While I was still in university studying Engineering, we did some simple practical tests on an old Otto cycle engine. This engine does not have any of the modern advancement in current cars such as VVT etc, it was just a simple basic Otto cycle engine.
We monitored its max power output point and max efficiency point. I understand that the numbers we found from that experiment will not relate directly to modern cars but I was curious if you could use some of the conclusions.
Note, this is an engine only experiment, so to translate into normal driving, it is pretty easy to see that you use the respective gear ratio to keep your engine at the efficient RPM (later in the post).
Max power output we found to be at around 6,000 rpm (give or take a few hundred either direction, its been a while so I don't recall the exact figure). Maximum efficiency however came at around 3k rpm.
The reason I bring this up is because I have seen a few places mention that it is better to lower RPM as the engine consumes more fuel but I would argue that if the engine is not at its peak efficient point, you may as well rev it up more to gain a better speed/fuel consump ratio.
So I guess I'm just wondering if optimum engine efficiency, and thus, fuel efficiency while driving is achieved at around 3k rpm?
We monitored its max power output point and max efficiency point. I understand that the numbers we found from that experiment will not relate directly to modern cars but I was curious if you could use some of the conclusions.
Note, this is an engine only experiment, so to translate into normal driving, it is pretty easy to see that you use the respective gear ratio to keep your engine at the efficient RPM (later in the post).
Max power output we found to be at around 6,000 rpm (give or take a few hundred either direction, its been a while so I don't recall the exact figure). Maximum efficiency however came at around 3k rpm.
The reason I bring this up is because I have seen a few places mention that it is better to lower RPM as the engine consumes more fuel but I would argue that if the engine is not at its peak efficient point, you may as well rev it up more to gain a better speed/fuel consump ratio.
So I guess I'm just wondering if optimum engine efficiency, and thus, fuel efficiency while driving is achieved at around 3k rpm?