Gas mileage issues

[ammcf1]

Any help on this one?

I have a 1994 Metro, just over 100,000 miles. The mileage is coming in right around 28 to 32 MPG. I feel like it should be much better than this (I used to have 1989 that got 44 MPG consistently). Am I right? If so, what are the first things I should look for to improve the mileage?

Thanks

[Mike_Van]

Please post engine type (3 or 4 cyl) and transmission.

The best case for mileage in a '94 would be a 3-cyl (1.0 litre) with a manual trans. That combo should do better than what you posted (45-50 highway MPG expected).

Can you check the timing to see if it is off?
Have you checked for air intake restrictions?
Spark plugs & wires OK?
Fuel filter clogged?
Any idea if the brakes could be dragging?
Plugged Catalytic converter?
Are there any codes stored ? (check engine light on)

[ammcf1]

Sorry, its a 3 cyl - automatic transmission

No check engine light
No dragging brakes

How do I go about checking air intake restrictions?
How do I go about checking the timing?
How do I check the cataliytic converter for plugging?

My first thought was the fuel filter, so I guess I'll begin there. I also know how to do the plugs and wires, so I can do that.

Thanks,

[Woodie83]

Automatic will cost you 10 mpg on this car, but you're still low. I would expect 35 to 40 from a 3 cyl auto (aside to Mike, the first 4 cylinder Metro was in 95). Mike's given you good ideas, to check timing, you need a timing light. If you don't have one, take it to a mechanic and get him to check it, have him check the compression too. These engines are famous for burned valves, more so with an automatic as it turns much faster. An auto with 100K has turned as many times as a manual with 140K.

[RossT]

I have had several automatic with the 3 cyl. they are typically only good for 30-35 in town. I have found that adjusting the timing a few degrees to about 8 or 9 will increase the mileage (as long as you don't get pinging). Also a new 02 sensor helps, and even a new or rebuilt fuel injector will do amazing things to your mileage.

[carpenter_jai]

What's your driving style? At granny acceleration and no speeding I get 47 MPG and with weaving around cars and jumping off the light I get 31 MPG in the same car.

Jai

[ammcf1]

Thanks for all the helpful suggestions. I'm in the process of doing basic tune-up (cap, rotor, plugs, wires) and a fuel filter.

Regarding my driving style, well, I'm not the lightest foot - that's for sure.

I'm just curious - why does the automatic transmission make that much of a difference in fuel economy? I'm pretty novice at all this...

[Woodie83]

You notice how your engine speed drops each time the auto shifts into a higher gear? Now imagine it did that two more times. Plus, it weighs more and autos slip a little bit in normal operation. Manuals have five gears and no slip.

[RossT]

Also highway miles suffer cause it's only a 3 speed and they wind up to a high rpm. No overdrive or 4th gear to lower the rpms. I rath like my automatics and they tend to be built really well, or at least the serveral that I have owned.