you will loose mpg. trust me. more fuel in: mpg down

 

newpctech, your numbers are very accurate from what i have read here over the years

 

That extra fuel being added is not just getting washed down the exhaust pipes in liquid form. The point of adding more fuel is to create a more powerful explosion, and subsequently create more power.

More power means less rolling of the throttle for the same effect.

Theoretically there should be a point of "optimum" combustion where every bit of "power" is extracted from the fuel/air mix being pumped into the cylinders with no excess fuel and no excess air. Running leaner or richer than that should both negatively impact fuel economy.

The EPA specs are tuning for exhaust emissions, not optimal engine performance. Tuning leaner does not necessarily improve mileage.

 

with an o2 sensor motor running reg gas over high grade your mpg will suffer. always run the high grade and carry a bottle of octane booster to use when you can't get the good stuff. a high volume fuel stop is always a good choice, i have read papers over the years that rate fuel quality of major brands and shell has been at the top followed by chevron, phillips 66, mobile, amoco, exxon. aviod the generic cut rate places if possible

 

You may be right. I was already at stage 2 with my SE 95" kit so maybe fuel moto's stage 2 programming, while yielding some benefits, does not add noticible performance gains over the HD stage 2 download. Maybe apples and oranges here. Then again maybe I did get a bum unit. Bike still runs very well though. I'm glad I bought the PCV I guess but my bike is no faster (if that what we mean when we say performance gains) than it was before the install. I don't really notice any decline in heat although I guess with my drop in MPG by default I am running cooler internally.

 

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I mostly agree, but although you might want optimum AFR for WOT performance (12.8-13.2:1) that will not be ideal for part-throttle operation. Stock is 14.6 and some tune to 13.5-13.8 for best cooling and throttle response. It's all a compromise, so you pick your flavor. Personally, I like the effects of adding an oil cooler to control temperatures and lean the AFR's to near-stoich (14.7) for best mileage.

Leaner does improve mileage up to a point. If you lean excessively (>14.7:1) you may get detonation and a power decrease that becomes counter-productive. Stoichiometry for gas engines is reportedly 14.7:1, but although this works well for most water-cooled vehicles it causes air-cooled engines to run hot. "Stoich" may also be ideal for both in terms of gas mileage.

 

I have never worked on gas engines. But I know in the diesel class 8 trucks when the EPA got involved we leaned them out and changed timeing. We lost both power and mileage. Since they have done other things includeing spraying fuel in the exhaust if you can beleive it to reduce emissions

 

When it comes to the Gov, I can believe anything these days.

 

07 ultra added pcv (fuelmoto)intake and slipons. mymilage stayed the same.i think the biggest reason is the motor runs so much better in the lower rpms i can now use 6th gear at lower speeds without pinging and surging and i use less throttle to stay at speed. the afr is noticably ritcher i can smell it on long decels and it is cooler.