Newly purchased 97 GSR - getting 220-ish miles per tank.

Checked the air filter - it looks almost new.

I'm leaning towards plugged cat.

Seems like it's low on power, but doesn't smoke like mad. No cels.

Could just be coming from my GTI, which was 220-ish WHP with actual torque.

Would a plugged cat cause **** mileage?

 

220 miles per tank may be perfectly normal. Or, it may not be. It depends on how many gallons you have to fill it with.

If you'd like to tell us how many miles PER GALLON you're using, we'll have a better idea of what your gas mileage is.

Gas mileage in the mid twenties in a mix of around town driving with some highway miles, thirtyish on a long trip, is normal.

 

If everything else seems fine and the car is well serviced then change the O2 sensor as its the likely problem for poor mpg figures and no they wont throw a CEL until they are completely dead.

 

Depends on how u drive and stuff too. What did you used to get???

 

^^ what he said

If you're putting in 9 gal. then that's 24 mpg. Fuel economy will also suffer in the winter time.

 

compression will lower mpg as well.

 

try to replace the fuel filter also... i did that on my gsr and it helped me...

 

an o2 sensor will throw a code for slow reaction. like the other guys say start by checking how many gallons you fill vs. how many miles. i just bought a 1998 GSR and i got 245 miles to my tank and it was an avg of 27mpg city and highway. i saw that the dc2 has a 11 gallon tank but i have not been able to put more than 9 gallons in. also where do you live as altitude and temp are all factors.

 

also forgot to mention a plugged cat will effect mileage and performance... how does the car rev? if the vehicle is not in gear and revs slow you may suspect a plugged cat. ignition timing can aslo play a role here.

 

I'm getting about 20-22 miles PER GALLON.

 

There are a lot of things that affect fuel economy, some you can do something about, others you can't

How you drive
Fuel mixture (winter fuel is different than summer and I think produces less energy when it burns)
Temperature (heating the engine block costs fuel and drivetrain resistance is greater when it's cold)
Winter tires can increase fuel consumption
Warming up the car causes economy to plummet
Clogged catalytic converter
Clogged fuel filter
Other ignition or fuel system problems
Poor tune
Bad oxygen sensors
Dropped compression

and many other things I'm sure...

 

Yup. 20-22 is a bit on the low side, but not ridiculously so. My advice is to average your mileage over several tankfuls as a double-check. If you're still consistently getting 20-22, you can check the things noted above.

One other possibility not mentioned - if you're using tires with a larger outer diameter than stock, the miles shown on your odometer is less than your actual miles.

 

I would expect more mileage than that. I'm getting 22-24 mpg driving in city on E85...and i dont have a light right foot.

As previously mentioned, there are a number of things that could independently or jointly impact your gas mileage. This may not be a 1-faceted approach