Something’s been going on and after eliminating all the basic possibilities I’m nearly stumped.
Up until a few months ago I was averaging ~24 MPG in the Subaru mostly city driving, ~21 MPG if I was a little bit harsh on it, then a few things changed and I started seeing ~17/18 MPG in the city, but even highway miles don’t do much better.
The only thing that I changed aerodynamically was the edition of the roof rack, but especially in 95% city driving over the last month or so, under 50 mph, with a deflector I should not have seen a 6mpg hit, 2 at best.
So I started eliminating the possibilities
Tires all even pressure.
Alignment done.
Plugs, Wires, Air filter.
Exhaust leak fixed.
Headgasket replaced (thought the loss of compression would definitely be the key… nope).
Still getting the same old sad mileage that I’ve gotten, with no improvements.
No leaks anywhere around the car, gas or otherwise.
I’m lucky to get just over 300 miles now days on my 16 gallon tank.
The only thing I possibly have in mind is the fuel filter, no matter how unlikely that is.
Injector cleaning agent was used to (Lucas).
Engine was recently out of the car to do the headwork, timing belt is new, water pump and pretty much all gaskets and the entire cooling system is new. Diff fluids changed to synthetic Mobil 1 as well.
I got terrible gas mileage in my gsr a few years ago, no CEL and i just decided to replace the o2 for shits. After that i got 100 more miles to every tank. So my o2 was bad and didnt even throw the code.
i dont know how much an o2 is for that thing but it was only $30 for me so i figured i try it, its not likely that your o2 is bad without throwing a code i was throwin in what happened to me. If you waste you money dont blame me lol
Honestly, mine was about the same, mileage-wise. If I babied it with high tire pressures (being like 75% of it highway driving) I’d hit like 27mpg on a miraculous tankful, sometimes as low as 24.
Definitely check the fuel filter- I had done mine on the Impreza, made a noticeable difference on the mileage (sometimes I hit 30- friggin miracle!)
The primary O2 sensor, very well ‘could’ make a big difference as well, I’m sure there’s a good way to check readings, but I can’t think right now- in another beer I’ll be asleep.
Oh yeah- if you didn’t change the primary O2 after fixing the head gasket problem, DEFINITELY do that. There’s probably a good amount of crap built up on it.
yeah good call on the oxygen sensor and fuel filter… oxygen sensors for subarus are rediculous in price though… go see fred at capitalland and tell him ur on unysoc and he will usually give u a deal.
its the alcohaul or ethanol in the fuel, and it beein winter . that beein said its not uncommon for cars to get worse fuel mileage when its real cold as the air is dense and needs more fuel to stay in the sweet spot
I’m going to try next to eliminate most of the other things out of the equation and take a long highway drive, most likely when I go to hit up a mountain next time.
Fill up before leaving, and fill up when I get there and see what I get straight highway, eliminating such things as warm up and other potentials.
im deff not discounting o2 sensors and a proper tune up so dont take it that way but i see it all day ,customers walk in i want a tune up shitty mileage this and that ,guess what its only like 1 mpg better ,i also see that ya runnin lucas gas treatment ,shit is overpriced junk go to a shop that sells b/g chemicals and get a can of 44k its like 20 bucks at least what we get it for use that wit a full tank run it almost empty then refill shit is marvelous
wish i found it. on another note, it made a great 50cc garage. 