How much miles on exactly 1/2 tank form full?
 

Hello

I get the feeling I am not getting the correct miles from my SVX. I don't know what I get total on a full tank yet as I have not had it long. I do know that I have driven it to empty twice, never saw a low fuel indicator (does it have one?), and feel like I have filled it too many times. I recently filled it to the top with premium grade and reset the trip counter. I have reached exactly half a tank so far with a mix of city and highway and have only reached 88 miles at this half way mark.
The car
97 AWD with 47000 original miles
New winter tires
Still has original spark plugs from what I was told
All fluids are new
No issues seen, heard, or known
No snow yet
Regular driving style and no flooring.

I am sure that something is off. At this rate I will get just 170 miles on a full tank.l not to mention that the second half usually goes faster.

So, what should I get at the half way point and how much on a full tank with premium on a AWD model assuming everything is working as it should? How many gallons does the tank hold, it seems small as when I filled it it do not cost much.

If my car is poor on consumption what should I look at? I would assume the sparks but anything else?

Thanks in advance

Max

Re: How much miles on exactly 1/2 tank form full?
 

Yeah I see my 2nd half of the tank go much quicker then the first half. I'd suggest spark plugs (have fun :lol:) and air filter. Considering it has been sitting for awhile maybe give it some time. Believe it is an 18 gallon tank but I have never put more then 13 gallons in.

I average about 200 miles a tank pure city driving.

Re: How much miles on exactly 1/2 tank form full?
 

Max, as svx owner's we all deal with similar issues, those being... high likelihood of experiencing prematurely warped rotors, early failing wheel bearings, failing stock transmissions, streaks in our lower portions of glass, yellow headlights and of course....the pessimistic gas gauge.

My gas gauge does not read accurately. The exact cause? Not quite sure, hasn't been big enough of an issue for me to investigate.

However, I can say that once the needle hits the "E" I have at least 100 miles remaining, once the orange light comes on I have about 60 miles till I am completely empty. I have a 92 with approximately 130k miles and I get about 450 miles to the tank, which is pretty accurate.

Re: How much miles on exactly 1/2 tank form full?
 

Ditto. I'm up to 269K now on my '92 Claret.
I know I can do an easy 360miles on a tank, and have pushed it to 390+ before freakin about the chance of running out.

Re: How much miles on exactly 1/2 tank form full?
 

On my trip between Reno, NV and Orange County, id get about 200 miles before crossing below half tank, doing about 65-70mph. But when id fill up from there, itd only take about 7 gallons..... meaning the SVX has one hell of a reserve. Your gas gauge works off of resistance.... so id bet somewhere in the sender wire you have some extra resistance, or for some reason you are getting HORRID mileage. Id drive it from full to empty with someone following you with a 5 gallon gas can, at least after you hit E, to see if its just your gauge before you spend gobs of time or money diagnosing a problem that might not exist.

Re: How much miles on exactly 1/2 tank form full?
 

i was at about 390 miles first drive on my svx filled up and still had about 6 gallons left...
25.7+mpg first 760 miles for my car

Re: How much miles on exactly 1/2 tank form full?
 

Highway driving I get over 100 miles at each 1/4 tank mark. Usually ends up around 25-26mpg.

Re: How much miles on exactly 1/2 tank form full?
 

What you need to do is this. Fill up the tank, reset the trip OD, drive for however long and however far you desire. I would at least try to use a half a tank or so to get an accurate number. Fill up your tank once again and see how many gallons it took. Then do some division to check your MPG. Here's what mine is

Filled up tank
drove 255 miles
filled up tank again
took about 13.5 gallons to fill it up

255/13.5 = 18.8 MPG

This is all city driving on a 94LS FWD with 157,xxx miles using 93 octane just for reference. And BTW I don't get on the gas that hard ever.

Re: How much miles on exactly 1/2 tank form full?
 

also the gas tank is split cus of the drive shaft so there is a pump that pumps the gas from one side to the other where its picked up by the main fuel pump. sometimes the transfer pump goes out don't know if there are any fues for that... but i would do what everyone else is saying first before really looking into this..

Re: How much miles on exactly 1/2 tank form full?
 

<<also the gas tank is split cus of the drive shaft so there is a pump that pumps the gas from one side to the other where its picked up by the main fuel pump. sometimes the transfer pump goes out don't know if there are any fues for that... >>

WHAT?

Re: How much miles on exactly 1/2 tank form full?
 

This question has been kicked around for years. As I recall, from some old posts, the float device in the tank is made of some sort of material that absorbs gas, gets heavy, thus "sags", giving a pessimistic reading throughout its range. Typically when you hit the empty line, there's probably another 80-100 miles left for your driving pleasure. On a trip long ago with gentle driving most of the time, I squeezed 400 miles out of the tank before the "low" light did its thing. I drove another 20 miles to a station, filled her up, & only managed to cram in about 17 gallons. Assuming I was getting roughly 25 mpg, an 18 gallon tank would be good for 450 miles.

Ron.

Re: How much miles on exactly 1/2 tank form full?
 

yea look at your tank its like a saddel bag on a horse

Re: How much miles on exactly 1/2 tank form full?
 

Hello All,

Thanks for all this info thus far.

I don't really care if the car is poor on gas consumption (well sort of), rather I should say more, I just want it working as it should. If its suppose to get 200 miles per tank which I find very low of an 18 gallon 70 liter tank then I know my car is running fine. But, if its suppose to be 300-400 then I want to find the issue and resolve it.

I have checked the AIR FILTER and it is brand new, along with the tires (and correct pressure all around), the battery, and all the breaks (including rotors/discs and pad). The transmission is perfect. Bearings, I don't hear them and at least the two rears are new thus I assume they are fine.

Like suggested filled it up today, it was just slightly below the half mark but more so at half line, and I and managed to squeeze in 26.9 Liters or 7.11 US Gallons. If its a 70 liter tank then I should have been able to put in some 35 Liters. Maybe the gauge is off?

This morning I reset the trip computer again and added fuel injector cleaner aside from the premium fuel fill up. I will run it down to empty via the gauge and see what happens next but at this rate I think it will be by Monday. The Subaru dealer that checked the car in March of 2008 (and its only done some 200 to 500 miles since) said the spark plugs were fine so the owner left them as is, however, they are the originals and now 11 years +. I assume it would be a good idea to change them as I would think they can't still be good or like the Dealer said do you think they are fine? The car has just 47000 gentle one owner original miles. Due sparks wear with and or miles or both?

Thanks again,

Max

Re: How much miles on exactly 1/2 tank form full?
 

Yes, as others have stated, the gauge tends to be pessimistic. One of mine was well below the 1/4 tank mark recently but held only about 13 gallons. You can accurately measure fuel economy ONLY by keeping tabs on actual fuel consumed in a known span of miles. Don't spend money trying to improve your MPG until you've established firm mileage numbers.

dcb