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Discussion Starter · #1 ·
I've noticed that the TH runs pig rich at cruising speeds. AFR is around 13.4 and thus is causing poor gas mileage; 16-17 mpg cruising.

My question is, how much better on cruising load gas mileage have you guys seen when optimizing the stock tune, or even full blown upgraded tunes on 93 pump to be in the 14.7-15.0 AFR range?

Any reason why Chrysler set the AFR so pig rich at cruising loads?
 

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I've noticed that the TH runs pig rich at cruising speeds. AFR is around 13.4 and thus is causing poor gas mileage; 16-17 mpg cruising.



My question is, how much better on cruising load gas mileage have you guys seen when optimizing the stock tune, or even full blown upgraded tunes on 93 pump to be in the 14.7-15.0 AFR range?



Any reason why Chrysler set the AFR so pig rich at cruising loads?


It’s really not rich, as what you are seeing in the AFR is based on a stoich of 13.85, not the 14.7 you are probably used to seeing.

It’s why most tuners tune and talk in terms of lambda, as it gets confusing


13.4 on stoic 13.85 is about 14.2 on a 14.7 stoich scale, for reference

Sent from my iPhone using Tapatalk
 

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Discussion Starter · #3 ·
It’s really not rich, as what you are seeing in the AFR is based on a stoich of 13.85, not the 14.7 you are probably used to seeing.

It’s why most tuners tune and talk in terms of lambda, as it gets confusing


13.4 on stoic 13.85 is about 14.2 on a 14.7 stoich scale, for reference

Sent from my iPhone using Tapatalk

Oh wow, I had no idea. Good to know.


Thanks man.
 
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