I bought a used 93 Saturn SL2 , only 40,000 miles, but the MPG is only 17 in local/city condition,...., what tthe problem may be? but from the http://www.fueleconomy.gov, the MPG of saturn sl2 is pretty good.


what I should do to improve the MPG, check what? thanks.

 

That doesn't sound right. My 94 SL1 with 135k miles still gets an honest 30 MPG in mixed driving.


I would always start with the spark plugs and wires, but that's too much off for those I think. You might check your air filter too. Again, it would have to be pretty clogged.


Could be your ECTS. I know that if these fail, they can reduce your fuel economy, but I don't know by how much.


EGR maybe? Edited by: CALegalVette

 

Hi, CALegalVette,thanks.


how to check it? can I do it by myself ?
I mean, are many tools needed to open it?
and, is the air filter can use any kind of air filter in the same size or I can only use that come from Saturn?


willer

 

Not really anything special required.


I prefer FRAM air filters rather than Saturn because I'm cheep.


Don't know how to check ECTS. Derf will probably chime in and he'll know how.


You don't really check spark plugs. if you bother to remove them, you might as well replace them.


EGR valve is a little harder to get to and test.

 

oh, what is ECTS and EGR? I am sorry, I am a new driver...,


So , the most easiest thing is to check the Air Filters, then the spark plugs, then...EGR, ECTS?


According to your information, so the Air Filters are not required to use the parts from Saturn? then that is good, haha.Edited by: willer

 

40K on a 93?

Pardon me for being skeptical, but unless it has been in a barn somewhere for a decade or in grandma's garage flat-spotting the tires, I'd suspect someone swapped out the speedo/odo.

Of course if you got this from someone you know and trust, then I'll sit corrected.....
_____________

Anyway, ECTS (Engine Coolant Temp Sensor) is undoubtedly the original if the mileage is true -- and has failed (they all did -- poor design).
_____________
For the record:

ECTS is a resistive device whose resistance value changes with temperature. Resistance decreases as temp increases for this particular sensor. Resistance reading across properly functioning sensor with engine at operating temp should be in the range of 225-275 Ohms. This corresponds to about 190 F coolant temp.

If you're getting readings much higher than that at operating temperature (at idle) , your ECTS is likely bad.
______________
1) Replace with brass tipped replacement ECTS. Replace the ECTS connector as well (Saturn only part). Corrosion here is a killer. Bad ECTS causes car to run way rich.

2) Recommend
a)new plugs and wires
b)a throttle body cleaning
c)Clean the corrosion off of the coil posts with a very fine emory cloth (extra fine grit sandpaper)
d)injector flush

3) Wouldn't be too concerned with EGR if it truly has only 40K on
it-- probably not enough carbon buildup to be worried about. Also, EGR issues usually manifest as driveability issues.

4) How much oil does it burn between changes? Keep it topped off.

5) Service Engine Soon (SES) light on?

Keep us posted

Derf

 

Thanks, Derf,


Yes, when I see this year and this mileage, I can not believe it, but when I check the history , it is very clear, and the body is pretty good, except for some old part which is plastic material, the tires are still like new .


I just think itwas a car owned by a old man , and did not drive frequently. Or like you says, "it has been in a barn somewhere for a decade or in grandma's garage flat-spotting the tires"


I need some time to understand your post and reply again.


thanks again.

 

Thank you again.

 

I'm also curious about your style of city driving. My 95 SL-1 (150K miles and a manual transmission) will routinely get 34 mpg in my normal mixed driving but for a couple of years when I was only driving about 3 miles to and from work, lots of stops and starts and a school zone, I was probably getting about 16.

 

My 93 SL1 is getting about 28 MPG mixed, but more short trips than long. I plan a trip in a couple month's, I'll see what it does on the interstate.