Emissions and fuel economy regulations are a good thing. Just think about that. I know, that emissions meant some very low horsepower numbers in the 1970’s, and caused more than a few muscle car engines to die off, but look at where we are at now. We wouldn’t have the awesome new engines that we do now without the fuel economy and emissions regulations that the cars have to meet.
When you think about it, all the muscle car engines of the classic muscle car era were designed in the 50’s or the early 60’s. There were many parts of the design of them, that had some serious limitations, either due to the manufacturing abilities of the time, or the understanding of how engines made power. There is a reason that there are only two engines left being made that are still considered part of an engine family from the muscle car era. Those two are the Viper V10 and the 4.3 V6 that GM uses in its pickup trucks. And both of those have very little in common with their Chrysler LA and small block Chevrolet ancestors.
For the modern V8’s (which sell in much higher numbers I am sure, especially the Viper V10) they are newer designs that share little to nothing with the older V8s of the 50’s and 60’s. The heads flow much better, so they don’t need such a radical cam shaft to make power. The engineers discovered that cylinder head combustion chamber designs that worked for emissions and fuel economy, also made more power due to a more complete and efficient burning of the fuel.
That lead to the manufacturers to rethink the way that the ports were laid out, and many other improvements that lead to the horsepower that we have available now.
Don’t believe me, lets look at the Ford 302/5.0 engines. The highest power rating in the 302 in the 1960’s was in 1968 with a Shelby specific high output version that made 315 horsepower and 333 lb-ft of torque. Those numbers are gross, versus the more conservative net horsepower measured today.
Lets compare that to the new DOHC 5.0 in the Mustang. Since we went with the highest power rating in the 302 I could find, lets look at the Boss 302 version of the new 5.0. That was rated at 444 HP and 380 lb-ft of torque. While the displacements of the two are not identical, they are only like 9CC different in displacement, so close enough for this comparison.
And if we look at fuel economy, there is no comparison. That is easy to say, since there was no fuel economy ratings in the 1960’s. But if we look at the Boss 302, it is rated at 17 MPG city, and 26 highway with a manual transmission. I would be really surprised if a high performance 302 from the 60’s could even manage 17 MPG on the highway.
Combine that with the drivability and reliability of modern engines, imagine a 444 carbureted 302 versus the modern Boss 302 and it is hard to compare the two. And it is all because of having to meet fuel economy and emissions targets.
The only thing missing is the lumpy idle of the old V8s. But the RPM variations can cause problems with all the computers. But given all the other pluses, it is a small drawback.
Unfortunately, the ever increasing fuel economy regulations, along with increasing crash standards are making it more and more difficult to get a V8 to meet the needed MPG. Power keeps going up, but unfortunately so does the weight with the ever increasing levels of equipment that cars are coming with.
Lighter weight would help with the fuel economy issues, but the weight keeps increasing on cars. It is due to more and more equipment on them, after all, when was the last time you saw a car without power windows or locks? That and the higher crash standards also mean more weight. I am ok with the crash standards, since cars today are a lot safer than they used to be. After all I would much rather be in a crash in any new vehicle, than something from the 60’s. But where is the tipping point, where we reach the point of diminishing returns? I think we have probably already reached that.
But that is another discussion than this one. And I still stand by the fact that having to make an engine that meets fuel economy and emissions regulations is why we have the horsepower we are enjoying now.