Highest SAFE cruising AFR's

[LEMHEAD16]

I am going to be traveling from Tulsa to Boise soon and want to maximise my MPG. What is the highest AFR I would want to see when crusing at like -10 mmhg. Could I push it to 16.5 - 17 or would EGT's get high?

[virus77]

I wouldnt do higher than 17 but you can probably get away with 16-16.5 pretty easy.

[1WheelWonder]

I agree with Virus.

[LEMHEAD16]

thank you

[TXCumtrensh]

god that lean

[hannibal]

^ for cruising, apparently is not that lean.

You wouldnt want to tune for 16:1 for WOT...

[skatanic28]

i was getting misfires at ~15.5+ during cruise.

the stock ecu kept it around 14.7-14.9, so thats where i set my targets.

[Florida240sx]

I would keep it at 14.7 to be safe.Just because it's onyl a coupel dollars extra $$ to keep your motor safe.Besides running it lean will make it run hotter and prts out faster will it not???yes it should be safe but you'd cut down on longevity would you not??

[Structure240sx]

that car can cruise jsut fine even at 17:1 afr

once it starts hitting 18-20 is when it can hesitate/missfire/buck

[Jookmasta]

ya just make sure u dont go into boost at all............i personally think that u shouldnt tune for it. i can never seem to not go into boost when im on a roadtrip.............even though i have cruise control......

[Edub1]

Durring cruising your ECU should be in closed loop in which case it's going to adjust based on sensor feedback. Why monkey with the closed loop operation?

If you have a piggy back, this can create problems - so I'm told.

[Structure240sx]

as soon as you put load on the motor and get into boost the afr's will come down to where they should be

[KATwo40]

Yub, like structure said, they'll come back down. If you're running safc you might want to lower your high throttle point just to be safe.