced far less horsepower.  

Fast forward to today: you can buy a hemi-powered Dodge today, just as you could in 1964. Of course, today engines are hobbled by strict pollution controls and must be durable enough to withstand the long powertrain warranties commonly offered by manufacturers. And today’s engines need to generate reasonable fuel efficiency to avoid U.S. government penalties. It is reasonable to expect that with all these constraints, today’s engines would be somewhat less powerful than the originals. Except horsepower has gone the other way.  

A modern Charger Hellcat generates over 700 horsepower, in street, unmodified trim. That’s with full emission controls, good engine durability and reasonable economy. In rough terms, engine power has essentially doubled over the last half-century for the same displacement. Why?  

It’s been a combination of alterable factors, but critical ones are multiport fuel injection, computer feedback control of fuel mixtures, variable valve timing and the development of new materials for castings, bearings and valves. For smaller engines, it’s been about forced induction, mainly through turbocharging, but with a significant number of factory superchargers as well.  

It took 400 horsepower to win Daytona in 1964, but that figure is commonly seen under the hoods of SUVs driving the kids to school on Monday morning. And it is not only incredible that this kind of power output is now common, but that it’s actually mass producible. It’s hard enough to mass-produce automobile engines that withstand EPA durability requirements for emission controls and can survive long enough to avoid warranty claims in an industry where powertrain warranties sometimes reach as far as five or six years.  

But to do so with the significant increase in horsepower is, frankly, remarkable. 

I once raced a 1976 Chevy Camaro with a five litre V8. It produced something in the order of 165 horsepower. I drove to this studio today in a four-cylinder Honda that produced the same horsepower, normally aspirated. And despite higher operating temperatures and much higher typical engine RPMs, the Honda engine has lasted twice as long as a typical street driven cast-iron V8 of the mid-Seventies.  

Oddly, however, what hasn’t happened is the use of all this high horsepower technology to allow much smaller engines to propel larger, heavier vehicles. I used to tow that ‘76 Camaro with a 1985 Ford F 150, which was powered by a five litre straight six engine with a single barrel carburetor. It produced 122 horsepower, with 255 foot-pounds of torque.  

That’s significantly less horsepower than my wife’s Mini Cooper, but it hauled and towed just fine. It went between 10 and 15 miles for every gallon of gasoline doing it, so you would think that modern pickups would use something like one point five litre or two litre four-cylinder engines combined with 10-speed transmissions to deliver the same performance with much better fuel efficiency.  

But that’s not what’s happened. Instead, we have a horsepower war in street vehicles as well. A 2022 F-150 uses a base 2.7 litre turbocharged V-6 that generates 325 horsepower with 400 foot-pounds of torque. Fuel mileage is between 20 and 25 miles per gallon.  

More power, better economy. But I have to wonder, how economical could the unit be if it was designed to deliver horsepower and torque figures similar to my ‘85 F-150? 35 miles per gallon, maybe more? We’ll never know, because electric vehicles will soon take over the market, and will be measuring efficiency much differently then. But in the half-century of development that I just described, consumers have opted to choose horsepower over fuel efficiency in almost every automotive product. For street use, I have to wonder why. 

Written by

James Anderton

Jim Anderton is the Director of Content for ENGINEERING.com. Mr. Anderton was formerly editor of Canadian Metalworking Magazine and has contributed to a wide range of print and on-line publications, including Design Engineering, Canadian Plastics, Service Station and Garage Management, Autovision, and the National Post. He also brings prior industry experience in quality and part design for a Tier One automotive supplier.