Curious questions

[Rawze]

(02-28-2019 )rraccerr Wrote:  2014 t680 with a ISX 15 400 Cummins. Two questions i would need help with.

1. My sweet spot on my rpm meter is at 1300 rpm. That’s where I keep my engine running over the road. But I read that an ISX should be kept at 1650-1800 to get best performance, is this true? And if so, should I forget about that sweet spot indicator?

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there is no "sweet spot". 1300 is too low rpm for pulling power (when you need a lot of boost). it is better to have it in higher rpm range - 1660 or so when pulling hard. - When not pulling hard, it is better to use the lower rpm.. it changes with loads and terrain and requirements.

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