Gas/O2 Sensor Problem ?!?!

[1995PGA]

I am now driving 5 days a week on a 400 high way (100km/h)
i drive about 1 hour aday on it...and i would think that i would have better gas milage because i dont stop. But i am only getting the same milage?....does this mean i should get a new O2 sensor..or does this i mean it is really good ?

i am getting around 550-600km per tank

i am driving a 1995 Grand Am SE V6 3100SFI
i have a brand new air filter, oil is changed, i just put injector cleaner when the tank was full.

p.s. Also what is everyone else getting per tank with this engine?

[doobiess]

Well dude i have a 94 grand am 3100 sfi auto ... and for me i have a prob.... im only get at best 420km's per tank and that has to be on the highway... im getting about 300 km's per tanks.. and here its 93.9 gas so i put in about 45$ a week.,.. trust me your good ... I wanna know why im so bad...

But as for it.. replacing the o2 sensor.. isnt cheap and cant guarantee anything because i replaced mine and i dont know if it did anything but personallly i would say check the basics.. air filter... clean oil spark plugs.. but other than that your extremly lucky to have that sort of mileage...

and also as for me to get 420 i was doing 130 kph... and if i hold 80km's i get 400 kms...

[rixGAphx]

Nobody can relate miles per tank or kms per tank, because we fill-up and draw-down to different levels.
A 'tank' for me might be 10 gals/35 l, for you it might be 13 gals/47 l.

The proper way to measure is actual distance to actual volume.

With proper tire inflation, speeds of about 60mph/100kph, and little cargo, your vehicle *should* get about 22 mpg.

22 miles = ~ 35 km
1 gal = ~ 3.6 l
Therefore, 22 mpg = ~35km / 3.6l = 9.6km/l = 10.4 l/100km
In Europe, fuel consumption is commonly referenced as the number of liters of gasoline consumed to drive 100 km; in this case 10. liters.

A bad O2 sensor will:
1. Cause the PCM (engine 'puter) to think something is wrong; the PCM will set itself on 'default, which is a very gas-guzzling rich condition (about 15 mpg instead of 22); AND,
2. Set off an engine code and the SES/Check Engine light.

A slightly bad O2 sensor will erroneously read that the exhaust is lean, and enrichen the mixture SLIGHTLY.
There's only a slight tolerance here, maybe 5%.
That works out to about 1 mpg between a car running properly and one running with an O2 sensor just about to fail completely.

So, if you're getting significantly bad milage (and we don't know what your milage is yet), it prolly canNOT be attributable to a bad O2 sensor.

A plugged, or partially plugged, cat would be a strong candidate for poor milage.

Get back to us.
-Rick

[1995PGA]

yea i do 120-130km
cruise control on (that might be my problem)
but its odd how i get the same as in the city, where it is stop, go,stop, go?!?!
i have it all.....new tires 34 lbs, new air filter, new oil, everything
here i had a chance to get 60.7 and i drove past it jsut as i saw it, and 1 block down it was 79.7. grr...
i should have stopped!

...
i also live on the gravel road (1 mile)
i hear that wastes gas :???:

$45 per tank???
i think mine takes 42 if the gas is at 0.80

i try to accelerate normally...may help?

[1995PGA]

tires: Michelin Harmony 34lbs
speed 100-130km/h
i drive 100 km per day on the 400 series (100km/h)

im alittle lost on your equation ?!?!
my tank is 57.5l
i use regular gas

no cargo except me (110lbs) and 50 lbs of school books

[goldenboy]

Originally posted by 1995PGA
I am now driving 5 days a week on a 400 high way (100km/h)
i drive about 1 hour aday on it...and i would think that i would have better gas milage because i dont stop. But i am only getting the same milage?....does this mean i should get a new O2 sensor..or does this i mean it is really good ?

i am getting around 550-600km per tank

i am driving a 1995 Grand Am SE V6 3100SFI
i have a brand new air filter, oil is changed, i just put injector cleaner when the tank was full.

p.s. Also what is everyone else getting per tank with this engine? I have a 96 GT 3100 and i make 450-500km city/highway combined and when i do only highway and i wait that the tank gets really empty i can do 600km+ just like u,so u dont have a problem trust me thats pretty good for that size of car.

P.S. on the highway i always put my cruise between 110-120km

[1995PGA]

what do you mean that size of car?

1755kg isnt that light for a car?

[goldenboy]

Originally posted by 1995PGA
what do you mean that size of car?

1755kg isnt that light for a car? Thats what i mean for a car that weights that much it does pretty good mileage

[Colin]

Want better mileage ? Slow down . You'll use less gas at 100 kph than at 130 kph . :D

[1995PGA]

but...isnt it better fuel economy when you drive 10 km/h or more compared to the speed limit?

[rixGAphx]

Originally posted by 1995PGA
but...isnt it better fuel economy when you drive 10 km/h or more compared to the speed limit?
NO!!!

Best highway fuel economy for gasoline sedans/coupes in the 3000-4000 lb range (1365 - 1820 kg) range is achieved at *about* 45 mph (72 kph).
Less than that and the engine, with *normal* gearing is turning too slow for optimum efficiency.
More than that and the wind resistance starts to really suck the horsepower.

If you are ever on the highway halfway passed nowhere with very little gas, accelerate smoothly up to 45 and set the cruise control.
That's your best opportunity to reach civilization.

-Rick