# 150 miles until reduced engine speed



## Barry Allen (Apr 18, 2018)

B162009 said:


> nothing serious enough to put excessive strain in the car and it was like it redlined but at 4K?


The power peak is at about 3,750 rpm and it falls off fast after that - like a hockey stick chart where power just falls to nothing after 4,000 rpm. I know this is probably for emissions, because at high engine speeds there isn't enough time for thorough and complete combustion of injected fuel, so this would mean a lot of soot in the exhaust going into the DPF - it would load up quickly.

You can totally beat the heck out of the engine to a certain extent and you won't harm it. The boost floor is about 1,500 rpm at sea level - that's where reasonable amounts of torque start to build. Once you hit about 1,900 rpm at sea level the engine pulls hard because that's about where it starts to generate 100% of available torque, and keeps the torque level through about 4,000 rpm. You gain no performance by going past 4,000 rpm so if you shift to keep engine speed between 2,000 and 4,000 rpm you can wring all the speed you want out of the engine and it won't hurt anything.


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## Barry Allen (Apr 18, 2018)

B162009 said:


> opinions? Without spending 140 on a diagnosis


Do nothing and see if the light goes away after a few drive cycles. It's probably a hiccup of something and it will just go away if you ignore it.


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