Thread: bad gas mileage and trans temps high

so i hooked up the scanner to it and heres some numbers i got, let me know if they seem off at all
speed 41mph
coolant temp 190*F
MAF 0.91
MAP 8.9
IAT 91*F
IGN Advance 15.0
ST Fueltrim11 10.9%
ST Fueltrim -0.8
LT Fueltrim -3.1
engine speed 1262rpm
abslt tps 3.5% <<<??
02s11 0.750
02s12 0.805
______________________________________

speed 19mph
load 9%
coolant temp 190*F
MAP 17.4
MAF 3.15
IAT 93*F
IGN Advance 27.5
ST Fueltrim11 -84.4%
ST Fueltrim -3.9
LT Fueltrim -21.1
engine speed 1575rpm
abslt tps 18.8% <<<??
02s11 0.805
02s12 0.805


_____________________________________________

speed 18mph
load 18.4%
coolant temp 192*F
MAP 25.1
MAF 6.40
IAT 93*F
IGN Advance 26.0
ST Fueltrim11 -68.0%
ST Fueltrim -4.7
LT Fueltrim -21.9
engine speed 2013rpm
abslt tps 25.1% <<<??
02s11 0.065
02s12 0.750

_______________________________________

speed 12mph
load 12.6%
coolant temp 196*F
MAP 20.7
MAF 4.21
IAT 93*F
IGN Advance 39.5
ST Fueltrim11 -81.3%
ST Fueltrim -12.5
LT Fueltrim -20.3
engine speed 1889rpm
abslt tps 22.4% <<<??
02s11 0.160
02s12 0.775

____________________________________

speed idle in park
load 1.6%
coolant temp 196*F
MAP 10.3
MAF 0.65
IAT 93*F
IGN Advance 19.5
ST Fueltrim11 -82.0%
ST Fueltrim 3.1
LT Fueltrim -14.8
engine speed 761rpm
abslt tps 1.2% <<<??
02s11 0.195
02s12 0.140

talked to a friend of mine that is ASE certified auto tech teacher, i showed him the same numbers i posted on here, he said my long term fuel trim shouldn't be reading past -10 and he prefers to see then below -5, seeing as mine is in some readings past -20 he finds that to be a big problem

also he noted that my MAF readings are off but he doesn't think thats related to the above issue because that would cause a lean condition, he told be at idle i should be getting around 6gps not 0.65 he also said that the other MAF numbers are off too

he commented on my coolant temps, he said they are a little bit cooler then he would like, he said it should be closer to 205* instead of 190-196*

I got about 17 city and 28ish at 60 highway if I'm lucky, usually more like 25.

yesterday i got on the highway and set the cruse at 65, then rest the mpg's went about 10 miles of it being on cruse and it said 22mpg and it was still going down

Cruise is horrible for gas milage.. It does not keep a very steady speed. But flucuates up and down within an accepted range. I get better gas milage driving myself then letting cruise take its effect.

Originally Posted by NR92

talked to a friend of mine that is ASE certified auto tech teacher, i showed him the same numbers i posted on here, he said my long term fuel trim shouldn't be reading past -10 and he prefers to see then below -5, seeing as mine is in some readings past -20 he finds that to be a big problem

also he noted that my MAF readings are off but he doesn't think thats related to the above issue because that would cause a lean condition, he told be at idle i should be getting around 6gps not 0.65 he also said that the other MAF numbers are off too

he commented on my coolant temps, he said they are a little bit cooler then he would like, he said it should be closer to 205* instead of 190-196*

Can not remember from earlier are you tuned? If not reflash you ECM not saying itll fix it but if its true that your readings are that far off its worth a shot. If your tuned sounds like you should retune it.

Originally Posted by NR92

talked to a friend of mine that is ASE certified auto tech teacher, i showed him the same numbers i posted on here, he said my long term fuel trim shouldn't be reading past -10 and he prefers to see then below -5, seeing as mine is in some readings past -20 he finds that to be a big problem

also he noted that my MAF readings are off but he doesn't think thats related to the above issue because that would cause a lean condition, he told be at idle i should be getting around 6gps not 0.65 he also said that the other MAF numbers are off too

he commented on my coolant temps, he said they are a little bit cooler then he would like, he said it should be closer to 205* instead of 190-196*

FWIW, if you are modded at all (I don't know, you didn't mention any mods) and don't have a tune, your trims will be off. You stock tune is going to be pretty close for a stock car. And I would guess that is what your ASE tech knows best. Stock cars. When you start modding, your trims are going to change. A tune will help get your trims back to where they should be. So if you are modded and don't have a custom tune, your trims will be off.

As for your coolant temps, they don't look far off to me. IMO, if your cooling system is doing its job, your engine should never run much over the t-stat temp. When it goes get up to the t-stat temp, the t-stat should open and let cooler water in, cooling down the engine below the t-stat temp. And mine does just this. I have a stock 195° t-stat. My temps will rise up to around 196-197°, the t-stat will open, and the temps will drop back down to 185-192° or so. Only if I am sitting in traffic will they ever get above 200°, and even that is only for a minute or so at a time.

the car is stock, only upgrade was a k&n cone filter

and as for the t-stat you make since completely, he commented about the fans kicking on at 215* and i am pretty sure they kick on around 195* (is this correct?) that might be why he thought it was a little cool