Big gas mileage difference btw city and highway

The EPA's fuel economy for 2001 Impala base is 20/30MPG. My one can get over

30 when cruising on highways. But in city driving, it has been below 17 since I acquired it a year ago. The car runs basically ok, just recently developed a kind of scraping noise upon acceleration, and I feel some loss of acceleration power. The dealer checked it, but found no problem and told me the noise could be "normal".

I just have been wondering what can cause such a significant difference between city and highway driving?

Thanks.

Reply to
Simon
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City driving milage depends very much on driving style, much more so than highway driving. Is the car automatic tran? Do you left-foot-brake, and rest your foot on brake? Even if you don't, do you use brakes heavily, or do you play lights? If it is a stick, do you shift early or late?

Reply to
Don Stauffer

Depends on the speed at which you are crusing, whether you accelerate to pass a lot, drive in flat or hilly country, etc. If you are using a built-in milage computer remember that they are not consistent and that the readings shown when the tank is full to 3/4 will probably be different from when the tank is 1/4 or lower.

But in city driving, it has been below 17

Driving "style" - are you first across the intersection? And location

- do you drive in very heavy urban traffic (NYC) or in the Kansas City

10 minute rush hour. Are you driving with the AC on in very hot summer months - expect the intown milage and acceleration to be down some.

No way to diagnose scraping sounds over a forum - sorry.

Reply to
John S.

Thanks all. Sure the car is auto tran. And I'm in a small city on Canadian flat prairie, on the way to work, only a few stop signs & red lights, minimum waiting at "rush hour". I'm a caring driver, try to avoid unnecessary braking, sharp acceleration, and seldom use AC in town. But conversely I use AC on highways a lot.

A couple of other things with the car I may better mention:

- After a stop at stop sign or red light, the car won't move when I release the brake, have to press the gas to get it going. The dealer says it's now normal for many kinds of GM cars.

- It has huge momentum once speed is gained. Have to brake hard or take long distance to slow it down. I think all large size cars (this one V6,3400) do the same.

I wonder if any settings with the car could contribute to the difference in the gas mileage?

Reply to
Simon

My '93 Eldo gets 15 local, 28 highway. Heavy car. It is what it is. FWIW

Reply to
MisterSkippy

I had the same experience with a 2003 Malibu LS 3.1 V6. It was EPA rated

20/29, but I averaged 17/31. I replaced the Malibu with a 2004 Chrysler Sebring 2.7 V6. That car is EPA rated 20/28. I average 22/31. Both cars were used for the same commute over the same times of the year. Before the Malibu, I drove a 1997 Grand Caravan 3.3 V6 that was EPA rated 18/24. I would average 20/26. So, I *always* do better than EPA mileage, have for years. The ONLY *exception* was the Malibu where I couldn't come close to achieving the city EPA mileage rating, but exceeded the highway rating.

I've read articles where people have complained about GM's city mileage being so far below ratings (or below other manufacturers cars). Vehicle "system load" will have a larger percentage influence on a idling engine compared to a "working" engine. Perhaps there is something to that angle.

Reply to
James C. Reeves

Keep in mind that the Impala is not an extremely heavy car, if it takes a long time to stop you probably need brake service.

I don't think its normal for your car not to creep. I've driven an '02 Impala, '00 Grand Prix, and some GM SUV's and all of them creep. You might want to get a second opinion on that.

Reply to
Masospaghetti

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