It has always been my understanding that the vehicle HP ratings provided by automotive MFGs and the peak HP ratings obtained by dyno testing are instantaneous maximum output figures and the engine of the vehicle should not be relied upon to provide that level of power continuously. Similarly it has been my understanding that industrial engines such as those found on pumps, generators, tractors, etc. are rated on continuous power output. For example a sports car rated 500hp can indeed deliver 500hp for a few seconds on the drag strip, but if you were to hitch a loaded 18-wheeler trailer to it and expect it to deliver 500hp for a long period of time, the engine would burn up. Conversely a 500hp rated 18wheeler would not have this problem (exclude gearing and such; focus is on power output). And I feel this is evident in the design of the 500hp 18wheeler engine (huge thermal mass & giant radiator) vs the 500hp sports car engine (light weight, small radiator).
I tried to find a rule of thumb for determining the reasonable expectation of continuous HP of an automotive engine based on the peak HP rating of the MFG. In doing so, I was surprised to find absolutely nothing, and further, I cannot even find any hint of confirmation of my original assumptions. Am I wrong? If a sports car is rated 500hp can we expect it to deliver 500hp continuously if used in a different application than getting through a quarter mile in under 12s? If I used that engine in an agricultural application pumping massive volumes of water for weeks on end, would there be a problem? If not, then why are the agricultural pumps in use, using massive diesel engines which weight 3x-4x as much?
I tried to find a rule of thumb for determining the reasonable expectation of continuous HP of an automotive engine based on the peak HP rating of the MFG. In doing so, I was surprised to find absolutely nothing, and further, I cannot even find any hint of confirmation of my original assumptions. Am I wrong? If a sports car is rated 500hp can we expect it to deliver 500hp continuously if used in a different application than getting through a quarter mile in under 12s? If I used that engine in an agricultural application pumping massive volumes of water for weeks on end, would there be a problem? If not, then why are the agricultural pumps in use, using massive diesel engines which weight 3x-4x as much?