Terrible Gas Mileage...suggestions?
02-21-2009, 10:08 AM
#21
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Lousy O2 sensor performance from the long tubes is one
good possibility. That can jack your mixture-point a lot,
worse in cold weather and at low gas flows. The lost
efficiency from the big cam is another, I took a few MPG
hit when mine went in.
You can bump the highway-cruise mixture around some by
detail changes in the tune (esp. the O2 sensor switchpoint
and perhaps the proportional fueling). The faster, tighter and
leaner you make the feedback, the less time you'll spend off
in the mixture-weeds making stank instead of efficient power.
good possibility. That can jack your mixture-point a lot,
worse in cold weather and at low gas flows. The lost
efficiency from the big cam is another, I took a few MPG
hit when mine went in.
You can bump the highway-cruise mixture around some by
detail changes in the tune (esp. the O2 sensor switchpoint
and perhaps the proportional fueling). The faster, tighter and
leaner you make the feedback, the less time you'll spend off
in the mixture-weeds making stank instead of efficient power.
02-22-2009, 11:03 AM
#22
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let's say it's not the tune, then what could it be? it's not like there's a **** to adjust something on the stall or the cam. would you pay parts & labor to swap in another cam or stall? or would you, first, get the tune checked out by a better shop for $200-400?
02-23-2009, 11:01 AM
#23
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You might check for vacuum leaks, such as the little
rubber "PCV neck" piece which is prone to crack or
chafe open, intake seating leaks and so on. This is
a good way to get excess idle air and waste fuel
pushing against the brake.
rubber "PCV neck" piece which is prone to crack or
chafe open, intake seating leaks and so on. This is
a good way to get excess idle air and waste fuel
pushing against the brake.
02-23-2009, 11:16 AM
#24
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https://ls1tech.com/forums/general-m...-your-car.html
02-23-2009, 11:28 AM
#25
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I am getting 15mpg with mods installed in sig (untuned).... hope to get the same or beter mpg after cam install and tune..... if not im fine with it, the car will be bad ***!
02-27-2009, 07:04 PM
#27
Ready for injector cleaning? Hehe pick up some seafoam.
https://ls1tech.com/forums/general-m...-your-car.html
https://ls1tech.com/forums/general-m...-your-car.html
02-28-2009, 11:45 PM
#28
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most i ever got was 372 but that was like 5 miles to the freeway from the city then the other 367 on the freeway with no traffic and doing 65 with cruise control on. normally i get anywhere from 200 to 240 depending on my driving habit those days.
03-02-2009, 09:52 AM
#29
Sounds like the OP needs to start with a full tune-up and also Seafoam the car, then recheck the mileage. If it's still shitty, you may have to look into other possible issues, such as the tune.
I may have an M6, but I've got a mild H/C setup with 4.10s and a short geared transmission and I still get low to mid 20s highway and mid teens around town.
I may have an M6, but I've got a mild H/C setup with 4.10s and a short geared transmission and I still get low to mid 20s highway and mid teens around town.
