dramatic city vs freeway mileage difference.. tranny?

[91Beater]

To the tune of 16mpg city / 28mpg freeway.

On the freeway cruising along, the automatic tranny isn't really doing anything as the TC is locked and stays in top gear.

I get 15-16mpg with a lot of city driving. 18mpg with everyday 70hwy/30city driving.

I was surprised I got 28 mpg going from Van, WA to SEA, WA.

[SILINC3R]

you use more fuel due to stopping and starting where as highway cruising you dont.

[kimokalihi]

Sounds normal to me except maybe a little low but I don't know how serious of city driving you're doing.

[cj91legss]

I get 18mpg city/freeway driving

[evolutionmovement]

Maybe acceleration enrichment is too much. How old's the O2 sensor?

[91Beater]

The O2 sensor is probably 1991 original with 200,000 miles on it.

Mostly intercity suburbia driving which is a mix of freeway and signaled highways. The city driving is only the last mile or so. That nets me 17-18mpg.

28 mpg hot is the best I've done. That is, filled up with the car hot in Vancouver. Drove 170 miles north on I-5 in fairly light traffic and immediately filled after exit. Cruise control at 65-75 the whole way. This is on Pacific NW 10% alcohol fail blend.

[evolutionmovement]

I always drive mostly highway, so I don't know if that's normal and mine wasn't a turbo. I averaged 25 driving aggressively. Even the Focus gets hit by a city-highway mix since I can go from a 37 average almost all highway over a tank to as bad as 31 if I hit mostly really bad highway traffic and city driving. Maybe that's normal for these, then.

[Apex3]

Turbo or L?

In my turbo I always got 25.5 highway going Pullman to Seattle and back. I get 17-18 city for mostly suburbs.

[91Beater]

FWD 4EAT NA.

[Apex3]

Yea that sounds awful for city driving in that case, but I don't know what to tell you about why

[evolutionmovement]

I'd replace the o2.

[Legacy777]

I'd say low 20's is probably going to be the most you'll get driving with mostly city driving. So it can't hurt to replace the O2 sensor, but I wouldn't expect a huge jump in mileage while driving in the city.

You can also try and reset the ECU, pull the battery cable or fuse 14 for about an hour. This will reset the long term fuel trims, which may help temporarily.

Also, how would you describe your driving style?