'87 GM O2 Sensor Question

[miamibob]

I replaced the original O2s at 180k miles. Didn't make a gnat's ass of difference in fuel economy. When I was doing heavy city driving and lots of short trips in mine, I saw around 12.5 mpg. And I KNOW I have no vacuum leaks.

Now THERE'S an affirmation I can live with. Don't want to be changing stuff just for practice! Changed all 4 on my '95 GM and the MPG's still suck and they were a real PIA! Only did it since I was not the original owner and the car has approx 188K.

[91waggin]

The problem with these cars is they gear them real tall for cruising fuel economy (2.73, 3.08). The problem with that is that as soon as you start doing real heavy city driving, you have to really plant your right foot to get the car moving since you need more power to get the car moving with the tall gears. If you had shorter gears, your highway mpgs might suffer some, but you'd pick up some in the city since you could use a lighter foot to get moving from every stop.