I have 4 tanks through my new(?) 89 S2 now. It looks like it's going to be 14mpg on premium of course. The car does have a chip but is otherwise unmodified. My 86 na gets 19mpg city.
No, I didin't buy it as an economy move, but this may effect my ability to make it my daily driver. Do I need to see my mechanic, or, is this typical? BTW, the car flew through the smog test here.
Thanks, Scott

 

I have an S2 that's getting 28mpg on highway -- I haven't had the opportunity to measure city mpg. But your 14mpg is pretty bad! If you do a search, you'll find that oxygen sensor is a common culprit for bad mpg. Replacing it might be the solution.

 

Yes, replace the O2 sensor before you clog up the cat. I get 18-19 MPG in the city leadfooting around.

-Joel.

 

Thanks,the 02 sensor was the first thing my mechanic mentioned as well. I will persue it.
Scott

 

I get about 21 MPG with a pretty heavy foot in the city. I have a Chip from Steve R and it hasnt made my fuel economy any worst. In fact, it prolly let me hold taller gears longer with the extra torque but then it also made me wanna floor it more. Maybe try to clean ur injectors with a bottle of STP. That helped a bit when I first got my car.

 

I would be carefull about additives, when i first got my car they put carbon build up cleaner in my gas and instantly the exhaust was pouring black smoke, they claimed it was normal but after three hours of black smoke and a nasty ticking/knocking noise i took it in. The cylinder sleeves as it turns out are teflon coated and too harsh a chemical eats them away. So my pistons were beating themsevles against the cylinder wall. $5,500 dollars and six months later i got y bored out motor back good as new. STP is probably a safe product though...

 

I would recommend cleaning you fuel injectors by removing them. Pelican Products has a good DIY procedure on there website. I do it every 50k and will be doing it probably next week on my car. You would be surprised how nasty the injectors look when you pull them!

 

14 is very bad..

Check compression...

 

Yeah, even with autocross and city with only slight highway i see at least 18mpg. Somewhere in the low 20s is more normal. On highway I have seen over 32mpg doing 80mph steady.

 

Blow me 14mpg! I don't know why but I get @least 30+mpg. On long runs it's got to be in the order of 30-35mpg. Not sure what the offical figures are though any idea?

 

Combined city and hard backroads driving I get 21-23, and between 27-30 on highway trips. I'd be suspicious unless you got the little known factory 3.5L option, haha.

 

I had the 02 sensor replaced and it seems like the mileage has improved some.
I will have to wait to fill the tank as some of the mileage was with the old sensor.
Thanks for your responses and I will let you all know what I find out soon.
Scott

 

I'm an aussie S2 owner and the worst i have had is 12L/100km (19.6mpg) but run pretty consitant 10L/100 for mixed driving (23.5mpg)
However i know of a fellow S2 owner who cannot seem to get better than 14L/100km (16mpg) (i suspect his driving style has more to do with it than anything else though)

 

why are you driving your S2 in the city? aren't the roads beating the hell out of the suspension, or is it just new york city that has washbord streets. i know mine is not a comfortable ride on city streets at all! much too harsh. also i hope you get onto an open road once in a while and let the 3 litre breathe a little and stretch out, they seem to like that much more. i get over 21 mpg highway, cuty i really don't know.

 

That is one of the biggest loads of crap i have heard in a while...the cylinders are not teflon coated...they are alusil or nikasil.